Welcome to another Technical Tuesday for 18 hard-hitting resources to use at your heat treat shop. These include quick tables, data sets, and videos/downloadable reports covering a range of heat treat topics from case hardening and thermocouples to HIPing and powder metallurgy.
Defining Terms: Tables and Lists
Table #3 Suggested Tests and Frequencies for a Polymer Quench Solution (in article here)
Case Hardening Process Equipment Considerations (bottom of the article here)
Two simulations of a moving billet through heating systems (in article here)
Fourier’s Law of Heat Conduction (in article here)
Webinar on Parts Washing (link to full webinar at the top of the review article here)
Materials 101 Series from Mega Mechatronics, Part 4, Heat Treatment/Hardening here
Heat Treat TV: Press-and-Sinter Powder Metallurgy here
BONUS: 39 Top Heat Treat Resources
Heat Treat Today is always on the hunt for cutting-edge heat treat technology, trends, and resources that will help our audience become better informed. To find the top resources being used in the industry, we asked your colleagues. Discover their go-to resources that help them to hone their skills in the 39 Top Heat Treat Resources on this page of the September print magazine.
A high-uniformity box furnace has been delivered to Soil Lab, a community-based workshop based in Chicago, as part of the 2021 Chicago Architecture Biennial. The furnace received a fast-track shipment of four weeks to be part of the biennial workshop program in which local community groups will experiment and gain knowledge of ceramic production and various processes.
TheL&L Special Furnace Co., Inc. Model XLE 3636 is a front-loading, refractory-lined box furnace and has an effective work zone of 34” wide by 34" high by 32" deep. There is a horizontal double pivot door with a safety power cutoff switch. A ceramic hearth and standoffs are provided as a workspace for various ceramics and ceramic-based products. Additionally, the furnace has a series of inlets on the side and an outlet on the top. These can be capped off when not in use to preserve heat, and can provide a "candling" effect where various ceramic byproducts can be removed from the furnace. Some of these byproducts can be corrosive and need to be removed from the system.
Pictured in the main image above: Soil Lab team photo, (L to R) Vester, Bruun, Martin, Ni Chathasaigh
A multi-unit modular pot furnace system has been set for an aerospace manufacturer in the U.S. to help the end user increase heat treat capacity.
Each of the four Lucifer Furnaces Model 2057 pot furnaces is connected to a single freestanding NEMA 1 control panel. Each furnace is heated electrically with 18 KW of power to heavy duty coiled elements in removable holders on all 4 side walls. Roof and side covers bolted to the frame of each furnace can be removed for easy service access.
The units are insulated with 5" of multi-layer insulation consisting of dry-fit hot face lightweight firebrick backed by cold face mineral wool. A vestibule at the top of each furnace reduces heat loss between the pot wall and firing chamber. Controls onboard include Honeywell DC3500 digital multiprogrammable cascade controllers which automatically interpret multiple thermocouple readings and adjust the inside/outside pot temperature to achieve the desired set point. Additional energy efficiency and power uniformity is maintained with SCR power units.
Happy Halloween! Instead of the spook, we wanted to give you something to celebrate this weekend the way YOU know how to: through heat treating. Whether you know a heat treater on a tight budget or your shop is ready to "try something new", we want to show you TWO uses of pumpkins for your shop this Fall.
Pumpkins as Furnaces
Pumpkins make great ovens. The orange gourds, commonly converted into jack-o-lanterns this late-October, have a proven degree of structural integrity that can maintain heat for one cycle.
This process works best for heat treating parts that need to be introduced to gaseous H2O during the cycle time.
As you can clearly see below, the pumpkin can serve as a "furnace" for special parts.
Dimensions: 11.5" outer diameter x 11" total height; heating chamber is 10.75" diameter x 10.25" height; wall thickness is 3/4"
Temperature: range from 0-450 degrees Fahrenheit lasting 1 cycle (max)
Materials: organic matter derived from Cucurbita pepo
Cycle times may vary depending on the size and quality of vessel. For the example used in this article, the cycle ranged from roughly 0.75-1.25 hours. Controls are not included.
Pumpkins don’t just make great furnaces, they are also parts to be heat treated. If it's slow on the shop floor this Fall, just take a lousy pumpkin from your doorstep and get to work!
While a pumpkin does have more prep involved, word has it this “part” is edible, too. Follow these steps when these parts come to your shop:
Be sure that the coating used for the part is of highest quality. Cinnamon, allspice, and a hint of salt with olive oil have the right chemical composition for this part.
