MANUFACTURING HEAT TREAT TECH

Heat Treat Radio #133: Process Qualification & Recipe Development in Vacuum Carburizing

/ HARDENING TECHNICAL CONTENT, HEAT TREAT RADIO, MANUFACTURING HEAT TREAT TECH, VACUUM FURNACES TECHNICAL CONTENT

Heat Treat Radio host Heather Falcone and guest Vincent Lelong, Senior Synergy Center Manager and Metallurgist at ECM USA, explore the realities of process qualification and recipe development in modern heat treating. Vincent shares decades of experience developing vacuum carburizing processes for automotive, aerospace, and high-volume manufacturing applications. Together, they discuss how heat treaters can balance metallurgy, fixturing, quench strategy, and production demands to achieve repeatable results. From practical troubleshooting insights to the evolution of vacuum carburizing technology, this conversation offers a grounded look at what it takes to optimize heat treating.

Below, you can watch the video, listen to the podcast by clicking on the audio play button, or read an edited transcript.

The following transcript has been edited for your reading enjoyment.

Introduction (00:05)

Heather Falcone: Hi, I’m Heather Falcone, and welcome to Heat Treat Radio. Today, we are asking a metallurgist, and we are talking about the ins and outs of process qualification and recipe development. We are on-site with the sponsor of our episode, ECM USA, in beautiful Pleasant Prairie, Wisconsin. It’s a real treat to be able to record on site. We hardly ever get that chance. Joining me today is Vincent Lelong, the Senior Synergy Center Manager and Metallurgist. Thanks for joining me today, Vincent.

Vincent Lelong: Thank you, Heather.

Heather Falcone: So you have the luxury, since we are in your beautiful facility, to tell me not just about yourself, but also about ECM. Start off with your background because it is extensive.

Vincent Lelong: I am a metallurgist, I went to college in France, and I started with ECM in 1999. Since then, I’ve been across the world in the U.S. for 20 years. I do presentation and testing for the furnace behind us and our larger furnace. I go on-site. This is our Synergy Center; it’s a nice environment, clean — quiet today because we’re filming.

Heather Falcone: Tell me a little bit about what ECM does.

Vincent Lelong: At ECM, we manufacture and install heat treatment vacuum furnaces. Our main focus is on low-pressure carburizing modular furnaces, large and small. We integrate not just heat treatment itself, but the pre-treatment, like washing, storage, preparation of the load with robots, heat treatment, temper, cryo… Everything is set up together, and that is our main goal: integration of a fully automatic installation.

Heather Falcone: A one-stop shop. You go to one place, and you’re going to make it all work.

Vincent Lelong: There’s a part and everything will be ready in few hours later, sometimes days, depending on the treatment.

Heather Falcone: Hopefully it all works.

ECM Nano vacuum furnace used for client cycle development and qualification.

Vincent Lelong: Well, it always works. It’s a really repeatable modular furnace. In the U.S., we are focusing on vacuum carburizing, but we also manufacture other types of furnaces for crystal growth, silicon heat treatment, melting silicon for solar panel, and others. Within ECM Group, there’s a range of heat treatment processes that we manufacture for. And not just steel; it can be other materials. I’m specialized in steel and very restricted heat treatment with vacuum carburizing, but maybe one day we can do other materials.

Heather Falcone: Steel makes the world run.

Vincent Lelong: With our modular furnace, we can do hardening, gas quench, oil quench, carburizing, gas quench, oil quench, and now we do vacuum carbonitriding and we can do nitriding in the furnace. So you can have one installation for multitask heat treatment. It’s the purpose of the modular furnace, the beauty of it.

Heather Falcone: More flexibility, more capabilities.

Biggest Challenges of Process Qualification and Recipe Development (4:08)

Heather Falcone: That brings us into the first core question that I want to ask, because when you’re evaluating bringing in another piece of equipment or if you’re trying to bring on a new process, it can be a little challenging. What do you see are the biggest pitfalls or what do you see people struggling with most when it comes to process qualification and recipe development?

Vincent Lelong: Most customers say, “I would like a good metallurgy. I would like mechanical properties.”

Heather Falcone: Right, make good parts. That’s number one.

Vincent Lelong: But you need to look at what kind of furnace you would like to use, as well as the size, the type of part, and the process. If you have a small part, do you want a bulk load? Do you want special fixtures because the main target is distortion-free? Everybody would like everything…

Heather Falcone: …distortion-free!

Vincent Lelong: Always. No problem. So, as a metallurgist, you need to think not just about heat treatment because you’ve been asked to heat treat a part. I could heat and quench in oil and say, “You have the metallurgy. My job is done.”

Heather Falcone: Right. It hit hardness.

Vincent Lelong: Exactly. Hardness, good. Vacuum carburizing, no oxidation. Good. How about the distortion? Okay, let’s speak about what we can do to reduce the power of the heat treatment itself. Then, let’s do a gas quench, but let’s work on fixtures also. It’s working with the supplier for fixtures and working with the customer with the machinists.

Sometimes, because we propose gas quench, people say, “Oh, gas quench means no distortion.” Well, the first step is to get the metallurgy right. If you need 20 bar gas quench, you might have some distortion. From experience, we know that the fixtures are also important. So we can work with the customer and supplier to propose the right fixtures and test the fixtures to target the best cooling rate and other properties.

But we also need to work with the machinists. If you have a challenging part, machinists may say, “It’s the fault of the metallurgist.” And the heat treater will say, “No, let’s work together at the table. We’ll sit, and we do the testing.” At the Synergy Center we have also the CMM, so we can measure before heat treatment and after heat treatment. It’s the best feeling when you bring not just the metallurgists together, but also the people who make the part. We work together to have the best of the best. It’s a lot of work, but we have years of experience, so we can reach the target faster than 20 years ago.

Technology has changed. As such, you also need to work with the steel manufacturer, the way the steel is made and the composition. Research has shown that if you improve the steel, you can reduce the quench pressure. If you need oil quench, then you already know that distortion will be potentially higher. If you need 20 bar, it’s one thing. Well, I did a presentation not long ago, and I found that the distortion with 10 bar or 20 bar in a Nano furnace was much better than in a larger load. For one part, that is. This might not be true if it’s other parts. There’s always that phrase in heat treatment, “that depends.” I don’t like this phrase.

Heather Falcone: It always depends.

Vincent Lelong: But it’s true, unfortunately. So, when you have worked all that together, you can bring the best analysis. I’m working before that to sell a furnace.

I need to choose whether it’s better for the customer to have a smaller furnace or a larger installation. That really depends on how many parts, the diversity of parts. If the customer has mostly small parts, the Nano may be the better choice. You have a faster answer because it’s in and out. You don’t need to buy so many fixtures. But if you have a larger part, a larger furnace is better. It’s not whether one furnace is better than the other. You need to choose which one will achieve your production target.

A customer in facility number A may need a larger furnace, but in facility B, there are other types of part, so that facility may need a smaller furnace. That’s how we work with the customer to target what is important.

Heather Falcone: Pick the right atmosphere, pick the right hot zone size, pick the right fixturing, raw material specs. All of those are going to influence how the runs going to go. I bet you have some stories about TCE from fixturing and eutectic and inadvertent bonding.

Vincent Lelong: I certainly have had a few mistakes in testing. I used a higher temperature because with vacuum carburizing we say we can go to a higher temperature. But then I used CFC fixtures at the wrong temperature!

Today however, the mixtures of fixtures can work and reduce the weight. As a metallurgist and a heat treater, I prefer to heat treat the part rather than the fixtures. When I see a customer running a load with almost more fixtures than parts, I’m asking, “What do you heat treat?” Are you losing money on heat treating fixtures more than parts?”

Heather Falcone: There is such a big weight differential between fixturing and the parts. How much lag time on your heat up and cool down are you wasting on having too much fixturing?

Vincent Lelong: It’s true.

Balancing Technical Requirements with Production (11:30)

Heather Falcone: Once you’re in recipe development, how do you balance technical requirements, the repeatability, and the realities of production?

Vincent Lelong: Repeatability is firstly about how you design the load. Then you need to know the quantity of parts. You also may know the surface of your load, but it may always be necessary, I will say. Most of the time we don’t know that and it still runs correctly.

Heather Falcone: Still a black box. It’s an art what we do.

Vincent Lelong: Technically, it’s a good thing because when we put something inside the furnace, it’s coming back, and we don’t see much difference. But the mechanical properties are completely different, so it is kind of like magic.

So you define your load, you define your heating time to get temperature, and when you’re sure you’re at temperature, you start to carburize. I will speak about vacuum carburizing. First, we have software for the carburizing boost and diffusion; you input your parameters and then you have your recipe. You can run it generic, or you can go into detail and improve it. But as built, the software will give you some set parameters and will work.

Heather Falcone: Technology is so cool.

Vincent Lelong: It’s getting better and better. You will also need to select the type of furnace. When you have one part, it’s not the same as when you have 3,000 parts. The density of the load will influence your gas flow and the capacity of your installation.

Most of our larger furnaces have a maximum of acetylene of 4,000 liters. But you can play with the gas and the duration of the boost and diffusion so it goes inside the part; when you have a blind hole or you need 3 millimeters, you carburize. (Acetylene is beautiful, but molecules can go everywhere, sometimes where we don’t want acetylene, which is why we have the stop off.) But you define your load, you define your recipe, your gas flow, and then you run a test and analyze the metallurgy. If it’s good, then you’re done and you don’t move from that.

Heather Falcone: That’s what production wants to hear.

Vincent Lelong: When you are a heat treater, you may receive 10 parts to heat treat. Tomorrow you may receive 20 parts, and maybe you need to run the same recipe. In general, you can run the same recipe for 10 parts or 20 parts. You would use the parameters of the larger load for the smaller, if possible. The result will be mostly the same, but the cost will not be the same.

This is where you can optimize your recipe for different types of load, like half of the load versus a full load. You can change the flow of gas, and then reduce your heating time because why set for two hours when in one hour, it is at temperature. One hour is money.

Heather Falcone: Got to turn and burn.

Vincent Lelong: This is also where you define your database and your repeatability. I once had a customer that had me create a recipe for a specific quantity of parts and a design of load. A few years later, that customer called and said, “It doesn’t work.” With modern heat treating controls, we record everything, so you have a database, the curves, and you can go back and see what was wrong.

Heather Falcone: Right. What changed?

Vincent Lelong: In this case, I discovered the customer was running the double quantity of parts in the same load without changing the recipe at all.

Heather Falcone: Makes sense. Start there.

Vincent Lelong: Heating time was not long enough. Gas flow was not long enough. And they were not working at the right pressure in the furnace, so failure occurred. I said, “Change that.” No news is good news usually. If the customer doesn’t call you, it’s because…

Heather Falcone: …Everything works.

Vincent Lelong: That’s the beauty of this furnace.

With repeatability, you always need to look at the curves. If you have an issue of temperature out of the range, there will be an alarm. So, you can check if the part is good without checking the metallurgy. If you heat treat a big part, usually you won’t cut the part. If you have six parts in a load or 10, you have samples. You have to validate your sample and your real part at the beginning.

Heather Falcone: To make sure it’s representative.

Vincent Lelong: Exactly, or if there are differences because you cannot find exactly the same material, you know the difference, and the difference would be always the same.

Heather Falcone: Right. Make it predictable.

Vincent Lelong: We have some customers that would check one load per day or per shift and not every load. If you have 3,000 parts in a load, you can check a part. When you have six parts, you will likely not cut a part. If the furnace tells you it’s good, why check? When you check repeatability, you still need a lab. Not checking the metallurgy is difficult. You should always check again. Repeatability shouldn’t be left to chance or statistics. Take a part and check. Is it good? Then continue.

Heather Falcone: That’s kind of the target of qualification, right? To get those parameters that you predefined.

Vincent Lelong: In time you need to be sure nothing changes.

Heather Falcone: What does re-qualifying look like?

Vincent Lelong: You want to be sure that nothing changes, material-wise. Sometimes, you run the same material, and you achieve 35 HRC. But at one point in time, you achieved only 25 HRC. This is the same material on the paper, but something has happened. So you need to go back in time and figure out what was originally going on. Is it the heat treatment? Is the installation of something around it?

Heather Falcone: Use all the data that’s available to you.

Vincent Lelong: This is where you check the productivity.

