David Burritt president and CEO U.S. Steel Source: U.S. Steel
Access to technology and expertise in integrated mills are among the advantages that will accompany the U. S. Steel–Nippon Steel merger, according to David Burritt, U. S. Steel’s CEO. Heat treatment processes are an element in integrated mill operations within both companies’ profiles.
On December 18, 2023, it was announced that Japanese steelmaker Nippon Steel (NSC) would acquire Pittsburgh–based U. S. Steel. Under the deal, Nippon Steel would acquire the company for $14.1 billion, which totals to $14.9 billion when including the assumption of U.S. Steel’s debt. As part of the deal, Nippon Steel will invest $1.4 billion in U. S. Steel’s assets and will share technical knowledge, stated Burritt during his keynote address to the 2024 Global Steel Dynamics Forum.
“They’re experts in integrated mills, and they want to invest here,” he said.
In April, Nippon Steel released a statement that the merger will include U. S. Steel having access to Nippon’s technologies and R&D advancements, “help[ing] U. S. Steel produce more advanced and environmentally sustainable steel for domestic customers.”
EBNER Group, a global provider of heat treatment solutions, melting, and casting for the aluminum industry has increased its stake in a furnace manufacturer, including annealing furnaces. GNA alutech inc. produces aluminum melting and holding furnaces, homogenizing and annealing furnaces, and cathode sealing equipment.
Robert Ebner CEO, EBNER Group Source: EBNER Group
“We are excited to announce the full acquisition of GNA alutech inc. and would like to thank GNA’s founder, Ted Phenix, for his vision and leadership in building GNA into a successful company over 41 years. Over the last 5 years I was always impressed by the deep understanding and knowledge Ted was able to share with customers. Our strong professional developed to a strong personal friendship,” said Robert Ebner, CEO of EBNER Group.
EBNER Group provides heat treatment solutions for the aluminum industry with the companies EBNER, ETS, EED, Gautschi, TPS, Hazelett, HPI, and GNA, increasing its stake in the latter to 100%. The acquisition marks the culmination of a five-year partnership between EBNER and Ted Phenix, which began with EBNER Group acquiring a majority stake in GNA in 2019.
The leadership of GNA has been placed in the hands of Kaleb Wright, president of business development, and Chantal Coupal, president of operations.
Pictured: Chantal Coupal, president of operations of GNA alutech, and Kaleb Wright, president of business development of GNA alutech
The press release is available in its original form here.
Heat Treat Radio host, Doug Glenn, and guest Bryan Stern from Gasbarre Thermal Processing Systems discuss the shift from single chamber batch furnaces to isolated heat vacuum furnaces. They explore the benefits and challenges of isolated heat systems, including temperature control, cycle times, and cost effectiveness for handling various parts.
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 to Isolated Heat Vacuum Furnaces (00:01:30)
Doug Glenn: We want to talk about something that Gasbarre is calling isolated heat furnaces. In this case, these are vacuum furnaces. What’s an isolated heat vacuum furnace? And why is it called “isolated heat?”
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Bryan Stern: To start off, this isn’t something that’s Gasbarre specific. This is a generic distinction and concept with furnaces. It’s been around for a while, but the primary difference with an isolated heat furnace is that the heat chamber in that furnace stays at temperature, in between processing and throughout the process, and it’s held under vacuum during that time as well.
Doug Glenn: Gotcha. We’re going to talk primarily about vacuum furnaces — though, I know that’s also possible in an atmosphere — and the typical vacuum furnace today is the single-chamber vacuum furnace. Maybe it’s obvious already, but can you explain the differences between the isolated heat and a typical single chamber?
Bryan Stern: The single-chamber, batch processing furnace is by far and away the most prevalent technology that’s used. And the difference is that everything in that process is going to happen in a sequential order — everything from loading, evacuating the chamber, ramping everything (the chamber and the work) up to temperature, holding it, doing whatever process you have, cooling it back down, backfilling it, and then unloading it. It’s all a sequential operation. You close the door, the work sits in the same place, and you run through the entire process.
Gasbarre’s Vacuum Oil Quench Furnace, with isolated graphite heating chamber, includes 2 BAR gas quench capabilities. Source: Gasbarre Thermal Processing Systems
Whereas, with the isolated heat, it remains at temperature. That requires three primary additional components in addition to your single-chamber batch. It requires an extra chamber, for evacuating because you’re going to need an antechamber or a way to load that work in after having pumped it down. So, by default you need a second chamber. You need some kind of dynamic sealing door between the two chambers that you can open once your evacuation chamber is pumped down; and you need some means of moving the work between those two chambers.
These are the fundamental differences. But where it gets interesting is the impact it has on the rest of operations and efficiency.
Doug Glenn: The single chamber has dominated the market for a long time. How have those single-chamber furnaces really affected the design of vacuum furnaces? And are there some significant design differences in these isolated heat furnaces?
Bryan Stern: Yeah. It’s kind of funny, but anyone who’s familiar with single-chamber batch furnaces recognizes there are a lot of challenges to doing vacuum processing that way.A simple way to look at it is if you were trying to cook pizzas in an oven: But if you had to start with the oven cold, open the door, put the pizza in, and then you can’t touch it until the whole thing goes through its process; you heat up the oven and then wait till it cools down at the end and pull it out. It wouldn’t be an ideal approach.
A simple way to look at it is if you were trying to cook pizzas in an oven: But if you had to start with the oven cold, open the door, put the pizza in, and then you can’t touch it until the whole thing goes through its process; you heat up the oven and then wait till it cools down at the end and pull it out. It wouldn’t be an ideal approach.
Bryan Stern, Gasbarre
That’s the distinction with the vacuum portion of it specifically. For a lot of single-chamber batch equipment, you have to pump it down and wait to preheat the oven. That adds a lot of time. So, the then it makes vacuum processing more expensive, and it’s harder to scale. People know there is inconvenience around vacuum processing in general. And the answer to that has typically been to increase workload sizes because if you’re going to have dead time at the front, you’d rather distribute that cost over a thousand parts instead of a hundred parts.
You want to increase the throughput so you’re not waiting for a bunch of little batches and paying for all that dead time with a few parts.
Equipment Challenges with Single Chamber (00:06:32)
Bryan Stern: There’s been a general trend to just increase load sizes, and I am generalizing. It’s not necessary for everything. But you get into some massive single-chamber batch furnaces that are often larger than necessary for the parts. And, unfortunately, those load sizes are kind of detrimental to a lot of the objectives of heat treating.
You have a much more difficult time maintaining uniformity for both process temperature and gas for the parts while you’re heating up and cooling down. And you’re going to have a much higher deviation between the temperature at the center of the load and the surface of the load, as well as process gas concentrations.
That trend toward larger load sizes than necessary (because of the inherent challenges of the single-chamber batch method) leads to other challenges that you then have to overcome. It takes longer to soak out, and quite often (something that I’m sure a lot of people will be familiar with) you end up leaving gaps in the work zone anyway — spaces between parts to allow gas circulation to achieve quench rates enabling you to cool faster because you’re not getting enough gas to the center of the load. Since you have these massive loads, you’ve moved in a direction that’s not really helping anything that you’re trying to do. And that’s a bus that we’ve all been on.
Doug Glenn: So, you’ve got uniformity issues inside the load. And that’s an interesting perspective. The process takes so long inside that one chamber, it tends to increase the size of the load so that you’re doing more at once.
How about the efficiency of the process? If you’ve got a chamber that is designed just for isolated heat, and you’re just heating in that chamber, I would assume that chamber can be designed differently than a chamber in which you’re going to do preheat convective.
Bryan Stern: Absolutely. There are of trying to do everything in one space. I think the equipment challenges come from exactly what you’re talking about — trying to heat and cool in the same space. Anyone who’s been remotely involved in the production of single-chamber batch equipment knows that you’re doing a bunch of things that are in tension with one another. To start, if you’re trying to cool in the same space, very often you’re putting nozzle penetrations all through your insulation pack.
Right away you’ve shot your thermal efficiency in the foot because you have direct radiation out of those nozzles. And people have tried with marginal success to come up with ways of sealing off those nozzles during the heating section and opening them during cooling. Some tried more static approaches, some active changes to the furnace.
But the other issue is that you’re hurting the cooling, too, because you’re restricting your gas flow. You’re heating up the gas that you’re trying to cool with by flowing it through this hot insulation pack. Your parts are sitting inside that heat cage. They’re radiating to a hot surface. Another thing worth pointing out is that often with a single-chamber batch, because you have such a limited time to pump down and you’re trying to decrease your cycle time as much as possible, the installation’s reduced just to help with vacuum levels.