When applying the coating, it is imperative to evenly distribute it across all parts in order to achieve consistent, predictable results.
I'll leave the heat treating to you, but I recommend an open flame furnace for these parts. In this instance, discoloration is to be expected, but this is typically what customers want to see. Bonus: No quenching or cleaning required.
Transfer parts to a cooling location.
For best results, heat treat parts in small batches.
Heat TreatToday publisher, Doug Glenn, sat down with heat treating specialist, Piotr Zawistowski, the managing director at SECO/VACUUM, to hear what he believes the future of heat treat holds. Karen Gantzer and Bethany Leone from Heat TreatToday also joined the conversation, recorded at the ASM Heat Treat Show 2021. In this episode, you’ll learn why Piotr believes LPC, automation, and predictive maintenance are the future of heat treat and how to get there.
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.
Bethany Leone (BL): Peter first shared how SECO/WARWICK was on a mission to actualize the future of heat treat.
Piotr Zawistowski (PZ): I think we are on a mission, that is, SECO/WARWICK and I. I think the future of heat treatment will be LPC for carburizing, and gas quenching for quenching instead of oil. I think the future is LPC and hydrogen quenching, to be honest. Right now, most of carburizing is done in a carburizing atmosphere, and most of the quenching, as I know it. I think that everything is moving in the vacuum direction, if you will, but we're not there yet. So, that's our mission, in general.
Members of Heat Treat Today sat down with Piotr Zawistowski, managing director of SECO/VACUUM, at the ASM Heat Treat Show 2021.
I think I showed you a graph with what is the difference in quenching between oil and gas. Right now, with 25 bar quenching, we are on the level of slow oil. To get there, we have to use helium, but it's expensive, it's not economical. We can go to hydrogen, which is the speed of oil and it's everywhere, it's cheap. I think this is the future.
BL: This idea that the future of heat treat will be LPC and gas quenching – specifically with hydrogen – means moving in the vacuum direction, as Peter noted. But how fast will this transition come, especially given safety concerns with the use of hydrogen as a quenchant?
PZ: Exactly, that is the concern right now. I think it will come, but we are far away from it. Anyway, we don't have to go to hydrogen immediately, but I think we should go to nitrogen for now. We have some solutions for that, and on top of that, I think we will go from regular carburizing to LPC. It's not easy for people to switch, so our mission is for us to try to convince people to switch to LPC. We would like to make it as easy as possible for them so that's why—maybe 20 years ago—we thought about starting. Because we had quenching and carburizing, we thought, let's maybe leave quenching the same and start with carburizing. So, we developed vacuum oil quench furnaces just to make it easier so they only have to change one thing at a time. But then, we thought, it's a leap for them anyway because those are different oils and it's a vacuum oil. So, right now, we're introducing a furnace with vacuum carburizing with the regular atmosphere is a quenching chamber in regular oils that all the heat treaters have known for years.
DG: This is the SuperIQ?
PZ: This is the SuperIQ. I don't want to make it commercial, but this is another step. If you look at our wall here, we have six different products and five of them are for carburizing. It starts with Vector. It can have carburizing but it doesn't have to be, but anyway, they all are connected with carburizing. I think the mission is to convince people and to switch, in the industry, from all the messy dangerous, open-fire furnaces to new, clean, better technology.
Piotr sharing SECO/WARWICK vision for the future of heat treating.
BL: As we just heard, these are big transitions. So, if the first step towards heat treat with LPC is for heat treaters to use atmosphere carburizing with oil quench, what are the next steps to move to a fully vacuum-based future?
PZ: Step number two is vacuum oil quench and step number three is vacuum carburizing or LPC and high pressure gas quench. That is the future, in my opinion, and with hydrogen.
BL: As a review, moving to LPC could look like, first, using a traditional vacuum furnace with atmosphere capabilities, then, heat treating with vacuum oil quench, and finally, heat treating with LPC and high pressure gas quench. If such a transition is appealing, it would be good know what the productivity improvements of LPC are. . .
PZ: So, it depends; there are a couple factors. First, we have to take into account what kind of a case that we're talking about. But, in general, I can tell you that the productivity increase should be 50%, or even 100%, or more.
DG: You can double the amount of product through in the same amount of time?
Piotr walks through challenges to overcome to achieve an LPC and hydrogen heat treat future.
PZ: Yes. And, it's just as simple with increasing the temperature, so we are not limited with low pressure carburizing with the temperature, whereas there is a limit that atmosphere carburizing can be done. So, we have a lot of possibilities here.