Quench Media (19:20)

Heather Falcone: How about the quench media?

Vincent Lelong: When you develop a recipe, if you do oil quenching you will always do austenitizing. You don’t want a crack. You will carburize, austenitize, and go to oil quench. It’s pretty easy to switch from atmosphere oil quench to vacuum oil quench because technically the recipe is pretty much the same, and we’re going to cover that ground extensively because I know it’s kind of scary to even consider that possibility.

When you go with gas quench, if you don’t know the target or are unsure, you select 20 bar.

Heather Falcone: Sure, 20 bar. That’s the easiest in the world.

Vincent Lelong: Exactly. You do 20 bar and you get what you get. There is an advantage of the gas quench. Many customers will ask, “Do I need to do a direct quench? Do I need to do austenitizing?” Most of the time we say direct quench, and we found that you don’t crack with gas quench. Whatever the pressure, we never really have much cracking. Or a customer may ask, “Will the part break due to the gas quench?” That will never happen. I once asked the competition if they ever saw a crack with gas quenching and they said no. It’s the way the gas quench quenches and cools the part down, then it’s less powerful than the liquid, so you don’t have this potential issue.

But if you don’t know, you stay at 20 bar. If you would like to optimize, you can reduce, but you need to achieve the target metallurgy.

Heather Falcone: Right. You’ve got to get your core hardness.

Vincent Lelong: Your limit is when your metallurgy is not right. When you reduce, you reduce the cost. If you reduce the pressure and the speed, you will reduce the distortion potential.

Heather Falcone: Which is always a good thing.

Vincent Lelong: If you have a shaft, you should not place it horizontal, because whenever you quench that, it will not be straight.

Heather Falcone: We’ve potato chipped a few parts over the years, yes.

Vincent Lelong: Me too. I have tried horizontal in some cases. It’s interesting, but you need more support. I think it’s possible, but nobody wants to try it.

Heather Falcone: Why bother?

Vincent Lelong: Vertical is easier.

Heather Falcone: If you’re qualifying, just make the fixture that’s going to support it.

Vincent Lelong: Yes. Why should I change? It’s always a big question; we just quench it vertically this way. We do it this way. Now for gears, in heat treat sites I see a lot of vertical positions for gears strung on a rod. As an operator, I don’t like that.

Heather Falcone: Tell me why.

Vincent Lelong: Because it’s heavy. We already have difficulty finding operators in heat treatment. If it’s heavy, nobody wants to do it.

From a robotic point of view, it’s more difficult, too. Today, with most vacuum carburized and gas quenched gears are heat treated horizontally on fixtures and most of the time with offset position. That will give you the best metallurgy, but also the least distortion overall. Vertically for machinists, it’s very difficult to re-machine something round to oval. When you place it horizontally, you can do potato chips but machinists can grind and reshape the part easily, if it’s possible.

Heather Falcone: If you’re already near net, it’s going to be a different story.

Vincent Lelong: Exactly. That’s where when you check your distortion and repeatability of process — it’s the fixtures.

Heather Falcone: I would think working with the customer as much as you can to see if material can be left on the part too, if we do need to have grinding, if we do need to have repair or recovery for any possible distortion.

Vincent Lelong: So, let’s say we are working on a six-speed. For the six-speed, everybody wants to vacuum carburizing gas quench. The objective: zero distortion, heat treat, and assemble.

Heather Falcone: In theory.

Vincent Lelong: No, in truth.

Heather Falcone: Really? Okay.

Vincent Lelong: That was the target.

Heather Falcone: Ambitious, I like it.

Vincent Lelong: Yes, but when you have a new product, you can use new technology, you can work on the fixtures, you can work on everything. We worked a lot with car manufacturers to do the best heat treatment, the best fixtures, the maximum of parts, of course, and repeatability. This furnace is running millions of parts.

That is why we know vacuum carburizing works and it’s repeatable. For this high volume, we had to work on zero distortion. But the specification then didn’t change, metallurgically speaking. Most of the time it was 0.3 to 0.7 millimeters. It’s a large gap. No problem. Then we went to the 10-speed for most of the automotive, and then the distortion was the target because of the experience we gained with the six-speed, which was the noise. People don’t want the noise. Today, with the 10-speed, we start to grind at 0.1 millimeter.

You have to compensate for your carburizing process so that it is longer and deeper, but also most customers will reduce the metallurgical requirements. From 0.3 to 0.7, they want 0.5 plus or minus 0.05, which is much thinner. With electrical applications today, you want zero noise, because you can hear everything. There’s a lot of grinding, and when I say a lot, I mean exact, 0.2 millimeter.

Heather Falcone: That is a lot of post-process work.

Vincent Lelong: You have the perfect teeth. You need to anticipate longer carburizing, and it’s great! Also, what I see with metallurgy, it’s not that you don’t have a general metallurgical specification, but each area of a part will have its own metallurgy. That means you have the pitch of the gear, the roots, a minimum, but sometimes you have a specification of the tip.

A customer may specify, “I don’t want more than 0.8.”

Heather Falcone: Just for that area.

Vincent Lelong: Yes. As the parts get more and more complex, they have more than just one application or function. You have the spline. You have double teeth. Each one will have its own requirement. With an atmospheric furnace, to get that, it doesn’t work very well. But with vacuum carburizing, you can achieve very precise requirements.

Switching from Atmospheric to Vacuum Carburizing (28:11)

Heather Falcone: To that point, is that one of the things that stops people from considering the change from atmospheric to vacuum carburizing, or is it part complexity?

Considering the switch? See how different carburizing technologies and furnace features stack up when you click on the image above.

Vincent Lelong: The larger companies do not seem to be afraid, because they know what they want and they already have experience. For the heat treaters, the smaller companies, it’s very difficult to switch with the requirements today. When you see the requirement on the drawing, it’s funny because before there was just heat treatment.

Heather Falcone: Yeah, it’s on this process sheet.

Vincent Lelong: One line. Surface furnace ECD, core

Heather Falcone: Right.

Vincent Lelong: Today there are different requirements, and there are several requirements: before heat treatment, after, and final. You know how much you need to take off, and not every area you take off. You said keep more material. The advantage of that is more material, less distortion. But you will have to carburize more.

Heather Falcone: Ultimately it may be more expensive for everybody.

Vincent Lelong: Exactly. The machining behind the grinding is also costly. When we develop a recipe, we have the customer machine to the final dimension, do the heat treatment, and then we will see where we are in terms of metallurgy and distortion. If we are not where we need to be, don’t take off too much. Then you adjust.

One other story is about a thread.

Heather Falcone: Oh, God, threads. The bane of every heat treater’s existence, threads.

Vincent Lelong: I get a lot of questions about threads. Do I need to make them before heat treatment? Do I need to put a mask on, paint, or make the fixture?

Heather Falcone: Texture or mechanical.

Vincent Lelong: Or to not do them and do them after?

Heather Falcone: That is also expensive.

Vincent Lelong: Yes, also expensive; but I think it could be a robotic application.

Heather Falcone: Oh true. Very good point

Vincent Lelong: It’s the way I would go.

Heather Falcone: How interesting..

Vincent Lelong: To not do the thread before.

Heather Falcone: Lower risk.

Vincent Lelong: First, when you carburize, you can create a brittleness of the thread. But also operator movement of the thread from crate to the fixtures can cause damage to the thread. What do you do? Can you save the thread after heat treatment? Not always. Then that is garbage. You had to manufacture the part, heat treat the part, just to put in the garbage, which is a cost.

Heather Falcone: Probably 80 or 90% of your whole cost, gone in an instant.

Vincent Lelong: In my opinion, you could have a robot preparing the load. You would have a robot take off, and every time it’s the same movement. Then, thread or not, it’s easier.

Heather Falcone: More predictable.

Vincent Lelong: Then the robot, if you don’t do the thread, can put the shaft, usually it’s a shaft with a right connection on the thread on the end, put to a little induction machine, reheat, and then put in a crate and go back to machining. Then it’s all done.

In that instance, I think it’s my preference not to do the thread first. I have customers who ask me for paint or for a mask. Paint is not, I would say, 100% safe. You need a specialist to put on the paint. There are some tricks, as I know heat treaters know. They have been doing this for years and they know their stuff.

Heather Falcone: That’s their secret.

Vincent Lelong: I think heat treaters have more secrets about painting and protection of the part than the big companies do. They know it better.

Heather Falcone: Their lives are on the line. That’s all they do, so they have to make it perfect.

Vincent Lelong: You can learn a lot from heat treaters. They know their work.

Heather Falcone: That’s what I always recommend to the captives. Get out to as many heat treat shops as you can, because it’s going to make your in-house heat treat better.

Vincent Lelong: They have years of experience to learn from. Heat treatment is tricks after tricks. Some customers are afraid to go to in-house heat treatment. These heat treaters hold a variety of information that is helpful for these customers.

Heather Falcone: It’s an interesting point that you brought up about being afraid, because vacuum carburizing has gotten that reputation over the years that it’s difficult. It’s tough to figure out.

Vincent Lelong: Because we did a good job. We did a good job to say you can optimize. In reality, if you understand what you want to heat treat, the carburizing process is all made by software. Every company has their own software. So it is pretty simple, and though it can still be scary for the heat treater.

Heather Falcone: Process change is scary.

Vincent Lelong: There are some companies that develop vacuum carburizing software where you need to know everything about the steel, the chemistry, all the parameters. We work with carbon. For our software, you enter the carbon content originally, roughly the temperature you would like to heat treat, and what you would like on the final. The software will give you something, and it will be 95% of what you’re looking for.

Now you need to quench. Like I said, with oil quenching, it’s no problem. Gas quenching, 20 bar, no problem, very easy and straightforward. Optimization can be where it’s trickier. But it’s just like an atmospheric furnace. I work with atmospheric furnaces, and they all have their cheat sheets.

You need carbon potential, temperature, time, and in vacuum carburizing, it’s the same thing. The temperature, your carbon potential, or what you expect for carbon, the time, the case depth you would like to achieve, and here is your process.

Heather Falcone: Then you don’t need the cheat sheet. It’s gone. Then it’s documented and repeatable.

Vincent Lelong: Right, then you have to heat up and quench. So, straight heat treatment: heat it up to be sure you’re at temperature, then carburize, and you quench.

Heather Falcone: One test?

Vincent Lelong: Yes, I often do just one test.

Customers may ask me to do a test for a Flex system, a larger system. I do it here at the Synergy Center first because it’s cheaper for me because it just value add and it’s here. I can mix a different part, different design, and run. “Oh, it’s a 8620? No problem.” Usually, it’s good.

For a Nano load, it’s like a one-fifth or it’s a one fixture and the bigger load, it’s like two column of fixtures, then you stack. So, it’s not much different. You start on a smaller scale and you go bigger, and you just add a little heat up time.

And if you ask me, “What do you need?” Put everything to the maximum!! (We are here to sell you a spare part, so, you know.) But really, if you put everything to the maximum you will be good. Maybe too good, and you might have a more maintenance, but we’d be able to provide a quote to reduce the maintenance. (*joking laughter*) 

Closing Thoughts (37:36)

Heather Falcone: As we finish up, if there’s one thing that you’d want our listeners to take away, rethinking about their approach to process qualification and recipe development, what do you want them to know?

Vincent Lelong: It’s not difficult. It’s like every other heat treatment; you have to test it and you will quickly see that it’s easy. At ECM USA, we provide training and testing to show you what can be achieved and answer your questions. If you’re worried, we will show you how easy it is, how clean it is. There’s no flame. If you have oil quench, there’s no flame because everything is protected. So it’s not difficult, it’s just one step. Do not be afraid.

Heather Falcone: Take that first step, and explore the process.

Vincent Lelong: I think there’s enough research and evidence in the last 25 years in the U.S., especially with large automotive and aerospace companies to know that it’s not a big deal. Most people — in heat treating or not — don’t like change.

Heather Falcone: But they can partner with you, Vincent, who has decades of experience. Reach out to ECM. Get in touch. Start exploring.

Vincent Lelong: The funny thing is, with decades of experience, what we are capable of heat treating 20 years ago we can do way better now. The technology is better. Gas quenching is made to quench, not to cool. It’s quenching. It’s hard. It’s almost as hard of a quench as an oil quench. You can do bulk load carburizing. I did carbonitriding in bulk load not that long ago. If you had asked me to do that 20 years ago, I would say, “No way that works.” But today that works. Just contact us.