Again, if you’re holding that under vacuum and you can allow it to outgas and decay, now you can have a much thicker insulation pack. You’re not putting penetrations through it. So, it’s helping your thermal efficiency in multiple ways. For example, it’s helping your cooling. When you’re struggling to get those cooling rates, you’re going to do things like bump up gas pressure. Since you’re consuming more processed gas, you’ll put a bigger motor in it — which not only costs more upfront, but it also costs more to run.
That’s a fun fact about especially high horsepower, single-chamber batch equipment: Very often the current rating for the entire system can be driven by the gas blower alone. It’s more than all the rest of the power supply, so they’re not cheap to run.
I’m not saying that you get away with half the size motor, but intuitively you know you’re requiring more than you would need if you placed that load in a dedicated cooling space, no response to gas flow radiating to a water cool jacket. So, it’s a pretty intuitive observation about the way we’re currently approaching this.
Doug Glenn: I don’t think people have thought about it because that has not been the typical way of doing it. It’s almost all single chamber.
Bryan Stern: We’re locked in there.
Doug Glenn: But when you do start thinking about it, it makes a lot of sense that your efficiencies would improve — design and operational efficiencies. All those things would improve because you’ve got dedicated chambers.
Bryan Stern: Another thing with regard to efficiency is your size and your power supply to overcome all those losses, the decreased insulation. When you move to dedicated positions, you know in your position that ramping your power supply can be sized for it. And people have worked to overcome that with typical power supply sizing by doing things like adding multiple taps on the secondary side of the transformer to try to get a better power factor. But if you’re dedicating stations within your equipment, then you can right-size your power supply.
Bryan Stern: “When you move to dedicated positions, you know in your position that ramping your power supply can be sized for it. And people have worked to overcome that with typical power supply sizing by doing things like adding multiple taps on the secondary side of the transformer to try to get a better power factor. But if you’re dedicating stations within your equipment, then you can right-size your power supply.”
Recent Developments (00:13:21)
Doug Glenn: That brings me to a question about the single-chamber vacuum furnaces that have typically been used. To my knowledge, there are not a lot of isolated heat furnaces or dedicated chamber vacuum furnaces out there, although, I know that one of the companies you guys acquired years ago made their name there. But have there been any developments in recent years that have led to more popularity for, or the possibility of doing, isolated heat vacuum furnaces?
Bryan Stern: Yeah, it’s a great question. It’s something that I’ve done a lot of thinking about because we tend to have a mentality with technology that if it was such a great idea, people would be doing it. So, why aren’t more people doing this?
We can learn a lot from looking at another industry. Specifically, the prevalence and immersion of some of the emissions regulations that are coming along is newer to our industry. I think we’ve been able to get away with doing things in a way that might be really inefficient for a while. But it’s not new in some other industries.
There is a great example that I love because it has so many analogies for what we’re looking at in vacuum heat treating specifically: If you look at the history of the adoption of fuel injection in the automobile industry — I’ve always assumed that fuel injection was adopted as soon as it came along because it was a better technology, and it had been around since the 1920s and 30s.
It was developed and used in some military applications, and right away it was hailed as a better technology. It was more efficient, it was cleaner, but people just didn’t want to change. That wasn’t the direction that everyone was moving in. There were some manufacturers that tried. There were some mass-produced vehicles that had fuel injection in the early 1950s, but it still wasn’t taking off.
And then in 1970 the pushed manufacturers specifically to start adapting it more. But it wasn’t welcome. Some supporting technologies needed to be developed better, especially with computers controlling those systems. As reliability increased for those throughout the ‘80s, there were some amendments to the Clean Air Act from 1970. Then it really started to hit the market and be adopted. And what finally sent it is that consumers started to experience the benefits.
Now we don’t even think twice about it. It’s the de facto standard. You’re not going to go find a car dealership in your area that has their specialty line of carbureted vehicles. There are still places they’re used, but the advantages of fuel injection are so great because you’ve got dramatically improved fuel efficiency and much longer engine life. People say cars last way longer than they used to. And it’s because this new technology that had been around for almost a century, by the early 2000s, had been sitting around, and people hadn’t experienced the advantages of it.
One of the things that I love about that analogy is that it also demonstrates this isn’t a complete switch. It’s a gradual change, and there’s still a place for the old technology. It doesn’t mean that isolated are going to completely replace single-chamber batch vacuums. But if you look at the places carbureted engines are still used, you’ll find them on a racetrack or in lawn equipment.
So, in these places where the upfront cost is really important and you’re not getting enough operating time on it, the improved efficiency is not going to pay off if you were to pay up-front since you’re not using it enough. That carries over well to some of the single-chamber batch vacuums because they will always be around, and they’re going to be more preferred for intermittent use applications where the runtime is not as long.
Doug Glenn: That’s an interesting perspective. Have any of the technologies developed recently — like transfer mechanisms, control systems, or anything of that sort? Is there anything substantially new that had to take place before you could get isolated heat furnaces, or have most of those technologies, similar to the fuel injection, been around for a long time?
Bryan Stern: I think they’ve been around like that analogous technology adoption. There’s certainly going to be a refinement of some technologies to be robust for it to work.
Click on the link to read more about Bryan Stern in his Heat Treat Today 40Under40 profile.
There are some good solutions out there. There are some bad solutions out there. And I think the higher possibility of getting into a bad solution with a less mature product is one of those obstacles people are facing. Things don’t change when forces are in equilibrium. So, the fact that we’re not changing as an industry to adopt some of this stuff just means that the forces motivating that change have not overcome the obstacles. There are definitely some obstacles to it.
And I’m sure we’ll get into talking about those some, but we have that nudge from regulation that’s happening. We’ll see, and continue to see, this type of product mature and those dynamic sealing mechanisms and transfer systems. And I think what’s really going to send it is that there are a lot of benefits that address a lot of problems that we’re all familiar with. It’s just not the de facto standard.
There are ways that the industry is organized around the methods that we use currently. A great example of that is the pizza example where you look at the back of the box of pizza, and you’ve got a recipe that says to preheat the oven and then pop it in for 15 minutes. If you can’t do that anymore, and you have to put the pizza in while the oven is cold and let it ramp up, now you have to change the recipe. And that’s the way we’re organized right now. We’re organized with processes for material that’s starting cold. It’s actually a harder way to do things, because the way that different equipment ramps up is harder to control. So, it’s not necessarily a better recipe, but it’s what we have.
The vacuum level specifications are another big impact. In single-chamber batch equipment, you’re exposing it to atmosphere every cycle, and you’ve got to pump it down quickly. So even when you pump it to very low vacuum levels, what’s left is still often oxidizing constituents.
If you can hold it at vacuum (even though it’s not getting to the same ultra-low pressures), and if it’s allowed to absorb from the surfaces and outgassing from materials (even at a higher pressure), you can have a pure environment. And that’s really counterintuitive. It’s not built into equipment specs because people associate the vacuum level with purity, and it’s really more about dew point and the constituents of what’s in the gas. You can have just as pure an environment with much higher pressure. And again, we’re just not organized around that right now.
Continuous and Non-Continuous Systems (00:21:56)
Doug Glenn: Let me restate something you said earlier and tell me if I’m accurate on it. You were saying that because of the single-chamber vacuum furnaces, we tend to increase the load sizes. So, I’m assuming the load size of the isolated heat furnaces could be significantly smaller and, therefore, have better uniformity within the load, both in the heat up and the quench. Is that an inherent advantage of the isolated heat?
Bryan Stern: It’s not specific to all isolated heat equipment. We’d have to get into discussing the fact that you can’t have continuous and non-continuous isolated heat systems. And it’s an important distinction. The distinction being that you have your heat chamber, you’re keeping it at temperature in a multi-chamber batch system, which is still a form of isolated heat equipment. You’re going to be moving your work in and out the same direction.
So, you’ll get a lot of the advantages that we’ve talked about. You’re able to have dedicated design for heating and cooling. You’ll have your thermal efficiency. There are a couple things you’re not going to get. You’re not going to be able to increase the throughput. Whereas, if you move to a continuous furnace where you’re moving that work in, and then you’re moving it to the other side . . . We can keep working with the pizza analogy: If you need more pizzas, and it takes 15 minutes for a pizza, you can move it through three stations for five minutes per station. Now, you’re getting a pizza every five minutes instead of every 15 minutes, right? If you’re able to do that and produce loads faster, then you can decrease the load size. And then you’re going to see all the benefits of decreasing that load size — improved uniformity, faster times, and better cooling.
Click on the image to read “Vacuum Heat Treating in a Carbon-Conscious Market” by Bryan Stern, in Heat Treat Today’s November 2023 Sustainability issue.