BL: So, a 50-100% increase in productivity and an increased temperature range comes along with low pressure carburizing, LPC. When considering LPC, there is the question of how traditional specification, which clearly state the necessity of atmosphere carburizing, can be compatible with this newer technology.
PZ: Yes, and those specs are changing.
DG: Is that going to be a hindrance?
PZ: Yes, it is right now, especially in aerospace. The automotive industry, they moved already to LPC, but aerospace we are trying to help to change those specs, and they are changing as we speak. A lot of those specs are still from the '80s, and there was no LPC back then. As you know, in aerospace, it is not easy to change a spec, but this is happening right now, as we speak.
DG: Are you guys involved with changes from Nadcap and all?
PZ: Yes, and we are involved in major aerospace players. We are doing tests for them and we are delivering them LPC furnaces. Some of them are still doing R&D, but this is a first step. With some of them, we are starting to see real production with LPC in aerospace, so we are getting there.
BL: To be sure, integrating the technical creation of specs by bringing heat treaters in touch with key end-users in the industry is necessary to have standards reflect effective heat treating techniques. Aside from standards, is there any resistance to adopting low pressure carburizing?
PZ: I think, people are afraid of what is new: atmospheric carburizing is very simple and it is well known, vacuum carburizing is something different. So, for atmosphere carburizing, it's only to control the potential in the furnace and time of carburizing. In vacuum carburizing, it's not that easy- you have to have a special simulator to create a recipe. People are afraid of it, but they shouldn't be because there is software. We have software that can make that recipe really easy and pretty quick. People are just afraid of something new.
SECO/WARWICK's SimVac
We have it [simulator] to create a recipe for LPC for the purpose of carburizing and we actually provide it. This is our own simulator and we provide it with the equipment so it's very, very easy.
BL: In addition to an aversion to the new and the changes that may be involved, folks have a real concern with distortion. Peter then addressed this concern. . .
PZ: High pressure gas quenching, in general, is better, but there are other methods. It is not only us, but we are all trying to limit the distortions; we cannot say “eliminate” because that is impossible, but we can try to limit the distortion and control the distortions. What we introduced to the market is our 4D quench technology, “fourth” dimension is that we rotate the part during quenching.
BL: While there is resistance that may be from outdated industry specs, a suspicion of the new, or technical concerns which the industry is continually addressing, Peter was sure note that there are, in fact, drivers that are encouraging heat treaters to move towards LPC.
PZ: I think, the driver is both productivity and safety. As an example, the [US] Biden administration just committed to reduce CO2 emission by 50% by the end of the decade. This is good technology and there is a lot of fuel to emission out of atmosphere carburizing, internal and external. But, there will be a push for climate change and CO2 emission. I think, it's not only mandates, but, I think, in Europe, for example, they have a lot of grant; there is a lot of government money you can get if you are reducing the CO2 emission. I think, for the heat treaters, it should be easy to capitalize on it. As I said, no CO2 emission on LPC. There is no emission at all. That is the beauty of the technology.
Kanthal notes the electric shift that is predominantly occurring in Europe
Find this article in the August 2021 digital edition
BL: Certainly, financial incentives to adopt “greener” technologies as well as personal desire to do so would be motivating. Is there anything about the heat treated parts cosmetically that would make LPC attractive?
PZ: Of course. And, you don't have to wash it after, which is great. It depends, as we still can have LPC and oil quench, you have to wash it, but if you can get to the gas quench, you've eliminated the wash part. They just look nice and shiny and bright. The color is better and you can eliminate washing.
BL: It is clear that LPC, one of the factors that plays into the future of heat treat as Peter envisions, has challenges and benefits for heat treaters to consider. Peter then talked about two additional factors for the future of heat treat: automation and predictive maintenance.
PZ: There are two other factors. One is automation, which is something big and it's more and more especially nowadays with the labor issue. But, it is to eliminate the human error part of it. On top of that, it is the traceability of the parts. More and more customers would like no operators and the machine has to run by itself. We have that—a full system of equipment. You just place the basket with parts, or several baskets, and then the robot takes it to the furnace, carburizes, quenches, tempers, washes and then it comes out, completely untouched. Robots are the automated loader. That is the direction.