Heather Falcone: Start the conversation, right?

Vincent Lelong: And I would be happy to show you. I like my job.

Heather Falcone: You love your job. I’m going to say it. You’re very passionate.

Vincent Lelong: I like testing because it’s a challenge every day. It’s pushing the limit. It’s like a movie. Is it possible? If you follow the book or internet, they will say no. I would say, “Let’s try.” I’m testing on materials other than steel as well that I would not have expected to work. Modular furnaces can be a very versatile.

Heather Falcone: Well it sounds like production is getting ready to get things done. Thanks so much, Vincent. It was great spending time with you.

About the Guest

Vincent Lelong
Synergy Center Manager / Sr. Metallurgist
ECM USA, INC.

Vincent Lelong, ECM USA Synergy Center Manager, transferred to ECM USA in 2005 to manage the North American Testing Program in Wisconsin after 6 years’ experience with production/testing furnaces at ECM Technologies headquarters in Grenoble, France. Vincent has degrees in Chemistry & Physics from the University of Reims, and Treatment of Materials (specializing in Heat Treatment) from BTS Roosevelt, also located in Reims, France. He began his career as a production and laboratory technician for a commercial heat treater, and joined the ECM Group in 1999 as an ECM Technician running LPC testing/metallurgical analysis within ECM vacuum furnace systems.

For more information: Contact Vincent Lelong at vincentlelong@ecm-usa.com.

Heat Treat Radio #133: Process Qualification & Recipe Development in Vacuum Carburizing Read More »

Utilization: The Hidden Sustainability Metric in Heat Treatment

/ MANUFACTURING HEAT TREAT TECH, VACUUM FURNACES TECHNICAL CONTENT

As manufacturers push toward ambitious sustainability targets, heat treatment remains both essential and energy intensive, making efficiency gains critical. In this Technical Tuesday installment, Myles McCarthy, a senior sustainability and climate leader at Bodycote, highlights utilization as a powerful, often overlooked lever, showing how maximizing furnace loading and focusing on energy per component can significantly reduce emissions and improve overall process performance.

This informative piece was first released in Heat Treat Today’s May 2026 Sustainable Heat Treat Technologies print edition.

The drive toward more sustainable manufacturing continues to gather momentum across sectors like aerospace, automotive, and advanced engineering. While political priorities may fluctuate, the direction is clear: manufacturers are under increasing pressure to reduce emissions, improve energy efficiency, and demonstrate measurable progress against ambitious environmental targets. For many organizations, thermal processing sits at the center of this challenge.

Heat treatment, hot isostatic pressing (HIP), and specialist surface technologies are essential to the performance, safety, and longevity of critical components. Without them, components would not perform as designed, leading to higher raw material consumption, increased emissions, and excessive waste. Yet, thermal processing is also one of the most energy-intensive stages of manufacturing. In some industries, thermal processing can account for 25–35% of a component’s carbon footprint.

As a result, attention is increasingly drawn not just to what processes are used, but how efficiently they are delivered.

Beyond Furnace Efficiency

Much of the conversation around sustainable heat treatment has focused on equipment: furnace design, insulation, electrification, and the transition to renewable energy sources. These are all important developments, and they continue to play a key role in reducing emissions.

However, an equally important and often overlooked factor is utilization. The energy consumed during a heat treatment cycle is largely fixed, regardless of whether a furnace is fully loaded or only partially utilized. As a result, the true energy intensity of heat treatment is not simply a function of furnace efficiency, but of energy consumed per component processed.

In practice, this means that two identical furnaces operating under different loading conditions can produce significantly different carbon outcomes.

The Impact of Underutilization

In many in-house environments, heat treatment is one step within a broader manufacturing process. Production variability, batch sizes, scheduling constraints, and part mix can all lead to suboptimal furnace loading. Partial loads, idle time between cycles, and non-continuous operation are common realities.

From an operational perspective, these challenges are often unavoidable. From a sustainability perspective, however, they have a direct impact, increasing energy consumption per component, raising associated carbon emissions and reducing overall process efficiency.

In this context, even highly efficient equipment may not deliver optimal environmental performance if it is not consistently utilized to capacity.

Utilization as a Sustainability Lever

True energy intensity needs to measure the energy consumed per component heat treated. | Image Credit: Bodycote

This raises an important question for manufacturing leaders and heat treatment engineers: What is the true energy cost per treated component, and how much of that is driven by utilization rather than technology?

Increasingly, improving sustainability outcomes is less about incremental gains in furnace design and more about maximizing throughput efficiency. Higher and more consistent utilization levels enable lower energy consumption per unit processed, improved process stability and repeatability, and reduced waste associated with inefficient batch cycles. In some cases, higher utilization has been shown to reduce carbon per component by up to 60%. In simple terms, a well-utilized process is often a more sustainable process.

Rethinking Traditional Boundaries

Achieving consistently high utilization is not always straightforward within a single manufacturing site. Demand variability, product diversity, and production scheduling can all limit the ability to fully optimize furnace loading.

As sustainability targets become more demanding, some organizations are beginning to explore how these constraints can be addressed more strategically. In particular, there is growing recognition that where heat treatment takes place can influence overall efficiency outcomes, especially when greater consistency of loading and throughput can be achieved.

In environments where demand from multiple sources can be aggregated, including across organizational boundaries, it becomes possible to operate equipment closer to optimal utilization levels on a sustained basis. This can improve energy efficiency per component while maintaining process control and quality standards.

At the same time, continued advances in process technology, such as vacuum processing and low-pressure carburizing, are enabling more efficient and repeatable outcomes, particularly when combined with modern, well-utilized infrastructure.

The Role of Data in Decision Making

As expectations around sustainability reporting increase, decisions related to thermal processing are also becoming more data driven. Manufacturers are increasingly required to understand and report the carbon footprint of individual components, not just emissions at site level. This shift is placing greater emphasis on measuring energy consumption and emissions at process level, including the impact of utilization.

Tools and methodologies aligned with recognized standards are enabling more accurate modeling of energy consumption per cycle and per component, emissions associated with different processing routes, and the comparative impact of alternative operating models. This data allows engineers and decision makers to move beyond assumptions and evaluate thermal processing strategies based on measurable environmental performance.

Balancing Control, Efficiency, and Sustainability

For decades, the benchmark of a well-run heat treatment operation was control, over equipment, processes, and supply. That principle remains important. However, the definition of control is evolving. Today, control increasingly includes visibility of process performance, confidence in quality and repeatability, and the ability to meet sustainability targets alongside production requirements. In this context, improving utilization is emerging as a key consideration. It offers a practical and measurable way to reduce energy intensity without compromising technical outcomes.

A Shift in Perspective

Sustainability in thermal processing is often framed in terms of new technologies or alternative energy sources. While these remain critical, utilization highlights a broader point. Efficiency is not just designed into equipment; it is achieved through how that equipment is used.

As manufacturers continue to navigate the complexities of decarbonization, focusing on energy per component rather than energy per cycle provides a more complete picture of performance. This shift in perspective does not prescribe a single solution. Instead, it encourages a more holistic evaluation of thermal processing, one that considers utilization, technology, data, and operational context together.

Successful Examples of High Utilization, Advanced Heat Treatment

Future heat treatment facilities must deliver the reliability, quality, and flexibility demanded by leading OEMs and their suppliers, while meeting efficiency and sustainability challenges in global markets, such as aerospace and automotive. An outsourced approach, supported by local and dedicated specialist capacity, can meet these needs.

Bodycote’s heat treatment plants in Derby and Rotherham — combining advanced heat treatment and densification services — are examples of a co-located outsourced model. The aerospace partnership behind these plants demonstrates three decades of reliable, dedicated, and flexible capacity, aligned to core customer requirements.

A key advantage is utilization. By complementing core aerospace demand with additional volumes from other clients and markets, these facilities maximize utilization, driving higher efficiency, lower cost per part, and improved sustainability performance.

Both sites operate highly utilized, fully electric furnaces powered by 100% renewable electricity, enabling zero-emission thermal processing. Alongside electrification, ongoing investment in energy efficiency continues to reduce consumption. The Derby site (opened in 1999) recently installed a closed-circuit adiabatic cooling system, replacing evaporative towers and delivering electricity savings of 73%, reducing peak load and associated emissions, and cutting water use by over 85%, while eliminating chemical dosing and cleaning.

These examples demonstrate how specialist providers can deliver both advanced technical capability and low-carbon infrastructure for modern aerospace manufacturing.

Similar approaches are emerging across the aerospace industry, as manufacturers replace legacy fossil-fuel-based heat treatment with more efficient outsourced solutions. These partnerships support ambitious Scope 1 and 2 emissions reductions while ensuring long-term access to modern, lower-carbon processing capacity operated at consistently high utilization.

From Energy Per Cycle to Energy Per Component

Thermal processing will remain an essential part of advanced manufacturing. Its energy intensity makes it a natural focus for sustainability efforts, but also a significant opportunity for improvement.

Focusing on utilization shifts the conversation from how much energy a furnace consumes to how effectively that energy is used. This highlights a more meaningful measure of performance: not energy per cycle, but energy per component.

As sustainability expectations continue to rise, engineers and manufacturing leaders are being asked not only to ensure process integrity, but to demonstrate measurable efficiency and carbon performance.

In that context, the most effective improvements may not come from new equipment alone, but from rethinking how processes are operated, optimized, and where appropriate, configured.

Because ultimately, sustainable heat treatment is not just about using less energy — it is about using energy more effectively.

About The Author:

Myles McCarthy
VP, Group Sustainability
Bodycote plc

Myles McCarthy is a senior sustainability and climate leader within Bodycote’s sustainability team, focused on driving and delivering corporate strategies that support the transition to more sustainable businesses. He has 25 years of experience working with boards and senior management of global businesses, both as an external climate advisor and as an in-house sustainability lead.

For more information: Contact Myles McCarthy at Myles.McCarthy@bodycote.com.

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Rethinking On-Site Hydrogen for Flexible Control, 2 Case Studies

/ ATMOSPHERE GENERATORS TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH, SINTERING POWDER/METAL TECHNICAL CONTENT

What if durable hydrogen production design was approached from the standpoint of optimizing data analysis and controls management? When addressed as such, onsite generation can simplify deployment, reduce upfront integration risk, and enable flexible scaling for applications ranging from backup power to industrial processing. Anya Bharadwaj, product manager at Fourier Earth, examines how two North American heat treating operations — one induction, the other sintering — have leveraged software-defined modularized hydrogen to capture these advantages.

This informative piece was first released in Heat Treat Today’s April 2026 Annual Induction Heating & Melting print edition.

In the high-stakes world of advanced manufacturing, the atmosphere inside a furnace is as critical as the temperature. For decades, manufacturers have been tethered to a legacy, delivery-based model for their hydrogen supply. This energy ecosystem is increasingly showing its age, plagued by hazardous storage conditions, supply chain shocks, and logistical costs that can balloon to 7–10x the actual production costs.

Recent changes in modular electrolyzer technology challenge the delivery-based hydrogen model by enabling on-site generation directly at industrial facilities. One such approach seeks to reimagine energy distribution and storage — when, and how it is needed most. Two case studies illustrate how intelligent, software-defined systems improve reliability, reduce logistical risk, and better align supply with real-time process demand.

Achieving Scalability with PEM Electrolyzers

This system utilizes Proton Exchange Membrane (PEM) electrolyzers to split water into hydrogen and oxygen by applying electricity across a solid polymer electrolyte membrane. Water is fed to the anode side, where oxygen is ionized into positively charged ions (protons) and negatively charged ions (electrons). The protons pass through the membrane while electrons travel through an external circuit (creating the electrical loop). The protons recombine at the cathode to form hydrogen gas.

PEM systems are well-suited for dynamic operations because they respond quickly to changes in power input, operate at relatively high current densities, and produce high-purity hydrogen without requiring a separate gas purification step.

Figure 2. Fourier electrolyzer system displayed at customer site | Image Credit: Fourier

Unlike large, monolithic MW-scale electrolyzers that are complex to integrate and difficult to optimize, PEM stacks can be designed in modular units (Figure 2). Electrolyzer efficiency does not inherently improve with size, so instead of scaling up into single massive systems, the design is scaled out — splitting capacity across many smaller modules without sacrificing performance. Modularization improves lifetime and efficiency since each stack can operate at its optimal temperature, pressure, and current density.