But you only get that if you go to continuous. With that specific type of isolated heat equipment, versus just any isolated heat equipment, you’ll get much better thermal efficiencies because in the multi-chamber batch setup you’re not heating and cooling the furnace every time and throwing that energy away. But because you’re loading and unloading on the same size, you’re still going to leave that heat chamber unoccupied, sitting and holding its temperature, consuming energy in between loads. With continuous furnaces, you’re not going to do that. You’re never going to throw all that energy away. There’s minimal holding power required. So, there is a distinction between the continuous and non-continuous isolated.
Doug Glenn: How would it work with a non-continuous isolated heat furnace? If the process required you to preheat, heat, and quench, what is it you’re going to use? Transfer cars? How does that work?
Bryan Stern: If you have multiple heating levels, you can still control the heat. But often you’d introduce it at an intermediate temperature and then ramp it up the rest of the way. So again, all the advantages that you get as far as quenching, typically with a two-chamber piece of equipment like that, your quench chamber is going to serve double duty as your evacuation chamber. You’re putting it into the quench chamber first, evacuating it again, and bringing it back and quenching it.
Challenges with Isolated Heat Systems (00:26:39)
Doug Glenn: These systems sound good, but I’m sure there are some challenges. Are there some drawbacks? I can hear some people saying, these sound like great pieces of equipment — especially the continuous version. I can understand the efficiencies, but what about the complexity? Is the design complexity of these units an issue?
Bryan Stern: It’s definitely one that I face a lot on the application side. It’s a much more complicated process — especially because the process itself is going to impact each of those positions. And you would care if I sold you an oven for your kitchen, and the only thing I cared about was that it can go to this temperature, and it can operate at this pressure, but I didn’t care what you did with it, I didn’t care how much work you get through it. I just had these maximum parameters.
As soon as you move to talking about continuous, you’re right away much more involved in throughput — going to drive and often the number of positions to get the index rate you need for the load size. Now you care how long each step of the process takes, and you’re trying to balance that among positions so that you’re not letting anything sit longer than it needs to because you’re over this particular soak time.
Trying to get continuous equipment sized for an application is more of a process than some people are expecting. And again, we’re just not wired that way. So, you can throw out a spec for a single-chamber batch furnace and say you need this operating temperature, this ultimate vacuum level, and this uniformity . . . and more! But when you come and want to get into a piece of equipment like this, we’re going to have a couple conversations — we’re going to talk about some things no one else is asking. And that’s what can be a hurdle up front, though we’re able to overcome it.
Bryan Stern, Gasbarre, discusses furnace cost effectiveness and flexibility. “It’s just going to be a lot more expensive if you’re doing a process that doesn’t require the way that that furnace was built. So, it’s not that you locked yourself in. It’s just that if you’re constantly changing processes or you have much shorter processes or the throughput isn’t a benefit, then that’s where a single-chamber batch might be a better solution.”
Doug Glenn: But it also may limit flexibility, I assume, of the different processes you could run in that equipment, too. In a batch system, you can put the load in there and do whatever you want, it’s going to potentially take longer to get it done. But maybe in an isolated heat system, where the heat chamer is only designed to do X, maybe you can’t do X times two. Does that make sense?
Bryan Stern: Yeah. It’s not as much true for a two-chamber or multi-chamber isolated heat batch style furnace because you have the same flexibility of dedicated design. On a continuous furnace, but if you’re going to be doing that a lot, is it worth paying for something that can be optimized one way if you’re going to be using it in a flexible way. They have a lot of flexibility — I would argue just as much as batch. It’s just going to be a lot more expensive if you’re doing a process that doesn’t require the way that that furnace was built. So, it’s not that you locked yourself in. It’s just that if you’re constantly changing processes or you have much shorter processes or the throughput isn’t a benefit, then that’s where a single-chamber batch might be a better solution.
Cost Effectiveness (00:30:23)
Doug Glenn: And then the other objection that jumps to my mind is capital equipment outlay. Can we address that, compared to single chamber?
Bryan Stern: This is this is another one that’s near and dear to my heart because I think there’s a lot of misconception here since it’s very application specific and hard to answer generally. But like we talked about, you’re going to have another chamber.
So, if you’re looking at a smaller system, it may not immediately be more cost effective. If you’re looking at a continuous system that’s replacing several furnaces, now you’re not paying for that oversized power supply on each piece of equipment; you’re not paying for a pumping system for each piece of equipment; you’re just buying it for the one evacuation chamber. Or maybe you have a backup, but now you’re starting to distribute and be much more selective about your material cost, and there’s definitely a break-even point in there.
It’s really a question of whether or not the process improvements are enough of a benefit on the smaller size. But very quickly the upfront cost starts to lean in favor of the continuous, especially if you’re looking at multiple pieces of equipment.
But the bigger thing here, the thing that I feel more passionate about, is that we tend to get really hung up on the upfront cost. And I think that’s something that can be very detrimental to missing out on value. It’s very easy to say: I’m going to have this amount of revenue, I’m going to pay this for equipment, and I’m not going to dive into maintenance and operating costs — and that’s a difficult question to answer but is a huge piece of the puzzle. Yet we often don’t put in the legwork because the information is not readily available. And it takes a more sophisticated accounting approach to look at project value over the life of the equipment.
Intuitively, we know that you could pay more for something that would improve efficiency or throughput or performance because in the long run that would pay off. And going back to the car analogy, when is the last time you bought a car and didn’t pay any attention to the fuel economy on it? It’s hard to do that without a little bit more accounting elegance.
Intuitively, we know that you could pay more for something that would improve efficiency or throughput or performance because in the long run that would pay off. And going back to the car analogy, when is the last time you bought a car and didn’t pay any attention to the fuel economy on it? It’s hard to do that without a little bit more accounting elegance.
Bryan Stern, Gasbarre
So, you have to look at the cash flow problem, do something like a net present value approach. And when you start looking at the operating cost savings, the efficiency improvements, and then a huge one that people miss is in the single-chamber batch furnaces we’re heating it up and down. That’s aggressive thermal shock and cycling. A lot of design goes into trying to get components to last because there’s thermal ratcheting and things wear out super quickly. For these continuous systems that are just sitting at temperature, that goes away for the most part.
They’re still consumable products, but the maintenance costs are dramatically improved, and you can talk to people who are using the systems. But again, that’s not something a lot of people have experienced, and it’s hard to quantify. So, if you just look at the upfront costs then it’s easy to miss out. You’re looking for an aggressive payback because you’re just hoping it’s going to cover the operating and maintenance expenses versus actually factoring those in and saying that those overall for the project life are going to increase value.
Limitations and Benefits of Isolated Heat (00:34:09)
Doug Glenn: That makes sense. Two final questions for you here: Are there any types of companies out there where it doesn’t make sense to use an isolated heat type system, whether it be a double chamber or continuous or whatever? And are you seeing, from the activity of , any industries that really should be looking at them?
Bryan Stern: Answering your first question with regards to the limitations, there are a couple situations where you’re not going to want to be looking at isolated heat.
One of those is really large parts. If an individual part is going to take up your whole work zone, then you’re not going to be able to decrease the load size and go to continuous and match the throughput. So, very large batch applications are going to be an obstacle; large parts are one area that it’s not going to shine. We’re seeing the 36” x 36” x 48” work zone is the practical cutoff. Another is the ability to use work TCs to monitor internal temperatures of the parts. That’s possible with continuous equipment. You can do a data pack and record temperatures, but it’s certainly not as convenient. So, when it comes to R&D, validating internal temperatures, and processes that require that, that’s another hurdle and limitation of this type of system.
The footprint is another one due to a second chamber for a batch style process is probably going to be larger in the space that it occupies because you’re not getting smaller in the work zone. So, it’s a question of whether you have the floor space, and do the other benefits of that system make up for the space it’s going to take up?
Doug Glenn: Those are good caveats. How about industries that you’re seeing who really should be adopting these things that either are or ought to be?
Bryan Stern: I don’t think it’s super industry specific, but there are some processes that benefit. And just a couple would be anything with a really short cycle time, because the dead time is going to consume more of the process.
If you can eliminate that and you only need to be at temperature for a little piece of time, then getting the rest of that dead time to be in parallel with the process to increase your throughput makes you a great candidate. But on the other hand, long processes are also a good candidate. If you’re holding it at temperature for a long period of time, boosting that efficiency while you’re in temperature, and better matching a power supply to what you’re doing.
So, good candidates could have short or long cycle times, involve any processes that require tight control, or benefit from isolating them from the space. Censoring can be a good candidate for rising carbon trading, where you can now actually have a dedicated space that maybe even operates at a higher vacuum level for whatever you’re trying to do, or you’re not worried about contaminating the parts with whatever process we’re running, or you need a tight time control. So, gas processes like that.