Another is predictive maintenance, which is a big deal right now. By predictive maintenance, I mean that the system has to predict the failures or the downtimes. A lot of systems, which are available on the market are called “predictive maintenance”, but they are reactive. For example, they have sensors on the machine and if something breaks, it sends you an email message, or whatever. Our SECO/PREDICTIVE, which is our predictive maintenance, is based on an algorithm. The algorithm is written in such a way that the system learns on failures and the more equipment we have connected to it, the more data we have, like everything we have around us right now, all the Googles and Amazons and so on. I think this is the future, as well. So, everything has to be connected to one database to predict what will happen before it happens.
DG: Can you give me an example? Let's say you've got a high temperature fan inside a vacuum furnace. How would the SECO/PREDICTIVE or predictive maintenance work on that?
PZ: I think we would control the vibration on it. I think that's one way to do it. And, at a certain level, it would send a signal – "Watch out! - you are about to have a problem". It is better to do it that way because, then, there is time to order a replacement or schedule something so it will not break. But, the goal is to predict the failure before it happens.
BL: With thoughts of LPC, automation, and predictive maintenance on our minds, we then walked over to a display of various furnaces to see how SECO/VACUUM applied these insights to their own furnaces. Peter began with the Vector, a versatile high pressure gas quench furnace.
PZ: This is a single chamber, multipurpose furnace. It is for LPC carburizing and high pressure gas quenching. This is the main furnace and, I think, 70% of what we sell. Maybe this is, like 50%.
Then 20% are the vacuum oil quench furnaces. The vacuum oil quench furnaces heat processing chambers are the same as the Vector but then we can quench it in oil or we can have three chambers that can be continuous production or you can have oil quench on one side and high pressure gas quench on the other side. We call it CaseMaster Evolution. This is our middle step. As I said, our goal is to go for LPC.
But, then, there is another one, the new baby in the family. [Peter then gestures to, what they call, the Super IQ vacuum furnace.]
For people, it was not easy to make a switch, so this is like a hybrid. The processing chamber is vacuum carburizing but the quenching chamber is like a traditional atmosphere quench. It is like a pure replacement: you can take one out and put this guy in. You have all the benefits from low pressure carburizing but you operate mainly like an old and traditional furnace. This is to make it easier in the transition.
BL: After learning how certain furnace designs can be helpful to heat treaters who have different processing needs or who are trying to convert to LPC, we then moved to see how LPC is being brought to pit-furnace size loads.
PZ: This is another one, another tool in our mission, I would say. This is a pit carburizing furnace but with LPC. Right now, for big, heavy parts, they are carburizing atmosphere in pit furnaces and then they open the furnace and they just transfer it with a crane to an oil tank. This is basically the same, but the pit furnace is with LPC. There is nothing like this on the market right now.
We are trying to bring the LPC advantages to big parts and pit-style carburizers, as well.
BL: From LPC for large loads, we ended our tour with an LPC furnace with an interesting way to maintain traceability.
PZ: This is a single-piece carburizing furnace which we talked about.
So “CaseMaster”, which was the name of our traditional integral quench carburizing furnace in the past, we no longer do. Right now, if we have an RFQ for atmosphere carburizer, we go with LPC.
Thank yous from the group.
Doug Glenn
Publisher Heat TreatToday
To find other Heat Treat Radio episodes, go to www.heattreattoday.com/radio and look in the list of Heat Treat Radio episodes listed.
Heat treat solution manufacturer in Roseville, MI has been acquired by Kolene Corporation, a global leader of custom-designed and engineered molten salt bath equipment and specialty chemical formulations.
Upton Industries, Inc.
"We are proud to carry on Upton's strong brand and legacy as a part of Kolene Corporation as we move forward," commented Roger L. Shoemaker, chairman & CEO of the company.
Founded in 1937, Upton Industries, Inc. design and manufacture thermal processing systems in the metal heat treating industry. They apply their Engineered Thermal Solutions methodology to heat treat equipment including box type, car bottom, lift-off and specialty furnaces that utilize either electric heating or gas-fired systems.
Kolene will maintain both its Detroit headquarters location and the Upton Roseville location, which will be home to all Kolene’s manufacturing and fabrication. Bringing the two companies together will give the new company 50,000 sq. ft. of manufacturing, fabrication, and commercial processing capabilities.
W. Scott Schilling President Kolene Corporation
"After thoroughly evaluating Upton’s capabilities," said W. Scott Schilling, president of Kolene, "it was apparent that there are tremendous synergies between the two companies. Capitalizing on these synergies will allow [the company] to expand into applications and revenue segments where we have not historically been. [We] will also have the ability to become more vertically integrated due to Upton’s manufacturing and fabrications capabilities, which will allow us to strengthen our overall margins."