In this architecture, variables in hydrogen production across hundreds or thousands of stacks need to be controlled and optimized. Fourier’s software-defined energy system materialized from seeing hydrogen production as a data and controls problem first and foremost. This hardware-software feedback loop combines machine learning and modular hardware to monitor and control such variables as temperature, pressure, and density.

While on-site hydrogen generation overcomes centralized hydrogen production challenges, seamless integration requires a system that functions as a distributed, intelligent energy resource. The modular architecture is driven by advanced algorithms that optimize performance in real-time, constantly adjusting to deliver peak efficiency and reliability. For modern heat treat operations, this is a crucial step to overcome the technical and commercial barriers due to transportation challenges and volatile industrial gas pricing.

Case Study 1: The Heat Treatment Facility

Table A. Performance metrics for induction brazing

The primary objective of the first pilot deployment at an induction heat treatment facility in Southern California was to generate a supply that matched the rigorous reliability and purity requirements of their brazing process. For high value components being induction brazed, hydrogen removes surface oxides from metals, preventing oxidation and improving the quality of the heated workpiece. Any supply interruption or purity dip can compromise their integrity.

In September 2025, the first modular electrolyzer unit was deployed (Figure 1). The integration process involved:

  • Direct connectivity: The unit co-located at the site and connected directly to the existing electric panel and water supply.
  • Zero-disruption tie-in: The system integrated directly into the facility’s existing hydrogen manifold, essentially replacing the delivery truck with a continuous on-site stream.
  • Technical excellence: Over a four-week pilot, the system met stringent specs — a -70°C (-94°F) dewpoint and 60 PSI pressure — supplying hydrogen for two brazing furnaces.
Figure 1. Metal parts being loaded into furnace running on Fourier hydrogen at heat treatment facility, CA | Image Credit: Fourier

During the pilot, hydrogen quality was monitored through continuous dew point and pressure sensing, with all data aggregated into a central dashboard to track moisture levels, delivery stability, and overall system performance in real time. Dew point served as a critical indicator of gas dryness, since excess moisture would directly increase oxidation risk at high-temperature induction heating. Pressure monitoring ensured steady flow and confirmed system integrity throughout each run.

Although a formal gas chromatography was not conducted during the pilot, purity was validated through application-level outcomes. Each treated batch of metal was inspected post-processing, and clean, bright surfaces were consistently observed without scale, pitting, or discoloration. Because hydrogen acts as a reducing atmosphere, even minor deviations in moisture or composition would quickly appear as visible defects. This aligned with stable sensor data and consistent operating conditions. This real-world validation is commercially meaningful: in induction heating, surface quality directly affects downstream machining, coating adhesion, and yield. Demonstrating repeatable, oxide-free results confirms both technical robustness and economic value under actual production conditions.

The successful proof-of-concept achieved industrial-grade performance and reduced costs by more than 50% on a dollar-per-kilogram basis compared to what the client was paying under the existing hydrogen contract.

Case Study 2: Compax, Inc.

Figure 3. Furnace running on Fourier hydrogen at powder metal plant, Compax, CA | Image Credit: Fourier

For the second pilot development at Compax, Inc., a leader in powdered metal manufacturing located in Southern California, the challenge centered on sintering. Compax uses hydrogen to eliminate oxygen during the heat treating process (Figure 3). The facility faced frequent price hikes and the looming threat of supply disruptions that could halt their belt sintering furnaces, a risk the company sought to eliminate.

The pilot deployment at Compax in November 2025 further proved the scalability of the design — modular units inspired by the data center world, easily configured to specific site needs. The integration process involved:

  • Rapid deployment: Within just two days, the team fully brought the system online in Compax’s utility infrastructure.
  • Tailored performance: The system delivered a flowrate of 255 SCFH at a -40°C (-40°F) dewpoint and 10 PSI, precisely optimized for the powdered metal sintering process.
  • Operational control: According to Earl Johnson, CEO of Compax, the system “reliably produced hydrogen…without the hassle of transportation,” adding that it provided much needed “flexibility against frequent increases in industrial gas prices.”
Table B. Performance metrics for sintering

Implications for Industrial Heat Treating

Both pilots achieved a structural advantage by removing logistical constraints, proving that this type of software-enabled hydrogen generation is a viable, cost-effective solution for industrial decarbonization.

By shifting from a centralized commodity model to a distributed, intelligent energy resource, manufacturers gain more than cheaper gas; they gain independence from hydrogen delivery. As the heat treat industry faces increasing pressure to decarbonize while maintaining razor-thin margins, modular, data-driven approaches offer a practical solution, lowering local emissions and ensuring on-demand production.

About The Author:

Anya Bharadwaj
Product Manager
Fourier Earth

Anya Bharadwaj is a product manager at Fourier Earth, where she leads product strategy and go-to-market for modular hydrogen electrolyzer systems. Her work focuses on identifying new market opportunities and deploying hydrogen technologies for long-duration energy storage and industrial decarbonization. She holds an MBA from Stanford Graduate School of Business and previously worked in energy investment.

For more information: Contact Anya Bharadwaj at anya@fourier.earth.

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Ask the Heat Treat Doctor®: What is pH Really?

/ MANUFACTURING HEAT TREAT TECH, PARTS CLEANING TECHNICAL-CONTENT, QUENCHING TECHNICAL CONTENT

Ask The Heat Treat Doctor® has returned to bring sage advice to Heat Treat Today readers and to answer your questions about heat treating, brazing, sintering, and other types of thermal treatments as well as questions on metallurgy, equipment, and process-related issues. In this installment, Dan Herring discusses the science behind pH — what it really measures, and why it matters — and offers practical guidance on monitoring water quality in open and closed systems found throughout the heat treat shop.

This informative piece was first released in Heat Treat Today’s May 2026 Sustainable Heat Treat Technologies print edition.

Introduction to pH

The term “pH” is used to describe a unit of measure that indicates the degree of acidity or alkalinity of a solution. It is measured on a scale of 0 to 14 (Table A). pH is an abbreviation that stands for the “potential of hydrogen”; the “p” being the symbol for potential (or power) and “H” the symbol for hydrogen.

Table A. pH Chart (Herring 2015b)

A Slightly Deeper Dive

What most people don’t realize is that pH is a complex concept rooted in chemical equilibrium, thermodynamics, and electrochemistry. The formal definition of pH is “the negative logarithm of the hydrogen ion activity” and can be expressed mathematically by the following formula where au+ is the activity of hydrogen ions, a dimensionless quantity (Rumble 2024):

In this form, pH provides a way of expressing the degree of the activity of an acid or base in terms of its hydrogen ion activity. Acids and bases have, respectively, free hydrogen [H+] and free hydroxyl [OH−] ions. Since the relationship between hydrogen ions and hydroxyl ions in a given solution is constant for a given set of conditions, either one can determine the other. In other words, pH is really a measurement of both acidity and alkalinity, even though by definition it is a selective measurement of hydrogen ion activity.

Since pH is a logarithmic function, a change of one pH unit represents a tenfold change in hydrogen ion concentration, that is, of both the hydrogen ion and the hydroxyl ion at different pH values (Table A). Note that each decrease in pH by one pH unit means a tenfold increase in the concentration of hydrogen ions.

A Little Chemistry

In school, we learned that all substances are made up of millions of tiny atoms. These atoms combine to form molecules. In water, for example, each molecule is made up of two hydrogen (H) atoms and one oxygen (O) atom. The formula for a molecule of water is expressed by the familiar symbol H2O. That is, there are two hydrogen atoms needed for each oxygen atom to form a stable compound.

Now, the behavior of pH in aqueous systems is governed by the equilibrium of water to form positive and negative ions (so-called self-ionization), which can be expressed as:

or in the following form we more commonly think of:

Hency, at 25°C (Kw = 1.0 x 10-14), the equilibrium constant for this process is:

Then for pure water, where aH+ = a0H-, we have that aH+ = 10-7 hence pH = -log10 (10-7) = 7.00 which is neutrality at 25°C (77°F).

Finally, it is important to note that Kw is temperature-dependent: it increases with temperature, meaning neutral pH decreases slightly as temperature rises (e.g., ~6.14 at 100°C). Therefore, “neutral pH” is not always 7 — it depends on thermal conditions.

A Practical Application — Water Quality in the Heat Treat Shop

Water is used in most of our heat treat shops for a variety of purposes, perhaps less than before but still vitally important. Examples include parts washers, heat exchangers, water cooled bearings on fans and rolls, seals on pit furnace covers, water cooled jackets on continuous furnaces, water cooled jackets for quench tanks, top or side cooling chambers, inner doors and plate coils, and make up water for water systems, to name a few.

Table B. Typical Water Requirements for Open Systems (Decelles 2002)
Table C. Water Requirements for Closed Hydronic Systems (Heatlink Group 2006)

Water quality requirements are often defined differently for open systems (Table B) and closed (recirculated) systems (Table C). Open systems are typically more problematic as the issue of water quality varies. Water is often classified as “soft” or “hard” depending on its mineral content (i.e., the amount of calcium and magnesium dissolved in the water). Soft water has an ideal hardness of approximately 120 ppm (7 grains/gallon). Hard water often results in the formation of mineral deposits, which can lead to blockages in water systems (Figure 1).

Figure 1. Sludge buildup and flow blockage in the top cool of an integral quench furnace | Image Credit: The HERRING GROUP, Inc.

Furthermore, we must ensure that the water being discharged from our heat treatment operations is clean and meets EPA standards. Finally, we must be especially careful to avoid cross-contamination from other sources in the shop (e.g., polymers, quench oils, chemicals).

In Summary

Two little consonants, pH, are deceptively simple yet so profoundly important. They represent the thermodynamic state of solutions, but in reality, link microscopic interactions with real world issues. As heat treaters, our focus is to not take our water supply and water systems for granted since unexpected surprises, unwanted downtime, and expensive repairs can result. When is the last time you tested your water?

References

Herring, Daniel H. 2015a. Atmosphere Heat Treatment. Vol. 2. Southfield, MI: BNP Media.

Herring, Daniel H. 2015b. “The Importance of pH.” Industrial Heating, January.

Heatlink Group. 2006. Water Quality in Hydronic Systems. June 21, 2006. https://www.heatlink.com/sites/default/files/Info%20Sheet/L2329-Water-Quality-in-Hydronic-Systems-2006-06-21.pdf.

Decelles, P. 2002. The pH Scale. Johnson County Community College. Archived webpage. http://staff.jccc.net/pdecell/chemistry/phscale.html.

Rumble, John R., ed. 2024. CRC Handbook of Chemistry and Physics. 105th ed. Boca Raton, FL: CRC Press.

About the Author

Dan Herring
“The Heat Treat Doctor”
The HERRING GROUP, Inc.

Dan Herring has been in the industry for over 50 years and has gained vast experience in fields that include materials science, engineering, metallurgy, new product research, and many other areas. He is the author of six books and over 700 technical articles.

For more information: Contact Dan at dherring@heat-treat-doctor.com.

For more information about Dan’s books: see his page at the Heat Treat Store.

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Optimized Heat Treat Results Start with Optimized Cleaning

/ CARBURIZING TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH, PARTS CLEANING TECHNICAL-CONTENT, VACUUM FURNACES TECHNICAL CONTENT

Optimized heat treat performance starts long before parts reach the furnace. In this Technical Tuesday installment, Chris Tivnan of SAFECHEM North America Inc. highlights how SEW-EURODRIVE‘s switch to solvent-based cleaning enabled faster cycles, reliable residue removal, and consistent results.

This informative piece was first released in Heat Treat Today’s April 2026 Annual Induction Heating & Melting print edition.

In the world of industrial motion systems, precision, durability, and efficiency are non-negotiable. SEW-EURODRIVE, a manufacturer of advanced drive solutions, focuses on delivering performance-driven gearboxes and industrial drives that power everything from airport walkways and roller coasters to heavy-duty conveyors in manufacturing plants. At the heart of this capability lies the careful heat treatment of steel components, specifically gears and pinions, processed to exacting standards for strength and longevity.