Oil quenching is an obvious candidate because you already have two chambers most of the time and isolating it, maintaining it at temperature, and keeping it clean from any oil vapors makes it a great example.
For anything with expensive parts, you can minimize the risk by decreasing the load size instead of having a many thousand-pound load where if something goes wrong, you’ve lost it. And especially for applications where that can be a really expensive thing if something goes wrong, you’d rather have it go wrong with much less material at risk.
Doug Glenn: I would think traceability is also probably easier in one sense. With this isolated heat system; you don’t have a huge batch in there. You’re processing potentially smaller batches, and you’re able to isolate which batches are at what temperature or what kind of quench they go through. Those may be some advantages.
Bryan Stern: You had a very specific application for a client who was concerned with a lot of small parts and traceability down to each part, and we’re looking at that system. Anytime you have a high volume of work, if you’re looking at multiple batch, single-chamber batch furnaces to meet throughput, that’s one of the biggest indicators you really should probably be looking, or at least considering, these other systems. And any time you have a lot of small parts in baskets, a large single-chamber batch furnace with stacked baskets of tiny parts, you’ll probably have a lot of benefit.
Doug Glenn: I assume that if somebody is looking at purchasing multiple single-chamber furnaces, you guys would have some sort of a calculator to help them assess if it makes sense financially and process-wise to go with six batch furnaces or one continuous. Is that a safe assumption?
Bryan Stern: Yeah, that’s one of my favorite parts of the process is to take a specific application, go through and break it down, and put together that full project ROI where you’re actually starting to assemble what are we looking at for maintenance costs? What is it going to cost to operate? And now you’re starting to see at a project level, not just the upfront cost, which option is going to be best. And it is so application specific. It’s kind of neat to walk through that with a client and see what comes out the other end. Because at the end of the day, you want what the best solution is. It could be this or that. But when you can actually put that picture together for a process and assist someone with picking the best equipment for what they need for their process, that’s fun.
Doug Glenn: And just for the listener’s benefit, because we haven’t done a lot of talking about your company Gasbarre Thermal Processing Systems. You guys can provide either the isolated heat systems or, if you do the calculations on your handy dandy spreadsheet and it turns out they’re better doing the standard single chamber, you guys can do those, too. So, it’s not like you’re going to push one over the other but whatever makes sense. Right?
Bryan Stern: I see that as a huge advantage. You’re not going to get a bias of us at Gasbarre trying to push you into this because it is what we’re selling. We are able to wade through that decision with the client and help pick the equipment that’s best for them.
Doug Glenn: Helping them make a better choice, super, Bryan. Thank you.
About the Expert
Bryan Stern is the product development manager at Gasbarre Thermal Processing Systems. He has been involved in the development of vacuum furnace systems for the past 8 years and is passionate about technical education and bringing value to the end-user. Bryan holds a B.S. in Mechanical Engineering from Georgia Institute of Technology and a B.A. in Natural Science from Covenant College. In addition to being a member of ASM, ASME, and a former committee member for NFPA, Bryan is a graduate of the MTI YES program and recognized in Heat Treat Today’s40 Under 40 Class of 2020.
As heat treaters strive for a sustainable future, pressure mounts to make the right choices while running commercially viable operations. In this Technical Tuesday installment of a continuing series, guest columnist Michael Mouilleseaux, general manager at Erie Steel, Ltd., explores the potential ramifications of the DOE effort for industrial decarbonization in the heat treating industry. The first installment, “US DOE Strategy Affects Heat Treaters”, appeared on April 10, 2024, in Heat Treat Today, as well as in Heat Treat Today’s March 2024 Aerospace print edition.
This informative piece was first released inHeat Treat Today’s May 2024 Sustainability Heat Treat print edition.
As regulatory agencies set industrial decarbonization goals aimed at achieving net zero greenhouse gas emissions (GHGE) by 2050, heat treaters should prepare for action. But where do heat treatment technologies stand today, and what is the path going forward?
Background
President Biden’s 2021 executive order calling for a “clean energy economy” led the U.S. Department of Energy (DOE) and the Environmental Protection Agency (EPA) to develop “The Industrial Decarbonization Roadmap,” a strategic plan for reducing industrial emissions. The plan identified five sectors — chemical, petroleum, iron and steel, cement, and food and beverage production — as targets for mitigation efforts. According to “The Roadmap,” process heating operations within these five industries represent the greatest opportunity to apply what were established as four pillar technologies:
Energy efficiency
Low carbon fuels, feedstocks, and energy sources (LCFFES)
Carbon capture, utilization, and storage (CCUS)
Industrial electrification using green electricity
In May 2023, heat treating was specifically named as a target process for reducing GHGE during the DOE’s Office of Energy Efficiency & Renewable Energy’s Low Carbon Process Heating Forum.
A Closer Look at the Technology Pillars
To determine the path forward, it’s important to understand where heat treatment technology stands today regarding the four pillars.
Energy Efficiency: Among energy efficiency opportunities are furnace insulation, controls, and burner design. According to furnace and controls manufacturers that I have spoken with, advancements in insulation and heating system controls offer less than a 20% opportunity in efficiency improvement over
LCFFES: In the U.S., the primary hydrocarbon fuel for heat treating is natural gas, which has an average (commodity) cost of $2.57/MMBTU. Hydrogen has been endorsed as the preferred replacement. Hydrogen manufacturing and distribution issues aside, hydrogen has a 2023 (commodity) cost ranging from $14.00 to $40.00 per MMBTU, and a carbon footprint of 30–130% that of natural gas. “Green hydrogen” is “under development.”
CCUS: Carbon capture, utilization, and storage is currently relegated to natural gas production operations where the captured CO2 is injected into existing wells to “enhance” production. Although the DOE suggests development of advanced CO2 capture technologies are still underway, a 2023 Congressional Budget Office report states there are “fifteen CCS facilities . . . operating in the United States . . . [with] an additional 121 . . . in development.” It is fair to state there are no CCS (carbon capture and storage) facilities currently operating on the scale of a heat treating operation.
Electrification: For electrification to be impactful, electricity must be generated via green sources. Currently, 40% of the electricity generated in the U.S. comes from natural gas, 20% from coal, 19% from nuclear, 10% from wind, and 3% from solar. It is my opinion that, regardless of the incentives federal and state governments offer wind and solar energy operations, they will not reach the scale — and most certainly not the reliability — necessary to achieve the stated 2035 GHGE goals.
Cost also must be considered. The average U.S. cost for electricity was $0.086/KWH in 2023. In California, however, the cost for electricity generated with 40% renewables was $0.1819/KWH. In Germany, it was $0.289/KWH with 55% renewables. To put this into perspective, today the differential in (industrial) electricity (commodity) costs demonstrably increase as the percentage of that electricity is generated by “green” sources. To think that this trend is going to be reversed by federal mandate is paradoxical.
A Realistic Look at the “Road Map”
While industrial decarbonization targets called for an 85% reduction in GHGE by 2023 and net zero by 2050, the goals seem unreachable using currently available technology. Replacing natural gas with hydrogen will result in significant cost increases as the commodity is 5–15 times more expensive, the equipment will require retrofitting to accommodate hydrogen, and the national infrastructure will need to be modified for hydrogen.
Electrification of existing gas-fired processes will result in a cost increase of four times, according to DOE estimates; however, based on today’s cost trends, 7–9 times higher is more likely. Additionally, the cost of converting equipment to electric operation must be considered. Mitigation efforts suggested by the DOE include improvements in efficiency that rely on yet-to-be-developed technologies and cost reductions in electricity facilitated by the wholesale use of renewable energy.
Overall, decarbonization efforts are noble. The timeframe and methodology, however, are unrealistic as they are based on the use of still-conceptual technologies.
What Can Heat Treaters Do?
Following the lead of the automotive industry may be key. This sector reacted to the government mandates for GHGE reductions by going all in for electrification — with projections of 50% electric vehicles by 2030. A funny thing happened; these vehicles were not wholly accepted by the American public. The auto industry, led by the dealers, with the support of the UAW, and the car manufacturers petitioned their U.S. Representatives to “pause” these requirements. This political pressure caused the EPA to roll-back the implementation schedule.
Heat treaters must act now with a similar effort, but it must be aimed at preventing the promulgation of regulations that rely on still-conceptual technologies within an unachievable timeframe. Contact your local government leaders; let them know what we do means jobs and tax revenues. Contact your U.S. Representatives and Senators to let them know heat treaters are critical to our national security, the transportation system, and, in fact, the infrastructure of this country. What we do should not be outsourced, and we need to be given all the considerations of a critical industry.