In its 82nd year, Detroit-based Kolene Corporation provides custom-designed and engineered equipment, specialized chemical formulations, and processes for cleaning and conditioning metal surfaces. Currently, their products are used worldwide for casting cleaning, alloy descaling, coatings removal, engine rebuild and other demanding automotive, industrial, and military applications.
Designing ultra-efficient aircraft, lightweight automobiles, and modern power generation systems requires new materials with higher strength-to-weight ratios that can withstand higher operating temperatures for longer periods of time. These lighter weight, heat-tolerant materials help increase fuel efficiency and save energy, but characterizing these materials poses several challenges.
In this Technical Tuesday article, Dr. Erik Schwarzkopf, staff scientist at MTS Systems, will help you discover solutions to these challenges that will improve high-temperature testing of composites. This is the special focus article that appears in the Heat TreatToday November 2021 Vacuum Heat Treat Systems print edition. Return to our digital editions archive on Monday November 15, 2021 to access the entire print edition online!
Dr. Erik Schwarzkopf Staff Scientist at MTS Systems
Testing at high temperatures can be complicated because “elevated temperature” means different things to different researchers. In general, there are three distinct temperature ranges for materials that have the highest strength-to-weight ratios. The first is for polymer matrix composites, or PMCs, from 392°F to 932°F (200°C to 500°C). The second is for metals, from 1472°F to 1832°F (800°C to 1000°C). The third is for ceramic matrix composites, or CMCs, which are tested up to 2732°F (1500°C). In each range, there are tradeoffs that test engineers need to consider in order to measure material properties at elevated temperatures and acquire high-quality results.
Problems arise when dealing with objects that need to touch the specimen or be near the specimen, such as grips, extensometers, furnaces, and chambers. The problems tend to be systemic, so solving an issue with one component tends to raise issues with another component.
In many cases, these issues start with specimen geometry. For example, PMC and CMC specimens are flat, and they cannot be grabbed in the same way as a round, threaded, or button-head metallic specimen. For gripping PMCs, cost-effective and easy-to-use hydraulic wedge grips are a good choice. Hydraulic wedges can apply consistent pressure to protect the fragile PMC specimen fibers from crushing and are able to maintain the correct pressure even as the chamber and wedge head heat up. These grips are relatively large, so they are often paired with a larger environmental chamber. The environmental chamber is typically larger than the furnaces required for higher temperature tests, but the thermal mass of the grips and chamber leads to very stable temperatures.
However, the larger chamber makes it difficult to use contacting extensometers, which test engineers would normally use in these applications. With a smaller chamber, you can situate the sensing technology outside the chamber and allow it to translate motion from the contact arm; but with a larger chamber, you cannot effectively translate that motion outside the chamber because the arm gets too long. The extensometer needs to be inside the chamber — but the elevated temperature damages the sensitive electronics.
"One of the best ways to increase high-temperature testing success is to work with a solution provider who understands the entire test."
One way to solve this issue with contacting extensometers is to use video extensometry and digital image correlation. These non-contacting strain measurement devices can be located outside the chamber, away from the heat that would damage other extensometers. A chamber with a window will let you look inside and measure motion in real-time. But this solution is not without its complications, either. You need a light inside the chamber to illuminate the specimen for the camera, and at some temperatures, the specimen’s illumination (or blackbody radiation) reduces the contrast and accuracy of video extensometry. You can mitigate these problems by using blue LEDs to illuminate the chamber and optical filtering to minimize blackbody effects and enhance contrast.
PMCs and CMCs are typically engineered as flat structural components, but given the gripping challenges presented by flat specimens, some people have wondered why we cannot just use round specimens instead. Even with metals, it is often not possible to obtain a large enough portion of the material to make a round specimen, especially if the goal is to test material that has been in service. Sometimes, a small specimen is extracted from a larger component — specifically, turbine blades from jet engines. The blades that see the hottest application temperatures are grown from single crystal seeds with cooling holes to let air through. These intricately shaped blades do not have enough bulk to create a round specimen. Also, when the interdendritic spacing of a single crystal is similar to the specimen dimensions, the specimen might act quite differently than a bulk, round specimen.