From Atmospheric Carburizing to New Demands

Since 2002, SEW-EURODRIVE had relied on a well-established process: aqueous cleaning, followed by atmospheric carburizing, oil quenching, and a second aqueous cleaning process. The approach was reliable but not without limitations.

Their gas-fired furnaces demanded costly maintenance, such as re-bricking the hot zone, replacing furnace rails, and frequently tuning the burners to ensure safety. Oil quenching created a messy environment and required an additional post-quench wash. For smaller parts, the process was also highly labor-intensive. Operators had to manually build furnace loads, then shot blast parts after heat treatment. Processing several hundred thousand gears and pinions per year in this way translated into significant time and manpower.

Figure 1. Advanced robotics drive SEW-EURODRIVE’s fully automated cleaning and vacuum carburizing line — delivering higher throughput, consistency, and precision. Image Credit: ECM & SEW-EURODRIVE

SEW-EURODRIVE maintained five atmospheric furnaces on site, but to improve efficiency they envisioned a new setup: continuing to run large parts in the existing furnaces while shifting smaller, higher-volume gears and pinions to a vacuum carburizing line with robotic automation.

Why Vacuum Carburizing and Why Cleaning Matters

The ECM NANO vacuum carburizing system, designed for small batch sizes, allowed SEW-EURODRIVE to integrate robotic loading and unloading, a crucial step toward automation. Vacuum carburizing also offered tighter process control, reduced distortion, and more consistent results than atmospheric methods.

However, vacuum carburizing is unforgiving when it comes to cleanliness. Unlike atmospheric furnaces, which can tolerate some surface contamination, vacuum furnaces demand perfectly clean parts. Any residue from machining oils, coolants, or metal shavings risks compromising part quality and furnace integrity.

This is where cleaning — often treated as a secondary or preparatory step — became the cornerstone of SEW-EURODRIVE’s process reengineering. The HEMO hybrid cleaning machine, capable of running both aqueous and solvent programs, was selected to provide maximum flexibility. The system runs on the modified alcohol solvent DOWCLENE™ 1601.

Overcoming Initial Concerns

For a company committed to environmental responsibility, introducing a solvent-based process was not taken lightly. Concerns about waste disposal, flammability, and worker exposure were thoroughly evaluated. However, the hermetically sealed HEMO cleaning system, designed for safe solvent handling and minimal emissions, provided the reassurance the Environmental Health and Safety (EHS) team required.

Beyond the demands of vacuum carburizing itself, another decisive factor for solvent cleaning is the use of carbon fiber composite (CFC) fixtures in the cleaning and heat treat line. Lightweight yet highly durable, these fixtures make automated handling of smaller batch sizes possible. However, their porous structure tends to absorb liquids during cleaning. Any residual moisture or oils can later release in the furnace, risking damage to the hot zone and compromising part quality.

Compared with aqueous cleaning, solvent cleaning evaporates completely and removes absorbed residues far more effectively, leaving both parts and fixtures perfectly dry. In this way, solvent cleaning makes automation with CFC not only feasible but reliable. Multiple test cycles, conducted both at HEMO’s and ECM’s facilities, confirmed the performance: only solvent cleaning reliably removed the oils and coolants that could otherwise lead to furnace fouling or part discoloration.

A Technical and Operational Leap Forward

By March 2025, the fully integrated cleaning and vacuum carburizing line was in full production. The new process — solvent cleaning, vacuum carburizing, gas quenching, and tempering — represented a dramatic leap forward, both technically and operationally.

Figure 2. Full integration of HEMO cleaning and ECM vacuum technology enables a streamlined, automated workflow. | Image Credit: ECM & SEW-EURODRIVE

Parts now exit the furnace bright and clean, with no spotting or discoloration. The smaller batch sizes of the vacuum furnace system enable robotic loading, helping to achieve a streamlined, automated heat treat flow, especially critical for high-volume parts.

Manual processes once needed to build and break down furnace loads, as well as to shot blast parts post-treatment, have been fully eliminated for small components. This shift has not only freed up significant labor hours for larger parts that still require traditional handling but has also eliminated roughly $6,000 per month in consumable abrasive costs.

“In the past, it would take us two weeks to process an order of 25,000 gears and 25,000 pinions through the manual steps. That manpower is no longer needed on a very large section of our product family,” explained Chris Rollins, SEW-EURODRIVE’s Heat Treat Supervisor.

The hybrid cleaning system, equipped with aqueous and solvent cleaning technologies, was selected to provide maximum flexibility in removing different types of machining soils. This versatility ensured that the system could adapt to any future cleaning requirements. In practice, after extensive testing, SEW-EURODRIVE determined that solvent-only cycles best matched the needs of their vacuum carburizing line, offering the shortest cycle times and most consistent cleaning results.

While hybrid programs run in about 30 minutes and aqueous cycles in around 50 minutes, solvent-only cycles achieve the same high cleanliness in just 18 to 22 minutes — fast enough to keep pace with furnace loading and optimize overall throughput.

Gas quenching has also replaced oil quenching, eliminating the need for a second aqueous wash and the associated challenges of soap concentrations, rinses, and tank maintenance. Beyond weekly solvent checks and routine discharges, maintenance requirements for the cleaning machine remain low.

“With aqueous cleaning, it’s always a delicate balance to get the right amount of soap for cleaning without leaving spots,” explained Rollins. “With solvent cleaning, we don’t see spotting, rust, or any contaminants. The vacuum process also helps reduce distortion, so we have more consistent parts.”

Cleaner Start, Cleaner Finish

Optimizing heat treat results meant looking beyond the furnace for SEW-EURODRIVE. With vacuum carburizing, cleanliness is no longer optional — it’s critical. The integration of the hybrid cleaning technology unlocked the full advantages of the vacuum carburizing furnace system: automation, speed, quality, and consistency.

This process reengineering experience demonstrated that heat treat success starts far earlier, in the cleaning phase, and that true optimization comes from understanding how each part of the system supports the others. In this case, the cleaner the start, the cleaner the finish. “The new system has made us faster, leaner, and more confident in every part that leaves the line. Solvent cleaning wasn’t just a switch — it was the key to making vacuum carburizing work,” concluded Rollins.

About The Author:

Chris Tivnan
Sales Manager
SAFECHEM North America Inc.

With two decades of experience in the chemical industry, Chris Tivnan of SAFECHEM North America Inc. counsels manufacturers on the right choice of cleaning agent and their parts cleaning operation. He also manages relationships with regional distributors as well as local OEMs/OEAs.

For more information: Contact Chris Tivnan at c.tivnan@safechem.com.

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Acero Descarburizado: Crítico para el Endurecimiento por inducción de Cuchillas Rotativas

/ ANNEALING TECHNICAL CONTENT, INDUCTION HEATING EQUIPMENT TECHNICAL CONTENT, INDUCTION HEATING TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH

Para las operaciones de tratamiento térmico internas (in house), el objetivo principal es producir un producto confiable con un desempeño consistente en servicio. Sin embargo, la cadena de suministro y los procesos especializados pueden generar factores que comprometen la consistencia. En este artículo, Heat Treat Today destaca la importancia de contar con material base consistente para el tratamiento térmico por inducción interno de National Steel Rule, y cómo se puede implementar el proceso esencial de descarburización controlada en la planta proveedora de acero.

Este artículo informativo se publicó por primera vez en Heat Treat Today’s April 2026 Annual Induction Heating & Melting print edition. Traducido por Ana Laura Hernández Sustaita.

Si tiene comentarios o preguntas sobre este artículo, háganoslo saber en: editor@heattreattoday.com.

To read this article in English, click here.

Introducción: Regla de Acero que se Dobla

La empresa National Steel Rule produce reglas de corte rotativas para la industria del cartón corrugado. Ubicada en Linden, Nueva Jersey, la empresa suministra productos a las industrias de troquelado a nivel mundial. La compañía ha establecido altos estándares de abastecimiento, investigación y pruebas de material para sus reglas de corte, además de contar con un completo laboratorio con equipos de troquelado rotativo y plano.

Su regla de acero se adquiere de una planta proveedora de acero que realiza una descarburización controlada en todo el material. Cuando National recibe el material, procesa el acero para generar los dientes, empleando endurecimiento por inducción como parte del proceso (ver la imagen principal al inicio de este artículo). La regla de corte terminada se vende posteriormente a fabricantes de troqueles de regla de acero, quienes montan estas cuchillas junto con una goma de expulsión sobre tableros de madera cortados con láser. El fabricante debe asegurarse de que las cuchillas de las reglas estén libres de defectos, ya que incluso grietas microscópicas se abrirán durante el troquelado.


Figura 1. Regla de acero doblada de diámetro pequeño | Crédito de la imagen: National Steel Rule

Las cuchillas rotativas y otros productos de National dependen de la compra de acero descarburizado. “La flexibilidad y la conformabilidad son fundamentales”, afirma Ed Mucci, presidente de la empresa, y Alexander Heucke, ingeniero en jefe. La regla de corte debe doblarse para formar una cuchilla circular; durante el servicio, la cuchilla rota para cortar el material corrugado. La geometría de la curvatura puede ser extrema, llegando a doblarse hasta un diámetro interior de 7 pulgadas. Por lo tanto, la compra de acero descarburizado es crítica para el negocio del fabricante. Actualmente, National obtiene el material a nivel internacional. Mucci explica: “Los fabricantes no utilizan grandes cantidades de acero descarburizado, lo que dificulta su abastecimiento, al menos a nivel nacional”.

El material para las reglas rotativas suele ser acero al carbono C36 (SAE 1036) a C50 (SAE 1050) con un rango de dureza de 32–34 HRC. Mucci y Heucke señalan que el acero que utilizan presenta una capa de descarburización total de 0.0005” de profundidad, con una descarburización parcial adicional de al menos 0.0005”–0.00075”. Esto garantiza que cuando una regla se dobla, la superficie se elongue en lugar de agrietarse. Doblar la regla es, en sí mismo, una prueba para comprobar si se ha descarburado correctamente, y las pruebas metalúrgicas sirven como verificación de control de calidad para garantizar que los proveedores estén produciendo los niveles adecuados de descarburización.

Endurecimiento Preciso por Inducción de los Dientes

Si bien el doblado es esencial para formar la curvatura apropiada, los dientes deben ser resistentes al desgaste y la rotura. La regla de corte rotativa de National tiene una expectativa de desempeño de al menos 750,000 impresiones en papel, que es en sí mismo un material altamente abrasivo. Para lograrlo, las operaciones de tratamiento térmico internas endurecen por inducción el borde de la regla, garantizando una larga vida útil del troquel.

Existen dos métodos usados para endurecer los dientes. El método principal es maquinar el perfil de la tira de acero y posteriormente endurecer por inducción el borde. Posteriormente los dientes son rectificados. “Esto nos da un mejor control sobre la profundidad de endurecimiento”, comenta Mucci y Heuke. El segundo método consiste en endurecer por inducción después de rectificar los dientes. “Debemos asegurarnos de que el endurecimiento de los dientes no sea muy profundo, ya que esto puede afectar la capacidad de doblado”. El endurecimiento por inducción implica ciclos muy cortos, y por lo tanto requiere un control minucioso del proceso para garantizar resultados consistentes. Entre los métodos de control del proceso se utilizan crayones indicadores de temperatura, que se funden a una temperatura específica. También se realizan pruebas de dureza.


Figura 2. Detalle de la capa descarburizada | Crédito de la imagen: National Steel Rule

Revisitando la Descarburización

“Generalmente se intenta prevenir la descarburización o incluso agregar carbono a la superficie”, comenta Mark Hemsath, consultor ejecutivo en WINGENS CONSULTANTS y reconocido experto e innovador en la industria del tratamiento térmico. “La descarburización a menudo ocurre accidentalmente en sistemas de recocido mal diseñados, especialmente en hornos de tratamiento continuo.”


Figura 3. Diagrama de Ellingham que muestra la relación hidrógeno-vapor de agua, clave para una descarburización controlada exitosa.