The next column in this series will address the role of process heating in GHGE, analyze DOE assessments of GHGE for industry and process heating operations, and propose a fact sheet intended for use in our effort to set a realistic timeline for decarbonization goals In the next column, we’ll address potential ramifications of the DOE effort for industrial decarbonization in the heat treating industry to help you be better informed and prepared.
About the Author:
Michael Mouilleseaux General Manager at Erie Steel, Ltd.
Michael Mouilleseaux is general manager at Erie Steel, Ltd. He has been at Erie Steel in Toledo, OH since 2006 with previous metallurgical experience at New Process Gear in Syracuse, NY, and as the director of Technology in Marketing at FPM Heat Treating LLC in Elk Grove, IL. Michael attended the stakeholder meetings at the May 2023 symposium hosted by the U.S. DOE’s Office of Energy Efficiency & Renewable Energy.
For more information: Contact Michael at mmouilleseaux@erie.com.
Attend the SUMMIT to find out more about the DOE’s actions for the heat treat industry.
Find Heat Treating Products and Services When You Search on Heat Treat Buyers Guide.com
Today’s News from Abroad installment brings us news of a climate-neutral metallurgical thermal process center in Germany, a twin-ladle furnace station in Brazil, and a Korean steel maker gaining furnace efficiency.
Heat TreatTodaypartners with two international publications to deliver the latest news, tech tips, and cutting-edge articles that will serve our audience — manufacturers with in-house heat treat. heat processing, a Vulkan-Verlag GmbH publication, serves mostly the European and Asian heat treat markets, and Furnaces International, a Quartz Business Media publication, primarily serves the English-speaking globe.
ArcelorMittal Brasil Orders Twin-Ladle Furnace Station from Danieli
ArcelorMittal’s Tubarão integrated steel plant in Serra, Espirito Santo state, where Danieli will install twin-ladle furnace station. Source: furnaces-international.com
“ArcelorMittal Brasil has chosen Danieli Centro Met technology and equipment for a twin-ladle furnace station to be installed at the Tubarão integrated steel plant in Serra, Espirito Santo state, where 7+ Mt/yr of high-quality, flat carbon steel products are produced. The new twin-ladle furnace station will be placed in the melt-shop bay between converters and continuous casting machines to complete the refining area, remove sulphur contents and make quality adjustments to the steel bath, to produce USIBOR steel for automotive applications.”
TU Bergakademie Freiberg Opens Climate-Neutral Metallurgical Thermal Processing Center
At TU Bergakademie Freiberg, the simulation of a torch in a test furnace is part of developing technologies that could replace the natural gas burners of the future. Source: TU Bergakademie Freiberg
“’Our goal is emission-free thermal processes, which we optimize through a closed loop system,’ says Professor Gotthard Wolf, head of the Foundry Institute at TU Bergakademie Freiberg. In order to get closer to this goal, two technologies have already been developed at the TU Bergakademie Freiberg that could replace the natural gas burners of the future. When using green electricity, the process step of melting, for example of aluminum, becomes completely CO2-free. These are a plasma-heated hot gas flare and an inductively heated got gas flare. ‘Each of the electrically operated flares could be replaced in existing melting furnaces without the mostly medium-sized foundry companies having to invest in alternative furnaces,’ explains Professor Wolf.”
Tenova’s NextGen® System Enhances Dongkuk Steel Mill Furnace Efficiency
The installation and commissioning of Tenova’s NextGen® will provide enhanced EAF efficiency, real-time monitoring, and control capabilities. Source: furnaces-international.com
“Dongkuk Steel Mill Co. Ltd., a leading steelmaker in Korea, has recently contracted Tenova Goodfellow, Inc, a subsidiary of Tenova, a leading developer and provider of sustainable solutions for the green transition of the metals industry, to improve its furnace efficiency. The scope of the contract involves the supply and installation of Tenova’s NextGen® System at Dongkuk’s Incheon Plant in Dong-gu, Incheon, Republic of Korea. The Next-Gen® System, tailored for Dongkuk Steel’s 120-ton AC shaft furnace, incorporates advanced hardware and temperature sensors for off-gas measurement which include two sampling stations and a central cabinet.”
Thirteen new manufacturing jobs will open up with the $23.5 million expansion of an Alabama heat containment refractory production facility. The Ohio-based company supplies products used in a variety of industrial applications, including heat treating operations.
Paul Jamieson President & CEO Allied Mineral Products
Allied Mineral Products, an Ohio-based producer of monolithic refractory ceramics, recently broke ground on the major expansion at its Pell City, Alabama, location. The growth project will add a 200,000-square-foot production facility on the company’s current site and expand the workforce with thirteen new manufacturing jobs added to the company’s current workforce of 81 full-time employees. The project is expected to be completed in late 2025, increasing the facility’s production capacity and improve efficiency. State and local officials joined executives and employees of Allied Mineral Products, LLC (Allied) at the groundbreaking ceremonies marking the investment.
“Our partnership with Alabama is strengthened yet again with the expansion of this plant which we originally built in 2019,” said Paul Jamieson, president and CEO of Allied Mineral Products. “Locating our facility in Alabama was part of a long-term strategy to expand our manufacturing presence in the south to be closer to our customers. Because of the quality of this workforce and the local support here, our growth in Alabama has been faster than we planned. We are excited to be expanding our facility so soon and are confident this will help us to continue that growth.”
The press release is available in its original form here.
Roller hearth furnaces are known as the work horses of the heat treating industry. Though they may be common, these furnaces still hold some surprises — namely, their diverse applications, potential to be fully automated, and long life span. Five industry leaders provide insight into the current furnace features and how to optimize them for annealing heat treat. As you read, notice the different emphases each expert addresses.
This Technical Tuesday was originally published inHeat Treat Today’sJanuary/February 2024 Air and AtmosphereHeat Treatprint edition.
Application Determines Customizable Furnace Features
This type of furnace is highly customizable, and, as Tim Donofrio, VP of Sales at Can-Eng Furnaces International explains, knowing the application will determine furnace features.
What Features Do You Offer on Your Roller Hearth Furnace for Annealing Various Materials?
Tim Donofrio Vice President of Sales Can-Eng Furnaces International, Ltd. Source: Can-Eng Furnaces International, Ltd.
The following is based on roller hearth furnaces operating at or above 1400°F.
Annealing furnace features depend upon the material being processed and the metallurgical process being carried out. They can be provided with a wide variety of features for preheating, annealing, slow cooling, oxidizing or bluing and accelerated cooling.
Preheating features include direct or indirect heating applications, under air or controlled atmospheres. Preheating in some cases requires features for burn-off of residual blanking fluids prior to entry into the critical anneal chamber and as such, the off -gas must be appropriately addressed.
Annealing can be a direct or indirect heating application using natural gas, blended hydrogen/natural gas, and electrical energy sources. Process protective atmospheres include N2, Exothermic gas, Endothermic gas, N2 + H2, and H2. In some cases, process atmospheres must be carefully controlled and monitored to very low O2 PPM levels to ensure correct oxides are formed or, alternatively, a bright oxide-free finish is achieved, something very critical when annealing electrical steels for transformer core and motor annealing. Today we see a rise in the use of roller hearth furnaces for the manufacture of transformer core and motor cores, processing electrical steels and amorphous metals. This is largely a result of the electrification of the world.
Post-annealing cooling and bluing are paramount to the process success. In most cases, cooling and soaking stages are provided through the integration of direct and indirect cooling methods that include air, water, and externally chilled atmospheres that can be directly injected into the furnace system and recirculated.
How Is Your Roller Hearth System Unique?
Roller hearth furnaces are the work horse of the industry; they are used for a variety of other heat treating applications. For example, roller hearth furnaces can also be used for low temperature curing, tempering, and aluminum heat treating applications. These lower-temperature roller hearth furnaces do not operate above 1400°F and are built with different fabrication and refractory standards. Of course, additional high temperature applications include neutral hardening, case hardening, carbonitriding, isothermal, and spheroidizing annealing and normalizing.
Roller hearth furnace
Can-Eng Furnaces International offers roller hearth annealing furnaces that meet the stringent demands of today’s manufacturers where safety, product quality, and equipment reliability are at the top of our engineers’ minds during design and development. Can-Eng has developed a strong user base that has benefited from design features that ensure tight temperature control and repeatable thermal profiles while also tightly controlling process atmospheres. This is achieved by integrating some of the best available heating and atmosphere technologies while being combined with state-of-the art automation and robotics to deliver the lowest cost of ownership processing systems to our clients.
What Are Best Practices for Training In-House Operators on Roller Hearth Annealing?