Gripping specimens in high-temperature applications remains a challenge. A test engineer would normally use high-temperature grips for most high-temperature applications. But the CMC testing temperature range exceeds 1832°F (1000°C) and these grips would start to lose strength. Ideally, the grip should be as hot as possible to minimize the gradient, just not so hot that the grip itself starts to get soft. If a specimen is long enough, cold grips could be used. But some specimens cannot be made long enough, for the same reasons they cannot be made round. Even if cold grips are used, larger gradients are then introduced, which means more tests need to be run due to the variations in those gradients, and that adds expense.
To address these challenges in the highest temperature ranges, look for a grip that can be actively cooled in two different ways, depending on what temperature range is required. These versatile grips can be placed in an area of the furnace that is relatively less hot than the center zone. If the center zone is 2192°F (1200°C), the top and bottom portions are closer to 1832°F (1000°C). With active cooling, the grip can stay in the cooler part of the chamber and still hold the specimen in place with an acceptable gradient. For testing metals up to 1832°F (1000°C), you can use a grip that is moderately cooled. For testing CMCs up to 2732°F (1500°C), look for a grip that is aggressively cooled.
One of the best ways to increase high-temperature testing success is to work with a solution provider who understands the entire test. Many labs attempt to build high-temperature testing solutions by assembling components from different providers. Unfortunately, the interdependencies and tradeoff s are too entangled. The extensometry expert may not understand how to make their offering work through a window or inside of a chamber. Grip experts may be able to make cold grips work, but the gradient is so large that it calls the test results into question. Find a provider that can offer the systems integration expertise you need to reduce testing variability, allowing you to run fewer tests and get accurate results.
About the Author: With more than 30 years of experience in materials testing, metallurgy, and system engineering, MTS Systems staff scientist Dr. Erik Schwarzkopf frequently shares his testing expertise in technical articles and conference presentations.
For more information: Contact Dr. Schwarzkopf at erik.schwarzkopf@mts.com
Want a free tip? Check out this read of some of the top 101 Heat TreatTips that heat treating professionals submitted over the last three years. These handy technical words of wisdom will keep your furnaces in optimum operation and keep you in compliance. If you want more, search for “101 heat treat tips” on the website! This grab bag of 10 tips focuses on how to keep your heat treating costs down, either by maintenance strategies or product and process decisions.
By the way, Heat TreatToday introduced Heat TreatResources this year; this is a feature you can use when you’re at the plant or on the road. Check out the digital edition of the September Tradeshow magazine to check it out yourself!
Oxygen Analysis as a Cost Saver
Investing in and using an oxygen analyzer on a regular basis can provide significant fuel cost savings and, at the same time, optimize uniformity and maximize capacity.
(Super Systems, Inc.)
New Diffusion Pump Technology Increases Production Output
Gain immediate positive net cash flow with a lease to own finance option by upgrading your diffusion pumps with the new immersion heater technology. The new style heater will extend oil life and reduce energy consumption. New heater technology can increase production by eliminating the need of dropping your pump every time you change oil for faster maintenance turn around. Drop in place pump design with improved performance.
(Leybold Vacuum USA)
TZM Moly Alloy for Structural Vacuum Furnace Components
For over 30 years, there has been a molybdenum alloy called TZM (Moly-0.5%Ti-0.1%Zr) which is far superior to pure molybdenum in vacuum furnace structural applications. TZM is slightly more expensive than pure moly, so OEM furnace companies use pure moly to keep their costs down for competitive reasons. But they could be offering it as an option for their buyers. Pure molybdenum metal undergoes recrystallization at temperatures as low as 2000°F. The recrystallized structure is very brittle at the grain boundaries, resulting in a structural component that also is very brittle. If you have a vacuum furnace with moly components, you have undoubtedly seen this with older parts. TZM alloy, however, does not recrystallize until around 2500°F, and even then it does not exhibit the brittle behavior of pure moly, because the recrystallized grain size is still very fine. TZM is also stronger than pure moly, as much as 3 to 4 times the strength at temperatures above 2000°F. For a 10-15% premium in cost, you can dramatically extend the life of your moly structural components in your furnaces.
(Grammer Vacuum Technologies)
How Much Lost Money Flows Through the Walls of Your Furnace
In a strict sense, heat flows through the insulating lining of your furnace wall: the lower the outside temperature in the furnace shell, the less heat is lost and, consequently, less money.
For example, an outside temperature on the oven shell of 160°F (71°C) equals a heat loss of approximately 190 BTU/hr ft2, just multiply this number by the square footage of the entire outside surface of the oven. A well-designed and well-maintained insulation can reduce the outside temperature of the shell, say 120°F (49°C), and heat losses would be close to 100 BTU/hr ft2, that’s 90% more heat lost and therefore fuel.