Figura 4. Horno típico de recocido tipo campana. | Crédito de la imagen: RAD-CON

El oxígeno en forma de aire o de vapor es la clave del proceso de descarburización. Menor porcentaje de carbono en la superficie indica un acero más blando y maleable, y si bien el arte de un proceso de descarburización controlada es bien conocido, puede resultar un desafío. El proceso de descarburización suele realizarse por debajo de 1500°F (815°C). “El método preferido es usar vapor de agua o vapor como fuente de oxígeno”, señala Hemsath. Esto se basa en la estabilidad de la relación hidrógeno-vapor de agua (H2/H2O) derivada del diagrama de Ellingham. Estas relaciones H2/H2O indican las propiedades no oxidantes de la mezcla gaseosa, lo que permite que actúe como agente reductor de carbono en la atmósfera del horno. La mayoría de las empresas fabricantes de hornos pueden proporcionar el equipo necesario y personalizar las dimensiones para hacerlos adecuados para este proceso especial. Estos hornos suelen ser de tipo campana o tipo foso con retorta.

Dos Métodos para Controlar la Descarburización

Existen dos formas de realizar intencionalmente un proceso de descarburización. La primera consiste en descarburar todo el producto. En este método, la descarburización se aplica de manera uniforme en toda la superficie de la lámina o bobina. “Este acero laminado en frío generalmente con menor contenido de carbono, se utiliza en electrodomésticos que requieren una buena adherencia del esmalte”, explica Hemsath. Empresas como U.S. Steel y AK Steel (ahora parte de Cleveland-Cliffs) han utilizado esta forma de descarburización controlada.

Otra forma es la descarburización selectiva en la superficie. Hemsath explica: “Si la descarburización solo se requiere en los bordes, se podrían mantener las bobinas enrolladas firmemente, por lo tanto, la descarburización afectaría principalmente a los bordes. Se produciría una pérdida de carbono que disminuiría hacia el centro de las superficies enrolladas”.

Conclusión

“El acero descarburizado tiene mucha demanda, ya que la mayoría de las industrias buscan endurecer y templar los aceros que utilizan”, indica Mucci. De hecho, la prevención de la descarburización del acero es más común y suele destacar en ferias industriales, presentaciones técnicas y publicaciones de procesamiento térmico. Sin embargo, existen productos que dependen de la descarburización intencional para funcionar correctamente.

La descarburización controlada en la planta proveedora de acero presenta desafíos, en parte porque lograr una descarburización exitosa y consistente no suele ser económicamente viable para el mercado norteamericano de tratamiento térmico. Estos desafíos abarcan problemas de acceso regional, acceso a nichos de mercado, necesidades de selección de equipos y ejecución de procesos técnicos.

La experiencia de National destaca los desafíos que enfrentan las plantas proveedoras de acero de América del Norte para proveer a las empresas de tratamiento térmico interno, acero descarburizado de forma fiable y bien controlada que mantenga su vida útil.


Agradecimientos: Heat Treat Today agradece a Dan Herring, The Heat Treat Doctor®, The HERRING GROUP, Inc., quien fue fundamental en el desarrollo de este artículo.


Para más información: Contacte con Heat Treat Today’s Editorial Team en editor@heattreattoday.com.

La imagen principal: Regla rotativa RP8 con borde endurecido | Crédito de la imagen: National Steel Rule

Acero Descarburizado: Crítico para el Endurecimiento por inducción de Cuchillas Rotativas Read More »

Decarburized Steel Critical for Induction Hardening Rotary Blades

/ ANNEALING TECHNICAL CONTENT, INDUCTION HEATING EQUIPMENT TECHNICAL CONTENT, INDUCTION HEATING TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH

For in-house heat treat operations, the number one goal is to produce a reliable product with consistent in-service performance. Yet supply chain and specialized processes can cause consistency stressors. In this article, Heat Treat Today underlines the importance of consistent feedstock for in-house induction heat treater, National Steel Rule, and how the essential mill process of controlled decarburization can be actualized.

This informative piece was first released in Heat Treat Today’s April 2026 Annual Induction Heating & Melting print edition.

If you have any comments or queries, on this article, let us know at editor@heattreattoday.com.

Para leer el artículo en español, haga clic aquí.

Introduction: Steel Rule that Bends

National Steel Rule manufactures rotary cutting rule for the corrugated box industry. Located in Linden, New Jersey, the company supplies products to the die making and die cutting industries globally. They have established a high standard of sourcing, researching, and testing material for their rule, in addition to a complete testing laboratory with both rotary and flat die cutting equipment.

Their steel rule is purchased from a mill that performs a controlled decarburization on the entire feedstock. When National receives the steel feedstock, they work the steel to create teeth, employing induction hardening as part of the process. The finished cutting rule is then sold to steel rule die makers who mount these blades and an ejection rubber on laser cut wooden boards. The manufacturer must ensure their rule blades are sound, as even microscopic cracks will open during the die cutting process.

Figure 1. Small diameter bent rule | Image Credit: National Steel Rule

National’s rotary blades and other products rely on purchasing decarburized steel. “Flexibility and formability are paramount,” states Ed Mucci, president of the company, and Alexander Heucke, chief engineer. Cutting rule must be bent to form a circular blade; in service, that blade rotates to cut into the corrugated material. The curve geometry can be extreme, often bending up to a 7-inch interior diameter. As such, the purchase of decarburized steel is critical for the manufacturer’s business. At present, National sources the material internationally. Mucci explains, “Manufacturers aren’t using large quantities of decarburized steel, making it challenging to source, at least domestically.”

Rotary rule feedstock typically involves C36 (SAE 1036) to C50 (SAE 1050) carbon steel with a hardness range of 32–34 HRC. Mucci and Heucke note that their steel of choice has a total decarburization layer to a depth of 0.0005” depth, with partial decarburization of at least another 0.0005–0.00075”. This ensures that when the rule is bent, the surface stretches versus cracks. Bending the rule is itself a test of whether it has been properly decarburized, with metallurgical testing serving as a quality control verification that suppliers are producing the appropriate decarburization levels.

Precise Induction Hardening Teeth

While bending is essential to forming the appropriate curve, the teeth must be resistant to wear and breakage. National’s rotary cutting rule has performance expectations of at least 750,000 impressions on paper, itself a highly abrasive material. To do this, their in-house heat treat operations induction harden the edge of the rule to ensure a long die life.

There are two methods used to harden the teeth. The primary method is to shave a profile into the strip steel and then induction harden this edge. Serrated teeth are then ground in. “This gives us better control of hardening depth,” according to Mucci and Heuke. The second method is to induction harden after the serrated teeth are ground in. “We have to make sure we don’t harden the teeth too deeply, or we can affect the bendability.”

Induction hardening involves short cycles, and as such requires careful process control to guarantee consistent results; temperature-indicating crayons that melt at a specific temperature are used as one of the process control methods. Hardness testing is performed as well.

Screenshot

Decarburization Revisited

“Usually, one tries to prevent decarburization or even add carbon,” states Mark Hemsath, executive consultant at WINGENS CONSULTANTS and longtime expert and innovator in the thermal processing industry. “Decarb often occurs by accident in poorly designed annealing systems, especially in continuous-type furnaces.”

Figure 3. Ellingham Diagram depicting that hydrogen-to-water vapor relationship, the key to a successful, controlled decarburization.
Figure 4. Typical bell-annealing furnace | Image Credit: RAD-CON

Oxygen, in the form of air or water vapor, is key to the decarburizing process. Less carbon on the surface means a softer, more malleable steel, and while the art of a controlled decarburization process is well known, it can be challenging. Decarburization is a process usually performed below 1500°F. “The preferred method is to use water vapor or steam as a source of the oxygen,” notes Hemsath, pointing to the stability of hydrogen-to-water vapor (H₂/H₂O ratio) derived from the Ellingham diagram. These H₂/H₂O ratios indicate the non-oxidizing qualities of the gaseous mixture, which will allow it to be the carbon reducing agent in the atmosphere. Most furnace companies can provide the necessary equipment and customize size specifications to make it suitable for this special process, and these furnaces are typically retort-based bell or pit type.

Two Methods to Control the Decarb

There are two ways that a decarburization process can be intentionally completed. The first is decarburizing the entire product. In this method, even decarburization is applied to the entire coil sheet surface. “This cold rolled steel, typically with lower carbon, is used for appliances that need enamel adhesion,” Hemsath explained, noting U.S. Steel and AK Steel, now a part of Cleveland-Cliffs, have used this form of controlled decarburization.

Another form of decarburization is selective surface decarburization. Hemsath shared, “If selective decarburizing is required only on the edges, then you could keep the coils tightly wound and the decarburization would affect mainly the coil edges. There would be ingress of carbon loss, reducing towards the center of the wound coil surfaces.”

Conclusion

“Decarburized steel just isn’t in high demand,” according to Mucci, as “most industries are looking to harden and temper the steels they use.” In fact, preventative steel decarburization is more typical and often emphasized in trade shows, technical presentations, and in thermal processing publications. Yet there are products that rely on intentional decarburization to be successful.

Controlled decarburization at the mill brings challenges, in part because successful, consistent decarburization is not often cost effective for the North American thermal processing market. These challenges encompass regional access issues, niche market access, equipment selection needs, and technical process execution.

National’s experience underlines the challenges North American mills face in providing local, in-house heat treaters with reliably, well-controlled decarburized steel that will maintain service life.

Acknowledgements: Heat Treat Todayextends thanks to Dan Herring, The Heat Treat Doctor® at The HERRING GROUP, Inc., who was instrumental in the development of this article.

For more information: Contact Heat Treat Today’s Editorial Team at editor@heattreattoday.com.

Main image: RP8 rotary rule edge hardened | Image Credit: National Steel Rule

Decarburized Steel Critical for Induction Hardening Rotary Blades Read More »

Consider Carbon Footprint in Material Selection Strategy

/ CONTROLS TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH

When carbon-footprint assessment happens during material selection for CAE simulations and product design, the result is more informed and sustainable decisions. In this Technical Tuesday installment, Mariagrazia Vottari, chief technical officer at Total Materia AG, shows how informed material choices can identify lower-impact alternatives without compromising structural, mechanical, or physical requirements.

This informative piece was first released in Heat Treat Today’s May 2026 Sustainable Heat Treat Technologies print edition.

Introduction

Governments and industries worldwide are setting increasingly ambitious targets to reduce greenhouse gas (GHG) emissions and strengthen environmental responsibility across supply chains. New sustainability frameworks, mandatory reporting requirements, and carbon-pricing mechanisms are accelerating the shift toward low-carbon production, including stricter expectations for transparent environmental data and lifecycle assessments.

Consequently, global supply chains must adapt quickly, integrating sustainability considerations from the earliest stages of product design through manufacturing, distribution, and end-of-life management. Environmental performance, traceability, and responsible material selection are becoming essential elements of modern engineering and product-development strategies.

Materials themselves represent a major share of global GHG emissions, increasing from 5 to 11 global net anthropogenic GHG emissions (GtCO₂-eq) between 1995 and 2015, and rising from 15% to 23% of global totals. For most products, materials dominate the carbon footprint until manufacturing is complete.

Accurate material selection in early product design and CAE (computer aided engineering) simulations is critical. Beyond traditional factors, such as mechanical performance and cost, engineers must now consider carbon footprint, environmental impact, lightweighting, regulatory compliance, and supply chain optimization to reduce overall emissions.

Therefore, sustainable product design will incorporate Life Cycle Assessment (LCA) of materials using selected indicator(s) providing environmental impact to materials selection. For example, in the automotive industry, ranking (c) is often calculated as c = 0.4 × mass + 0.2 × cost + 0.4 × CF.

Other more complex decision-making models for materials selection have been proposed. This exemplifies the need for reliable and simplified calculation of carbon footprint (CF) value for thousands of diversified structural materials, from carbon and stainless steel to special alloys, nonferrous metals, and polymers, considering their manufacturing routes, processing, finish, and transport. A full LCA study is demanding in terms of both data collection efforts and user expertise requirements, while streamlined LCA often uses generic data related to the materials production, energy used for their processing, and transportation. Typically, streamlined LCA uses only a fraction of the inputs to estimate carbon footprint compared to the full LCA inventory. This article presents recent developments designed to help engineers in the CAE simulation field to cope with these challenges.

Streamlined LCA Methodology

Figure 1. LCIA assessment approach | Image Credit: Total Materia

There are numerous simplification approaches in LCA; the following describes the approach that combines the composition of alloys with carbon footprint values of base metal and alloying elements production. The LCA tool described in the current study (Figure 1) can cover a variety of ferrous and non-ferrous alloys due to the use of:

  • Chemical compositions from a large database containing structural material properties, which comprises more than 500,000 materials; and
  • Country, manufacturing route, processing, and transport-specific life cycle inventory (LCI) collected from Ecoinvent v3.10, along with relevant data from scientific articles.