Our company promotes hands-on and classroom multi-level training of operators, maintenance staff, and engineers. This provides a complete and full understanding of the equipment and the opportunity to train within the company for future talent development.
What Are the Furnace’s Operational Advantages?
Can-Eng integrates operator-friendly features that contribute to the reduction in energy and atmosphere consumption while minimizing the carbon footprint and emission levels. Combined with on-board system diagnostics, monitoring, and data collection, these allow for minimal operator involvement.
What Is the Most Common Heating Method?
Today, the most common methods are both natural gas and electric. However, Can- Eng works to integrate features that provide our partners with the benefits of reusing waste heat sources such as flue gases within the system or facility to improve operating efficiencies.
What Are the Challenges in Operating This Type of Furnace?
These (atmosphere control, maintenance, uptime, and temperature control) are all typical challenges that are addressed in design. The key is to design flexibility, ease of use, and operator-friendly features to avoid problems in the future when the client wants to process different products in a different way.
Training and Maintenance To Optimize Uptime
Bob Brock, sales engineer at AFC-Holcroft, emphasizes the importance of training and maintenance to best operate the roller hearth system.
What Features Do You Offer on Your Roller Hearth Furnace for Annealing Various Materials?
Bob Brock, Sales Engineer, AFC-Holcroft
Roller hearth furnaces are designed to provide greater uptime, ease of maintenance, and trouble-free operation and are always custom-designed to meet our clients’ specific processing requirements.
Modular designs are available to accomplish basic heating, holding, and cooling segments but also to incorporate burn off, cyclic spheroidizing, bluing, fast cooling, and blast cooling under controlled atmospheres ranging from Endothermic to Exothermic gases, nitrogen, hydrogen, and products of combustion. A broad range of material handling automation and control platforms providing total data monitoring, controlling, tracking, and acquisition capability are also offered.
How Is Your Roller Hearth System Unique?
AFC-Holcroft has designed, built, and commissioned hundreds of roller hearth manufacturing, and fi eld support teams have extensive knowledge and experience with annealing, isothermal annealing, normalizing, carburizing, and solution and aging processes for ferrous and nonferrous applications. This expertise has well positioned us in the roller hearth furnace market.
What Are Best Practices for Training In-House Operators on Roller Hearth Annealing?
3D image of annealing roller hearth furnace Source: AFC-Holcroft
We use a two-step approach when training operators on our equipment. First, hands-on training provides the best opportunity to learn equipment operation, startup and shutdown procedures, as well as maintenance tasks. Second, we follow up hands-on training with classroom discussions to further the operator’s knowledge of equipment and the use of our operating manual. Our two-step approach arms our client operational team with the confidence and knowledge they need to be successful from day one.
What Are the Furnace’s Operational Advantages?
Roller hearth furnaces are designed and built with longevity and uptime in mind. From our integrated preventative maintenance reminders, robust construction, and user-friendly controls, it’s not uncommon to see our equipment still in operation for 50 years or longer.
What Is the Most Common Heating Method?
Natural gas continues to be the predominate heating source in North America, although we have seen an increased interest for alternate heating sources like electric, hydrogen, and bio over the last several years. We anticipate this trend to continue as companies invest in minimizing their carbon footprint, and can provide clients with carbon footprint analysis and operational costs on our equipment.
What Are the Challenges in Operating This Type of Furnace?
Routine equipment maintenance is key to operational uptime. AFC-Holcroft offers a wide range of preventative maintenance programs for our clients. The services can be customized to include hot and cold inspections, thermal imaging, burner tuning, and equipment optimization analysis.
Consistency Is Key To Increase Furnace Life
Given that the roller hearth furnace is a continuous system, understanding how the system works and operating at the correct, consistent rate is crucial for success. Jacob Laird, mechanical engineer at Premier Furnace Specialists, dives in deeper.
What Features Do You Offer on Your Roller Hearth Furnace for Annealing Various Materials?
Premier Furnace Specialists (PFS) is capable of building annealing furnaces for a wide range of workloads. We have built small batch normalizing furnaces with simple manual roller hearths, as well as 120+ foot long fully automated annealing roller hearths with multi-zone control and automatic load staging. We also offer a variety of controlled heating/cooling systems and atmosphere generators and gas dryers to provide optimal annealed part quality. Controlled cooling systems may include: radiant tube indirect cooling, atmosphere forced convective cooling, and post-process forced convective cooling with ambient air.
How Is Your Roller Hearth System Unique?
Jacob Laird Mechanical Engineer Premier Furnace Specialists, Inc./BeaverMatic Source: Premier Furnace Specialists, Inc./BeaverMatic
One of the unique uses for annealing furnaces is for soft magnetic steel alloys aft er they have been cold worked or formed. This is often used for products inside electrical equipment such as electric motors or transformers where grain growth and residual stresses may affect the magnetic properties of the material. The most cost-effective process for this heat treatment is through a continuous atmosphere with a reducing atmosphere (often provided by a lean Exothermic gas atmosphere). For this process, the atmosphere requires a specific range of hydrogen alongside a controlled heating and cooling recipe with multiple stages.
Premier Furnace Specialists also provides the accessory equipment that can be required for a complete annealing operation. We will build the Exothermic gas generators (rich and lean), Exothermic gas dryers (air and water cooled), nitrogen/methanol/hydrogen (or other bulk atmosphere) gas trains/delivery systems, water recirculation and convective cooling systems, load management equipment/software, and any other required pre/post processing equipment right here at our facility in Farmington Hills, MI. By building all of the ancillary equipment alongside the annealing furnace, it allows the client to benefit from installation of the entire system at once, identical spare parts across all pieces for easier maintenance, identical control systems with consistent terminology for ease of operator training, a single contact source for all engineering assistance and troubleshooting, as well as a service department capable of quickly responding to requests for both our equipment and any other equipment the customer may already have.
A 16 ½ ft. wide x 9 ft. high x 125 ft. long roller hearth furnace with four
heating zones and two cooling zones. Maximum temperature of 1500°F,
nitrogen gas atmosphere.
Concerning efficiency, combustion heating systems can be customized with preheat and recuperation systems, recuperative or regenerative burners, or multi-legged radiant tubes to minimize gas train complexity and NOx emissions while maximizing efficiency and profitability. Electrically heated systems can be equipped with SCR power controls which minimize temperature swings at setpoint, provide optimum work chamber uniformity by eliminating heat surges, and conserve energy by reducing current draw at operating temperature. Processes can also be equipped with digital atmosphere analyzers, flowmeters, and gauges capable of displaying the remote equipment conditions at localized control stations or on mobile devices.
What Are Best Practices for Training In-House Operators on Roller Hearth Annealing?
Specifically for roller hearth furnaces, operators and maintenance personnel must understand the rollers and drive systems to ensure products continue processing at a correct rate. For continuous systems in particular, drive failures may result in the loss of large volumes of product that often cannot be recycled as well as lengthy purge/shutdown/ startup times.
As an example, chain and sprocket driven rollers just only be locked down on the drive side of the furnace so that thermal expansion allows them to grow on the idle side. Otherwise, the sprockets may walk out of alignment and cause a multitude of long and short-term issues such as rollers seizing and warping, drive faults, load crashes, and timing issues between multiple driven segments.
Th e best practice would be for operators to be trained to understand how major components of the furnace may affect the part quality. This knowledge will also assist in troubleshooting issues that may arise and correcting them before they become worse.
What Are the Furnace’s Operational Advantages?
Roller hearth furnaces can handle a large assortment of part sizes by varying the roller diameters and spacing between them. For small parts, the rollers can be used to drive a mesh/cast belt or convey trays. For long parts, they can rest on the rollers with multiple support points. The bar, pipe, and tubing industries use incredibly long roller hearth furnaces while many industries process heavy wire coils in them. By segmenting the roller drives and utilizing VFDs or servomotors, roller hearth furnaces become capable of staging loads, customizing processing times, and oscillating at temperature to prevent rollers from warping under heavy loads.
What Is the Most Common Heating Method?
Premier has seen a steady demand for gas fired roller hearth equipment, but most quotes nowadays also request pricing for an electric alternative to compare against. The end user’s facility location and local utility regulations are typically the deciding factor.
What Are the Challenges in Operating This Type of Furnace?
A common challenge for any continuous furnace is maintaining consistent production and limiting shutdowns or idle periods. Large continuous furnaces burn up a significant amount of energy even when idling, so any time spent not in production becomes costly. Even when the equipment sits powered down, start-up procedures including insulation dry-outs, inert gas purge requirements, and atmosphere seasoning can take days until production can resume.
However, once consistent production is maintained, part quality, part consistency, and energy efficiency can be noticeably better than batch equivalents.