So, my Tip for today is: “Let’s go for the basics that don’t change, and it will always give good results.” By the way, how many furnaces are there in your plant and how many square feet do their surfaces add up to?
(Carrasco Hornos)
Never Go Cheap on These Two Things
There are 2 things in life you should never go cheap on: Toilet paper and combustion equipment! When upgrading or looking at new systems, spend the money to do it right. Designing on the cheap will only lead to operational and maintenance headaches. And trying to reuse the ancient artifacts when upgrading just to save a buck will cost you 10x that down the road. You don’t have to break your budget to do a quality job!
(Bloom Engineering Co., Inc.)
Don’t Be Cheap. Buy an IR Camera.
IR cameras have come way down in price—for a thousand dollars, you can have x-ray vision and see furnace insulation problems before they cause major problems—also a great diagnostic tool for motors, circuit breakers, etc. (And you can spot deer in the dark!)
(Combustion Innovations)
4 Reasons Not to Overlook Combustion System Maintenance
Anyone who has operated a direct fired furnace, especially one that relies on pressure balance ratio regulators for ratio control, knows that regular tuning is needed to keep the process running with the proper air to fuel ratio.
Here are 4 reasons not to skip regular combustion system tuning:
It can cost you money: Operating with more air than needed will reduce your furnaces efficiency and require you to burn more fuel. Conversely, operating air deficient, unless necessary for the process, results in unburned fuel being released with the exhaust gasses. In most cases the unburned fuel going up your stack is energy that you paid for.
It can decrease product quality and yield: For many ferrous metals too much excess air will result in excess scale formation at high processing temperatures. On the contrary other materials such as titanium need to be processed with excess air to prevent Hydrogen pickup.
It can reduce your furnace’s reliability: The burners on your direct fired furnace will have a defined range of acceptable air to fuel ratios for proper operation. If your system wanders outside of this range, which can be fairly tight with today’s ultra-low NOx burners, you could start to see flame failures that result in unplanned shutdowns.
It can be a safety hazard: Apart from the possibility of causing burner instability, running with too little air will increase CO emissions. Unless your furnace is designed to safety exhaust CO you could end up exposing personnel working near your furnace to this deadly gas.
(Bloom Engineering Co., Inc.)
Inspection Mistakes That Cost
Rockwell hardness testing requires adherence to strict procedures for accurate results. Try this exercise to prove the importance of proper test procedures.
A certified Rc 54.3 +/- 1 test block was tested three times and the average of the readings was Rc 54 utilizing a flat anvil. Water was put on the anvil under the test block and the next three readings averaged Rc 52.1.
Why is it so important that samples are clean, dry, and properly prepared?
If your process test samples are actually one point above the high spec limit but you are reading two points lower, you will ship hard parts that your customer can reject.
If your process test samples are one point above the low spec limit but you are reading two points lower, you may reprocess parts that are actually within specification.
It is imperative that your personnel are trained in proper sample preparation and hardness testing procedures to maximize your quality results and minimize reprocessing.
(Young Metallurgical Consulting)
Question the Spec! Save Money!
Before you specify a heat treatment, stop and consider your options. Rather than reusing an old specification, ask the design engineer to determine the stress profile, and base the hardness or case depth on real stress data. Is this complicated? Maybe. But especially for carburizing, why pay for more depth than you need, and why take the risk of inadequate strength? The 21st century is here. We have ways to help with the math. Let’s move beyond guess and test engineering methodology.
(Debbie Aliya)
The Right Furnace Atmospheres Will Pay Dividends
Save money on your furnace atmospheres by employing the driest and leanest furnace atmosphere blends possible. Furnace atmospheres are a compromise between keeping it simple and supplying exactly the atmosphere to meet the unique requirements of each material processed. Organizations have different priorities when it comes to atmospheres—heat treat specialists may want to be able to run as many different materials as possible using a limited array of atmosphere types, while captive heat treating operations often want exactly the atmosphere approach to maximize the benefits for their specific processes/products.
The dewpoint (water content) of the atmosphere in the furnace is a key factor in its performance. At high temperatures, water in the atmosphere can break down, releasing oxygen that can cause oxidation. You must maintain a high degree of reducing potential to achieve the surface finish and processing results desired. If the furnace atmosphere gas is wet, you’ll need a gas blend richer with hydrogen than you would if your atmosphere blend had a lower dewpoint (less water vapor content). Since hydrogen costs 10 times more than nitrogen, it is more economical to run a leaner atmosphere than a richer atmosphere. By running the driest atmosphere blend possible, you may find that you can lean down your atmosphere (consistent with the metallurgical needs of your product/process) by reducing the proportion of hydrogen and increasing the nitrogen. In doing so, you may recognize meaningful savings.