Goal, Scope, Functional Unit and System Boundaries

The aim of this LCA is to quantify the impact of steel and various non-ferrous alloys (Al, Cu, Mg, Ni, and Ti based) according to ISO 14040 standards, analyzing the influence of the composition on the carbon footprint.

The functional unit has been defined as 1 kg of produced material, considering the country of manufacturing and processing as well as transport to the buyer’s gate.

The scope of this study is to estimate the environmental impact of the production and the transport of materials (cradle to gate), accounting for raw materials extraction, manufacturing, and processing.

Inventory Data and Impact Category

Ecoinvent’s Life Cycle Inventory Assessment (LCIA) datasets were used where possible, including:

  • Base metals
  • Alloying elements, utilized in the manufacturing calculation through chemical composition weighting
  • Processing, quantified in kg CO₂-eq per kg of material, per kg of removed material, or per m², varying with the type of processing
  • The energy mix, allowing country-specific calculation
  • Transport, covering a wide range of routes

Calculations are based on the cut-off system model, the IPCC 2021 no LT LCIA method, and the climate change Global Warming Potential (GWP100) indicator.

Additional sources were used from scientific literature for data not available in Ecoinvent. The calculation scope expanded with:

  • Scrap content adjustment manufacturing contributions from various countries/regions
  • Contributions from different manufacturing routes
  • Various processes in different countries/regions

For intensive electricity-consuming processes, such as hot rolling, cold rolling, and stamping, electricity consumption data (measured in MJ/kg or kWh/kg) has been collected. This data, combined with the energy mix information from Ecoinvent, contributes to the final calculation.

Figure 2. System boundaries | Image Credit: Total Materia

The final CO₂-eq score is the cumulative sum of contributions from material production (manufacturing), processing, and transport as shown in Figure 2, illustrating the system boundaries considered in the study.

Analysis CF Results

In this work, six different alloys that are commonly used have been selected for the carbon footprint analysis. The chemical composition of alloys is defined by specific standard, while details on studied alloys production are presented in Figure 3.

Figure 3. Result of CF calculation for selected alloys | Image Credit: Total Materia

After specifying details on manufacturing (country, method, and recycled content), processing (country and processing applied), and transport (type and distance), the values of carbon footprint are determined for each alloy (Figure 3), providing the contribution of each stage of analysis.

The lowest environmental impact of all studied alloys was steel 1.4301 with a value of 2.5 kg CO₂-eq/kg. This is because a manufacturing route for the 1.4301 alloy was EAF (electric arc furnace) with 100% recycled content, where electricity is used to melt scrap steel and produce new steel, in contrast to BF-BOF (blast furnace-basic oxygen furnace) where extraction of iron ore is needed and relies heavily on coal or coke as a fuel source for the blast furnace, which emits significant amounts of CO₂ during combustion. Although numerous factors or variables play a role in determining the environmental impacts of metal production, one of the most significant parameters is recycled content.

Titanium alloy has the highest environmental impact of all studied alloys, emitting up to 47.3 kg CO₂-eq/kg of material. Ti-6Al-4V alloy was selected for this study even though it is very expensive and has a high energy consumption of production in the long and demanding Kroll process, because it is one of the most popular joint implant materials due to its biocompatibility, low density, and strength.

Although Al, Cu, and Fe-Ni-based alloys have similar CF values (4.7 to 8 kg CO₂-eq/kg), in the case of aluminum and copper alloys, the most significant contribution comes from the processing of those alloys (52 to 68%), unlike Incoloy in which processing contributes a modest 0.72%. The CF value for Incoloy 800 is three times greater than 1.4301 alloy. The high environmental impact of Incoloy 800 is mainly caused by nickel content (max. 10% in 1.4301 alloy, while max. 35% in Incoloy 800) and very high carbon footprint values for nickel itself. This is proof of why chemical composition cannot be neglected.

The effect of transportation is very small, only contributing up to 3.6% for selected transport parameters. However, it can have much higher relative contribution for low-impact alloys, especially over long distances. In Figure 4, the effect of different transport types shows that the selection of air transport can double the carbon footprint value of the material compared to sea transport (for the same manufacturing and processing parameters).

Figure 4. Effect of different transport types | Image Credit: Total Materia
Figure 5. Detailed contribution analysis for 1.4301 steel | Image Credit: Total Materia

Further contribution analysis can be made for each alloy given the detailed contribution for manufacturing and each processing step, as well as transportation type, as shown in Figure 5 for the 1.4301 steel. Results show that deep drawing increases carbon footprint with a factor of 5 in comparison with hot rolling. This suggests that such processes should be performed on locations having energy supplied from renewable sources.

Material Selection, Looking for a Greener Alternative

Besides identifying more environmentally sustainable manufacturing processes such as alternative production routes, higher scrap content, different locations, processing with lower energy demand, and greener transportation options, another approach to reducing the carbon footprint is to identify alternative materials with different chemical compositions but similar mechanical and physical properties.

Although the selection of alternative materials must consider various factors related to the availability, supply chain, etc., from the environmental point of view, the decision can be facilitated by using a proper cross-reference system that simultaneously suggests alternatives based on various criteria. There are two scenarios for material selection:

  1. In the early design phase when the material is still not selected and when certain mechanical, physical, compliance and sustainability requirements should be fulfilled.
  2. When a certain material already in use should be replaced with a greener alternative but maintain the same characteristics.

In the first case, material-selection tools like the Total Materia Optimizer can be used to support engineers in comparing and ranking materials based on multiple technical and regulatory criteria. This tool can evaluate thousands of potential candidates simultaneously and filter them according to user-defined parameters, such as mechanical performance, chemical composition, cost, regulatory status, or regional availability as shown in Figure 6.

Figure 6. Results of multicriteria search | Image Credit: Total Materia
Figure 7. Alternatives to 1.4301 steel based on cross references | Image Credit: Total Materia

In the second case, when the material is already in use, finding an alternative material with a lower CF value is possible in a material-selection tool’s carbon footprint module through the cross-reference option. The system offers alternatives based on various criteria. As an example for this case, 1.4301 alloy is used with all set-up parameters from Figures 4 and 6 (with CF value of 2.528 kg CO₂-eq/kg). The analysis shown in Figure 7 suggests 921 alternative materials ordered by CF value in ascending order. In this view, a user can add additional columns with mechanical and physical properties to ensure that the material also fulfills the required characteristics. In this example, material NSSC 2120 meets the required mechanical and physical criteria, and the CF value is reduced from 2.5 to 2.2 kg CO₂-eq/kg (which is a reduction of 12%) compared to the initially selected material 1.4301.

Conclusions

This approach for assessing the environmental impact of ferrous and non-ferrous alloys based on material composition and processing routes has been illustrated through a carbon footprint evaluation. It enables engineers to compare materials not only by cost and performance but also by their carbon intensity, supporting more informed and sustainable selection decisions. The method also helps identify greener manufacturing options, such as alternative routes, higher recycled content, lower-energy processing, or reduced-impact transport, early in product design while maintaining quality and performance.

Future improvements include expanding datasets to cover additional processing steps, incorporating more specific manufacturing routes — especially for non-ferrous alloys — and increasing regional coverage to reflect local energy mixes. These enhancements will further refine emission factors and improve the accuracy of carbon-footprint assessments.

References

European Green Deal. 2019. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=COM:2019:640:FIN (accessed November 2025).

Federal Climate Protection Act. n.d. https://www.bmuv.de/gesetz/bundes-klimaschutzgesetz (accessed November 2025).

Corporate Sustainability Reporting Directive (CSRD). 2022. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32022L2464 (accessed November 2025).

Carbon Border Adjustment Mechanism (CBAM). 2023. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32023R0956 (accessed November 2025).

Hertwich, E. G. 2021. “Increased Carbon Footprint of Materials Production Driven by Rise in Investments.” Nature Geoscience 14: 151–155.

Ermolaeva, N. S., M. B. G. Castro, and P. V. Kandachar. 2004. “Materials Selection for an Automotive Structure by Integrating Structural Optimization with Environmental Impact Assessment.” Materials and Design 25: 689–698.

Ic, Y. T., B. M. Hamzaoğlu, and M. Yurdakul. 2024. “A Robust Aluminum Material Selection Process in the Aviation Industry: A Linear Discrete System Stability Test Perspective for Fuzzy Multicriteria Decision-Making.” Arabian Journal for Science and Engineering.

Tasala Gradin, K. 2020. Simplified Life Cycle Assessment Approaches and Potential Impact Shifts. Doctoral thesis, KTH Royal Institute of Technology.

Treloar, G., P. Love, and J. Smith. 1999. “Streamlined Life Cycle Assessment: A Method for Considering Environmental Impact of Road Construction.” In Proceedings of the 15th Annual ARCOM Conference, edited by W. Hughes, 753–762. Liverpool John Moores University. Association of Researchers in Construction Management.

Gómez, P., D. Elduque, J. Sarasa, C. Pina, and C. Javierre. 2016. “Influence of Composition on the Environmental Impact of a Cast Aluminum Alloy.” Materials 9: 412.

Gutiérrez, I. G., D. Elduque, C. Pina, R. Tobajas, and C. Javierre. 2020. “Influence of the Composition on the Environmental Impact of a Casting Magnesium Alloy.” Sustainability 12: 10494.

Gutiérrez, I. G., D. Elduque, C. Pina, R. Tobajas, and C. Javierre. 2021. “Excel Tool to Assess the Environmental Impact of Steels Based on the Composition.” In 9th International Workshop on Simulation for Energy, Sustainable Development & Environment. ISSN 2724-0061.

Total Materia AG. n.d. https://www.totalmateria.com (accessed November 2025).

Wernet, G., C. Bauer, B. Steubing, J. Reinhard, E. Moreno-Ruiz, and B. Weidema. 2016. “The Ecoinvent Database Version 3 (Part I): Overview and Methodology.” The International Journal of Life Cycle Assessment 21 (9): 1218–1230. (Version 3.10, 2023).

International Organization for Standardization (ISO). 2006. Environmental Management—Life Cycle Assessment—Principles and Framework (ISO 14040).

Broadbent, C. 2016. “Steel’s Recyclability: Demonstrating the Benefits of Recycling Steel to Achieve a Circular Economy.” The International Journal of Life Cycle Assessment 21: 1658–1665.

Norgate, T. E., S. Jahanshahi, and W. J. Rankin. 2007. “Assessing the Environmental Impact of Metal Production Processes.” Journal of Cleaner Production 15: 838–848.

Nilsson, A. E., M. M. Aragonés, F. A. Torralvo, V. Dunon, H. Angel, K. Komnitsas, and K. Willquist. 2017. “A Review of the Carbon Footprint of Cu and Zn Production from Primary and Secondary Sources.” Minerals 7: 168.

About The Author:

Mariagrazia Vottari
Chief Technical Officer
Total Materia AG

Mariagrazia Vottari is the chief technical officer at Total Materia AG, leading the Engineering Department and overseeing data content development and material intelligence initiatives. She has a background in mechanical engineering and nearly 20 years of experience in the industry, with a strong focus on materials engineering, data processing, and digital solutions for the manufacturing industry.

For more information: Contact Mariagrazia Vottari at m.vottari@totalmateria.com.

Consider Carbon Footprint in Material Selection Strategy Read More »

Answers in the Atmosphere: Hydrogen Part 1 — Powerful Reducing Properties, High Thermal Conductivity

/ ATMOSPHERE GENERATORS TECHNICAL CONTENT, BULK GASES & SYSTEMS TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH, OP-ED, SINTERING POWDER/METAL TECHNICAL CONTENT

In this installment of Answers in the Atmosphere, David (Dave) Wolff, an independent expert focusing on industrial atmospheres for heat treat applications, examines the powerful reducing properties and high thermal conductivity that make hydrogen a critical atmosphere in metal thermal processing.

This informative piece on hydrogen’s role in sintering, annealing, and surface protection — including how it is sourced, how it behaves inside the furnace, and how operations can safely manage this flammable atmosphere under NFPA 86 — was first released in Heat Treat Today’s April 2026 Annual Induction Heating & Melting print edition.