Issues can be avoided by noting areas of concern as they arise and following routine maintenance procedures until scheduled annual or biannual shutdowns (often around holiday breaks). Then additional time can be given to address potentially major issues with service visits and inspections by OEM service teams.
An Eye on Energy
Reiterating the customizable nature of this style furnace, Ryan Sybo, project manager at SECO/WARWICK USA, comments on the attention on energy usage that clients and suppliers share.
What Features Do You Offer on Your Roller Hearth Furnace for Annealing Various Materials?
Ryan Sybo, Project Manager,
SECO/WARWICK USA
We offer a wide variety of options as a custom furnace company. We can tailor the furnace to meet the unique needs of individual clients. On annealing furnaces specifically, we offer a controlled cool chamber and a steam blue chamber.
Individual roll sections can be started, stopped, reversed, oscillated, and run at the same speed or at different speeds for maximum process versatility.
Atmosphere integrity is assured through welded gas-tight shells, sealing doors, and pressure control systems.
Fast and slow heating and cooling rates are possible. Plus, pre-heating can be employed.
Post-heat treating processes like steam blue are possible.
Furnace doors are specially constructed and insulated for operation within the temperature zones in which they are located, minimizing stress and warpage caused by temperature differences.
Heating and cooling sections incorporate dependable, high-quality components for long-life operation.
High-speed transfer between sections allows closely spaced workloads or work trays with separation during transfer through doors, assures optimum use of hearth space, and minimizes atmosphere mixing. All door openings can be adjusted to workload heights, permitting faster operation and minimizing atmosphere mixing.
How Is Your Roller Hearth System Unique?
The controlled cool chamber offers precise control of the cooling rate. The steam blue chamber is used to develop a blue oxide, Fe3O4, for electrical insulation characteristics.
Our company has been designing and manufacturing furnaces for over 123 years, and we have been exploring new refractory materials and more energy-efficient burners and recuperators, as well as offering state-of-the-art atmosphere controls.
What Are Best Practices for Training In-House Operators on Roller Hearth Annealing?
Our furnaces are all built to the latest NFPA 86 and OSHA standards, however, safety training like HMI is also important.
What Are the Furnace’s Operational Advantages?
Several of this furnace’s operational advantages include:
Continuous Unlimited Work Flow: Provides better efficiency than batch processing since the workload can continuously feed into the furnace.
Quick, Easy Installation: For SECO/WARWICK USA, these are normally built at our manufacturing facility and tested, then disassembled into sections to fit on a truck or shipping container.
Long Life: A 40-year lifespan is typical. Less stress on furnace components from faster or constant temperature recycling when compared to belt, chain, or pusher units.
Smaller Factory Footprint: Manufacturers can save about half of the floor space than with multiple batch units.
Flexible Operation: Roller drives can be slowed, sped up, or stopped. Process parameters can be changed, any atmospheres can be used from H2 to air, plus door separations can be used between sections for better separate processing functions.
Lower Production Costs: Each furnace is custom-designed for continuous operation at the desired operating temperatures. Less waste from heat-up and cool-down cycles used in batch systems and in-line processing makes energy recuperation easier to integrate.
What Is the Most Common Heating Method?
Gas fired is the most common, however, we have been seeing a lot of inquiries for electrically heated roller hearth furnaces.
Geographic location is also a big determining factor because some areas have more access to natural gas that can offer reduced operating costs.
What Are the Challenges in Operating This Type of Furnace?
There are no challenges in operating this type of furnace due to our custom-engineered, user-friendly automatic furnace controls. Preventative maintenance can be included in our control systems to remind operators and maintenance personnel to service the equipment. Furnace data and alarms are logged and ready for download and review.
Leveraging Efficient Designs To Process Heavy Workloads
Kelley Shreve, general manager at Lindberg/MPH, hones in on the significance of roller hearth furnace workload capacity as a lynchpin to heat treat operations.
What Features Do You Offer on Your Roller Hearth Furnace for Annealing Various Materials?
Kelley Shreve General Manager Lindberg/MPH Source: Lindberg/MPH
Our roller hearth furnaces are designed to meet the need for accurate, consistent, and efficient processing of heavy workloads. Features include a sturdy roll design for smooth load motion, high-efficiency heating systems for rapid heat transfer, integrated control systems for accuracy of operation and ease of troubleshooting, and material handling systems that simplify operation. Together, these features provide furnaces that will make operations more competitive.
How Is Your Roller Hearth System Unique?
What separates Lindberg/MPH from competitors is our ability to take standard designs and customize them so they are tailor-suited to meet the exact client specifications and floor plans.
Extensive experience in ultra-clean heat treating helped us improve roller hearth equipment as well. Traditionally designed furnaces have transfer sections open to air, which allows rapid heat loss and causes scaling or discoloration of the work. Our proven design shields the work with a directed flow of protective atmosphere through double-door transfer sections. This also ensures isolation of furnace zones that must not be cross-contaminated. An independent, high-speed roll system minimizes transfer time and heat loss. The sight-ports allow direct viewing of work-in-process for easy troubleshooting. The result is clean, consistent work.
What Are Best Practices for Training In-House Operators on Roller Hearth Annealing?
Lindberg/MPH offers complete installation packages which include installation, startup, and training. In-house operators are fully trained on all aspects of operations while our service technician is present.
What Are the Furnace’s Operational Advantages?
Our roller hearth furnaces combine the latest technology in process controls, atmosphere systems, and material handling systems. These furnaces are designed to carry very heavy workloads at high production rates at the lowest possible operating cost. Other advantages are that a roller hearth can be designed to run a multitude of different processes as required.
What Is the Most Common Heating Method?
Roller hearth furnaces can be supplied with either gas fired or electric heating. Gas fired Single End Recuperated Tubes (SERT) provide economical, rapid heating. Electric heating offers reliable, low-maintenance operation using elements tailored to atmosphere application.
What Are the Challenges in Operating This Type of Furnace?
Annealing produces
parts with reduced
hardness and a uniform
microstructure as a
preparation for further
processing. The furnace
has a high-heat section
followed by a controlled
cooling module.
Endothermic, Exothermic,
and nitrogen-methanol
atmospheres are typically
used.
A challenge for this type of furnace is proper maintenance. Operators should manage this challenge by monitoring the preventative maintenance (PM) features and indicators that are available. Setting in place and following a regular PM schedule is going to help ensure the equipment operates dependably and problem free.
Skuld LLC announced that they had purchased the site belonging to the former Champion Foundry in Piqua, Ohio, a gray and iron foundry that had closed in March 2017. The company will continue to be focused on innovation in the metals industry, serving their clients through a number of innovations related to novel materials and manufacturing technologies.
The four buildings with nearly 32,000 square feet of space are being refurbished to be capable of casting a wide range of ferrous metals (gray, ductile iron, steels) and nonferrous metals (aluminum, brass, bronze, copper, nickel alloys). The plant will initially have 3,000 tons of capacity but plans are in place to expand to ten times that capacity in the next few years.
Skuld will be installing machining, foam blowing, a printer farm, and heat treating, adding to their current 5 small heat treat furnaces and adding to their operations, which primarily consist of lost foam casting. The new installations will aid the company as they serve the defense, tooling, and heavy equipment industries. They are also beginning to target production of heat treat fixtures and baskets.
Sarah Jordan, CEO, Skuld LLC
Production at the new site is scheduled to begin in April 2024. Sarah Jordan, CEO of Skuld LLC, commented, "Skuld is looking forward to getting our induction melting furnaces installed so that we can produce higher temperature iron, steel, and nickel alloy castings." She continued, "many [heat treaters] have custom furnace components and fixtures that require high temperature metals. These parts can have extremely long lead times, sometimes over a year, which is a problem if they are stocked out." By using their new tooling free processes, Jordan says that they can help clients drive lead times down to less than a month, if not a day for emergency spares.
Skuld is a company founded by two metallurgical engineers, Mark DeBruin and Sarah Jordan, with ties to the heat treat industry. DeBruin is the former CTO of Thermal Process Holdings. Jordan formerly worked in heat treating at Timken and Commercial Metals and was a staff engineer for Nadcap heat treat.
The full press release from Skuld LLC is available upon request.
Heat Treat Today offers News Chatter, a feature highlighting representative moves, transactions, and kudos from around the industry. Enjoy these 34 news items, originally featured in the November and December print magazines.
Equipment Chatter
UPC-Marathon, a Nitrex company, commissioned an endothermic gas generator for a major automotive manufacturer in Brazil.
SECO/WARWICK will supply a Vector® vacuum furnace to a South American international manufacturer of weapons and military equipment.