Hydrogen is widely used in metal thermal processing for sintering of powdered metal fabrication technologies and for heat treatment (e.g., annealing, brazing) of bulk metal manufactured components. This column draws heavily from an interview the author had with Stephen Feldbauer Ph.D., director of Research & Development at Abbott Furnace. Abbott Furnace is a leading furnace manufacturer for continuous furnaces and furnace controls. As R&D Director, Steve leads Abbott’s work in pioneering furnace advances with a special focus on debinding and sintering.

Why Hydrogen?

Stephen Feldbauer, PhD
Director of Research & Development
Abbott Furnace

Hydrogen provides two desirable characteristics to heat treaters: very high chemical reducing potential and the highest thermal conductivity of any gas. The high reducing potential enables hydrogen to convert heated metal oxide coatings to pure metals. This is extremely helpful for successful sintering of powder metallurgical parts. Superior thermal conductivity enables rapid part heat up and cool down. Compared with either vacuum or inert gas atmospheres, hydrogen enables much faster throughput and achieves shorter furnace cycles.

Hydrogen-containing atmospheres are required to successfully sinter most iron-based metal parts, whether manufactured by powder metallurgy (PM), metal injection molding (MIM), or binder-jet metal additive manufacturing techniques. As-received, the iron-containing metal powders used for these advanced fabrication techniques are covered with an iron-oxide coating, making it virtually impossible to successfully sinter the particles together under reasonable temperature conditions. Reducing the oxide coating enables successful sintering.

Hydrogen-based atmospheres used with a tube or strand furnace are the primary surface protective technology used for drawn components (e.g., wire, tubing, and profiles). Hydrogen simultaneously protects the part surface from oxidation and allows metal to anneal, which softens it and restores toughness after it has been hardened by the drawing process.

Sourcing Hydrogen

Because of its high reactivity, hydrogen is almost never found in nature as a pure gas (H2). Instead, it is generally found as a component in a compound like water (H2O) or a hydrocarbon gas or liquid, such as methane (CH4), propane (C3H8), or longer hydrocarbon. In order to be used as a thermal processing atmosphere, hydrogen is liberated from these hydrogen-containing compounds to exist as a pure gas while in use in the hot furnace.

The liberation of elemental hydrogen from its compound carrier can happen at a remote plant operated by an industrial gas company provider, in which case the hydrogen would be compressed or liquified for delivery to the thermal treatment client, or may be conducted at the site of the thermal processor themselves through use of on-site generation equipment. User choices of approaches to pure hydrogen supply will be covered in future columns.

Inside the Furnace

Inside the hot furnace, hydrogen changes metal oxide coatings to pure metals by preferentially reacting with the metal oxides to produce pure metal and water vapor. Thus, the furnace atmosphere dewpoint (a measure of gaseous water content) will increase as the hydrogen simultaneously creates pure metal surfaces and produces water vapor as a byproduct. The water vapor is swept out of the furnace and replaced by the clean furnace atmosphere that flows counter current to the heated metal product. Furnace atmosphere controls for hydrogen-based atmospheres use dewpoint as a key operating parameter.

Hydrogen’s ability to protect the part surface from oxidation is critical in the annealing process. | Image Credit: Abbott Furnace

Since furnaces must open to admit parts for thermal processing, the furnace, the atmosphere system, and the procedures must all be designed to prevent unsafe conditions caused by hydrogen leaking out of the furnace, or air leaking in. Furnaces intended for a flammable gas atmosphere use doors, curtains, and pilot lights (i.e., flame curtains) to prevent hydrogen or other flammable gas from leaving the furnace without being combusted. These precautions avoid explosions inside or outside the furnace.

Furnaces for hydrogen-containing atmospheres utilize unique design and construction approaches to safely use this flammable atmosphere. In the U.S., furnace design and operation is guided by NFPA 86, the furnace code. NFPA 86 defines certain furnace design features and also defines standard operating techniques for safe operation with a combustible atmosphere, such as a hydrogen-containing atmosphere. Similar codes and standards are used in other countries.

Next month, this column will pick up the question of cost by looking at options for generation of hydrogen atmosphere blends. Generation of pure hydrogen will be a future topic.

About The Author:

David (Dave) Wolff
Industrial Gas Professional
Wolff Engineering

Dave Wolff has over 40 years of project engineering, industrial gas generation and application engineering, marketing, and sales experience. Dave holds a degree in engineering science from Dartmouth College. Currently, he consults in the areas of industrial gas and chemical new product development and commercial introduction, as well as market development and selling practices.

For more information: Contact Dave Wolff at Wolff-eng@icloud.com.

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Robotic Material Handling in Heat Treatment

/ CARBURIZING TECHNICAL CONTENT, MANUFACTURING HEAT TREAT TECH, VACUUM FURNACES TECHNICAL CONTENT

Manual loading and batch transfers are giving way to robotic material handling in modern heat treat operations. In this Technical Tuesday installment, Dennis Beauchesne, general manager of ECM USA, examines how automation improves repeatability, boosts productivity, and reduces operator exposure to hazardous conditions near furnace hot zones — and how robotics, vision systems, and mobile transport technologies are helping heat treat facilities build safer and more efficient production environments.

This informative piece was first released in Heat Treat Today’s April 2026 Annual Induction Heating & Melting print edition.

Robotic material handling is rapidly transforming modern heat treat operations traditionally dependent on manual loading and batch transfer. As heat treaters face increased pressure to improve throughput and working conditions while maintaining strict quality standards, automation has become a strategic investment.

Figure 1. SEW-EURODRIVE (Lyman, SC) robotic integration by ECM Robotics features a rear robot and pallets on the left and open area on the right for dunnage storage and management | Image Credit: ECM USA

Heat treat material handling is more than simple part movement. Parts must first be positioned onto fixtures or loaded into bins which are transferred, placed into the furnace, and then moved again for quenching and/or tempering — sometimes under undesirable conditions depending on the installed technology. Additionally, a robot needs to store dunnage in the designated robot area during the processing of the parts in the furnace and then reuse it when the parts are unloaded from the furnace. Dunnage can also be stored in the heat treat area and handled by automation (Figure 1). Robotics and automation promote efficiency and repeatability in this process, which is difficult to achieve with manual operations.

Robotic Advantages

The most significant advantages of robotic material handling are repeatability, consistency, and reduction of work force. Robots execute the same motions cycle after cycle, which ensures uniform loading and proper spacing between parts within fixtures or baskets. For example, in vacuum furnaces, correct part placement is essential to achieving even heat distribution and minimizing distortion. Automated loading eliminates error caused by human fatigue or procedure changes, leading to more consistent and desirable metallurgical results and reduced scrap/re-work.

Improved throughput and increased productivity are other major justifications for robotic integration. Heat treatment can hold-up manufacturing due to cycle times and variable material flow. Robotic systems streamline loading and unloading, reduce wait time between cycles, and allow furnaces to operate at optimal capacity. In high-volume environments, robotics can be managed with upstream machining and downstream finishing processes to create a continuous, automated production line. This level of integration shortens lead times and supports just-in-time manufacturing.

Safety is equally if not more important, as handling baskets or fixtures near hot zones increases operator risk of burns and injuries. Integrating robotics improves workplace safety by removing operators from direct exposure to these hazards. This solution also addresses labor shortages by allowing skilled personnel to focus more on process optimization and quality control rather than repetitive physical tasks.

Specifically in vacuum heat treatment, robotic systems are particularly beneficial. Vacuum furnaces require precise loading to maintain thermal uniformity and protect sensitive components. Automated loaders can transfer loads between heating chambers, quench cells, and temper furnaces in a continuous process flow that minimizes temperature loss and handling delays. Metallurgical results (e.g., hardness, case depth, distortion) are also directly influenced. This is especially helpful for critical and sensitive applications, such as aerospace components and medical devices.

Robotic Components Explained

For manufacturers with in-house heat treat or commercial shops processing multiple part types, the flexibility to program and handle a wide range of part geometries, weights, and batch sizes is vital for efficient operations. Quick-change grippers, adaptive tooling, mobile transport, and vision systems are key robotic components to achieve this goal (Figure 2). Vision systems of today are far more advanced in assisting with the programming phase than those from just a few years ago.

Figure 2. ECM Robotics manipulating parts | Image Credit: ECM USA
Figure 3. AGV (automated guided vehicle), a portable robot that follows a path, delineated physically (e.g. lines on the floor) or through other guide posts (e.g. radio waves, magnets, lasers) | Image Credit: ECM USA

After the load building, automated mobile robots (AMR) or automated guided vehicles (AGV) can also be used to transport loads to and from the furnace. These mobile robots are integrated into factories to automate the transport of loads between different areas without requiring fixed infrastructure (rails or magnetic strips). This system coexists easily with operators and other equipment and adapts well to production floor changes. Integration of AMRs and AGVs frees up operators for more value-added tasks and reduces manual labor time (Figure 3).

Quick-change grippers or end effectors are tailored to the specific application and conditions when in use. Their design focuses on optimizing part clamping, friction, and contact while considering part geometry, cycle constraints, and precision requirements. Gripping technologies are available as pneumatic, electric, magnetic, or vacuum and can handle even the most delicate or fragile components in soft (flimsy) or hard state. Heat treat specific robotics companies, like ECM Robotics, also provide robotic machine vision systems. Integration of these vision systems improves precision and handling to optimize pick & place, palletizing, bulk unloading, and assembly.

For example, by identifying parts based on the diameter or number of teeth on the gear, these systems can then sort and track them within a heat treatment cell through part marking, tray/fixture encoding (QR codes), and weight scenarios or simply virtually through software, which removes the need to use any hardware tracking. Vision systems go beyond the physical movement of parts; by checking for surface imperfections and integrity, they are advantageous for quality assurance purposes.

The most common issue in the heat treating industry when integrating with robots has been fixture warpage. Modern 3D cameras can detect bent or warped pins and alloy trays to allow for movement to a new position. This capability allows for much more robust loading and unloading using moderately warped fixturing, which is common in heat treat operations. While the best consistency typically comes with the use of carbon fiber composite (CFC) trays, it is not necessary to upgrade to all CFC fixtures to get consistent loading and unloading as the system can be designed to handle either alloy trays or CFC as well as some systems with both.

In a recent vacuum furnace installation, a heat treater automated their gear cutting operation to prepare the dunnage before low pressure carburizing. The robotics integration simplified part storage by specific location to allow the robot to “see” with its vision system. Parts were then scanned using QR coding by laser marking and automatically connected to the part’s recipe as stored in the system. Typically, in a modular system using low pressure carburizing, individual cells are utilized and production is recipe driven. In this case, after a part was scanned, the recipe was uploaded into the next available cell, and the scanned parts and heat treat fixture were moved to the cell.

Capital Investment

While the initial capital investment in robotics can be significant, long-term returns are quickly realized through process optimization, better working conditions, reduced re-work, higher up-time, improved quality, and reduced labor hours. Predictive maintenance features and diagnostic monitoring further reduce unscheduled downtime. As manufacturers evaluate total cost of ownership, robotic material handling often proves to be a strategic solution that supports both operational efficiency and competitive positioning.

Future Impact on the Industry

In an industry where precision, repeatability, and reliability are essential, robotic material handling is increasingly valuable for modernizing heat treatment operations. By combining automation with advanced furnace technology or upgrading material handling of older furnace equipment, manufacturers can achieve safer workplace conditions, higher metallurgical quality, and greater overall process efficiency.

Looking ahead, the role of robotics in heat treatment will continue to expand alongside industry trends. Data-driven automation, AI-assisted scheduling, and collaborative robots are opening new possibilities for smarter, more connected facilities. Rather than replacing human expertise, robotics complement it by providing process precision and efficiency to allow heat treat professionals to focus on process innovation and more value-added responsibilities.

References

International Federation of Robotics. 2023. World Robotics Report.

Beauchesne, D. 2025. Heat Treat Robotic Paradigm Shift. Heat Treat Today, January.

About The Author:

Dennis Beauchesne
General Manager
ECM USA

Dennis Beauchesne brings experience of over 200 vacuum carburizing cells installed on high pressure gas quenching and oil quenching installations. He has worked in the thermal transfer equipment supply industry for over 30 years, 24 of which have been with ECM USA where he is the General Manager.

For more information: Contact Dennis Beauchesne at DB@ECM-USA.com.

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