Stahl Gerlafingen ordered from Danieli a K-Weld machine as well as a 2-MW Automation Q-Heat-system.
NITREX has installed a second set of nitriding/nitrocarburizing systems for a European hydraulics manufacturer.
An AQUAVAIRE Q3300H furnace from Algas-SDI is ready for shipment. This equipment is a gas-fired water bath vaporizer that converts liquefied petroleum gas into superheated vapor at a balanced pressure.
A vertical vacuum furnace from SECO/ WARWICK is heading to a company that provides repair and maintenance services for jet engines.
Turkish heat treater Reymak Makine As has integrated a Nitrex nitriding/ nitrocarburizing system.
Tratamientos Termicos Avanzados (TTA), a leader in plasma nitriding services for steel, recently received their first vacuum furnace from Ipsen. The Turbo2 Treater was shipped to their facility located in Monterrey, Mexico.
Endo generator for automotive manufacturerNew systems for Stahl GerlafingenAQUAVAIRE Q3300H
Company and Personnel Chatter
SAMPE North America announced LaNetra Clayton Tate, Ph.D. as the new vice president; Sarah Cox as the new president; and Daren Davis as the new secretary for the 2023–2024 term.
Donald Crist has been promoted to director of Global Sales at RoMan Manufacturing, Inc.
AFC-Holcroft announced a partnership with Sanken Sangyo, a Japan-based company in the thermal processing equipment industry
Partners Outokumpu and SMS group GmbH inaugurated a metal powder atomization plant in the presence of Minister President Hendrik Wüst.
Turgay Ozan started his new additional role as the president and regional manager of Pfeiffer Vacuum in North America.
Vamshi Vardhan Rapole has joined Danieli Group as a graduate engineer trainee.
Sheffield Forgemasters appointed Amy Grey as the chief financial officer.
Michel Siemon has been appointed CEO of Primobius, the lithium-ion battery recycling joint venture between SMS group GmbH and Neometals Ltd.
Bobbi Warren has been promoted to chief financial officer at RoMan Manufacturing, Inc.
Sheffield Forgemasters has announced the signing of a five-year contract renewal with Harsco Environmental.
SMS group GmbH and Steel Authority of India Limited (SAIL) have joined forces in a memorandum of understanding aimed at decarbonizing steel production in SAIL’s integrated steel plants.
Mark Przybylski started a new position as material handler of Manufacturing at Retech, a SECO/WARWICK Company.
SMS group GmbH welcomed Orascom Construction PLC to conclude the agreement signing of an alliance to help with future projects.
Thermal-Vac Arizona has announced the opening of a new Chino Valley, CA, shop for brazing, heat treating, testing, and machining services.
Hydro is set to install solar power at its extrusion factories in Sweden.
Mark Hemsath becomes the new president of Nitrex Turnkey Systems.
Joseph Scala of Leybold USA, Inc. wins Lifetime Achievement award for outstanding lifetime philanthropy after being named regional sales manager of VTS-Midwest for Leybold.
Nitrex and Linde renewed heat treating-focused joint marketing agreement and expansion into Europe.
Pfeiffer Vacuum’s President and Regional Manager,
Turgay Ozan AFC-Holcroft announced a partnership with
Sanken Sangyo, a Japan-based company in the
thermal processing equipment industry.A big year for Joseph Scala
Kudos Chatter
The GTS Mexico team completed a successful ISO/IEC 17025 audit with their accrediting entity.
The Driven to Reach Excellence and Academic Achievement for Males (DREAAM) program in Champaign, Illinois, toured Wirco, Inc.’s Champaign, Illinois, foundry.
SAMPE North America Board of Directors announced that Tim Shaughnessy, president and CEO of Rapid Cure Technologies, has been selected as the SAMPE 2023 Distinguished Service Award recipient. They also announced that Dr. Scott Beckwith, a renowned expert in the field of Materials Science, has been named the recipient of the prestigious Mort Kushner Lifetime Achievement Award.
After a 25-year career, Paulo’s heat treat manager in Murfreesboro, TN, Dave Lee, has retired.
Dan Essenmacher retired from AFC-Holcroft after 28 years with the company.
Paulo celebrates 80 years of heat treating history.
Bill Gasbarre, co-founder of Gasbarre Products, Inc., retired after 50 years.
Ipsen celebrates 75 years in Cherry Valley, IL, with a ceremony emceed by Heat Treat Today publisher, Doug Glenn.
Retirement of Paulo’s Dave LeeDoug Glenn with Patrick McKenna, president &
CEO of Ipsen USAStaff of the GTS Coahuila
Find Heat Treating Products And Services When You Search On Heat Treat Buyers Guide.com
This informative feature was contributed by CENOS, a simulation software developer. Read on to learn about how 3D printing is revolutionizing the heat treat world, particularly in the production of copper coils.
3D printing, also known as “additive manufacturing,” is a hot topic now as it broadens possibilities for on-demand and customized products, even with complex geometries. It eliminates the need for welding, soldering, bending, and similar steps in coil design as 3D printers build the object in one piece and in the exact shape as drawn in CAD.
(source: PROTIQ)
“3D printing unleashes design opportunities for induction coils, while 3D simulation software allows validating design performance. . . . We believe that 3D printing of copper will grow even more in significance for coil production, and possibly even become a part of the conventional manufacturing process,” said Max Wissing, Development Engineer at PROTIQ.
Currently additive manufacturing is widely used for steel parts, and for a long time printing machines were not able to print pure copper items. But now the technology has developed, and since the second half of 2019, it’s possible to print on demand 100% pure copper coils. Some companies with notable success offering this innovation are PROTIQ and GH Induction.
Main Benefits Simulations Enable Together with 3D Printing:
freedom of design
optimized geometry
more homogeneous heating
lower lead time
less material waste
cost reduction
3D Printed Copper Comparison:
RS-cooper
Pure copper
Electrical conductivity: 50 MS/m
Electrical conductivity 58 MS/m
Elongation at break: 25%
100% IACS
Improved strength for high loads
Elongation at break: 50%
Tensile strength: 230 Mpa
Tensile strength: 220 Mpa
Yield strength: 180 Mpa
Yield strength: 125 Mpa
Density: 98%
Density: 99.8%
Fewer Man-Hours, Faster Processes
Coils are a critical part of induction heat treatments as they must be replaced from time to time due to deterioration. This interrupts production and requires several man-hours for recalibration. In comparison to conventional manufacturing, 3D printing induction coils offer great benefits.
First, additive manufacturing provides better reproducibility and higher accuracy compared to the manual bending, which reduces necessary recalibration times. Second, it allows lower cost and faster production of inductors. Finally, using numerical simulation methods, the coil’s heat pattern is precisely predicted and visualized, helping optimize inductor geometry. This allows for creating a perfect coil with the first prototype.
Simulation and 3D Printing Process Illustration:
(source: PROTIQ)
Simulations as the Enabling Factor for Coil Durability
Simulations allow full freedom of design and point out places for improvement in producing a more efficient coil production process. 3D printers build objects layer upon layer, allowing them to make even complex geometries in one piece without soldering. Simulation of the design process allows predicting coil heating, which altogether results in a longer coil lifetime. Because there is no need to bend or join parts together with heat treatment, this also allows for eliminating some intermediate steps of the supply chain. Another notable benefit is that the lifetime of 3D printed coils can exceed conventionally manufactured copper coils up to two times, as reported by PROTIQ’s automotive industry clients.
Currently there are only a few copper coil printing companies because the material is not easily processed in additive manufacturing.
Comparison of maximum copper coil dimension as a single piece:
PROTIQ
GH Induction
Length: 250mm
Length: 200mm
Width: 250mm
Width: 200mm
Height: 300mm
Height: 100mm
The possible size of the printed coils varies between really small ones, measuring only a few millimeters, and bigger shapes that are used in the automobile industry. Coils that exceed the maximum printable dimensions can be joined together afterward via welding or brazing without problems.
Regarding the time, copper coils can be printed within a few days. Compared to the conventional way, which takes up to several weeks, this method enables fast-paced product tests and generates flexibility for the customer due to shorter delivery times.
3D Printing Future Forecast
GlobeNewswire market research shows that the global 3D printing metals market is estimated at USD $774 million in 2019 and is projected to reach USD $3,159 million in revenue by 2024. This suggests we will see even more and bigger 3D printed metal parts.
In a greater perspective, Boeing is demonstrating an impressive point that additive manufacturing currently has no limits. Boeing’s GE9X engines are now fully 3D printed, combining more than 300 engine parts into just seven 3D printed components.
Taking into consideration all of the benefits listed above, one has to wonder whether additive manufacturing will become the norm in the coming decades in many of the traditional manufacturing processes.