Check your furnace atmosphere raw materials and process and obtain the driest atmosphere possible. Control your atmosphere dewpoint by adding humidity as needed to the driest starting blend possible rather than accepting a wet atmosphere and trying to process your parts. You’ll achieve the best compromise of excellent results at the lowest cost.
(Nel Hydrogen)
Check out these magazines to see where these tips were first featured:
Sometimes our editors find items that are not exactly "heat treat" but do deal with interesting developments in one of our key markets: aerospace, automotive, medical, energy, or general manufacturing. To celebrate getting to the "fringe" of the weekend, Heat Treat Today presents today’s Heat TreatFringe Fridaybest of the web article evaluating how your jobs may look a little different as general manufacturing adopts Industry 4.0 trends.
A question this article asks -- and you should, too -- is "What talent and skills do manufacturers need in order to succeed in the factory of the future?" With interconnected digital and physical developments through internet technology, heat treaters may fear that a "robot" will replace them. Armed with this article, you'll be able to identify what skills are needed for the future of five manufacturing roles: production planner, industrial engineer, operator, line leader, and quality engineer.
An excerpt:
[blockquote author="" style="1"]The smart factory of the future will perfectly blend human capabilities with technology. Manufacturers can get ahead now by understanding how critical manufacturing roles will evolve and how to hire, train and upskill for these roles. Getting it right in talent development will ultimately separate the leaders from the laggards.[/blockquote]
If you are interested in how the heat treating industry is affected by artificial intelligence (AI), the industrial internet of things (IIoT), and other subjects related to Industry 4.0, check out this article. Here's an excerpt:
"According to Aymeric Goldsteinas, project development manager at Ipsen, customers are becoming more willing to implement Ipsen’s Industry 4.0 endeavors, even cloud-based solutions, a willingness that was not present just one decade ago. So how is the heat treat market responding? We asked suppliers how they implemented Industry 4.0. . ."
A new resource created and run by the Metal Treating Institute (MTI) offers tools to those seeking a career in the heat treat industry. Review some of these insightful videos, resources for young professionals, and a network to further your heat treating capabilities below!
There’s a new kid on the block trying to get young people to join the heat treat “club”. A product of the Metal Treating Institute (MTI), this new website called HeatTreatCareers.com features site tours, first-hand testimonials, and orientation videos for anyone seeking to understand the world of heat treat. These handy videos and brief articles also include resources for heat treaters who are looking to outsource some of their processes or for equipment solutions as they update and expand their offerings.
Calling All Young Industry Professionals
If you know someone who is new to heat treat – maybe a potential hire, a new hire, or a colleague who is looking into joining the field – they must check out this website. For young professionals, this website provides specific direction, explains what heat treating is, and how to pursue a career in it.
Three resources that HeatTreatCareers.com offers are:
“What is Heat Treating?” video (see below)
Searchable directory for heat treaters in your state (or by name)
MTI YES Management Training Program
There are more training opportunities available here to increase professional management and/or technical knowledge pertinent for the heat treating industry.
But perhaps the most import aspect of this website is we get to hear from real heat treaters how this industry is more than a job. Be it the relationships or the day-to-day challenges that inspire creative thinking, it can be hard to locate one specific reason why anyone would enter our obscure industry. The video below makes a great case for this.
More Resources to Increase Heat Treat Capacity
For the young-at-heart and those who are ALWAYS looking to try something new, there are several resources for you, too. The first is a RFP form that allows you to propose a wild heat treat project to a network of commercial heat treaters to help you complete the project. This feature is part of the CallMTI.com resource, which connects you with MTI members from 40 states and eight countries, who are open for consultation.
Another resource is the “Why Outsource” tab that you can navigate to after clicking the Featured Plant Tours page. This resource helps you identify which heat treating challenges you’d prefer to overcome via outsourcing. Those challenges could include:
finding qualified good-workers
meeting OSHA safety requirements
funding needed equipment
continuing on-going maintenance
Of course, feel free to use that career finder that we mentioned above. Who doesn’t like a new challenge?
Bottom line: The website has something to offer everyone, especially if you are looking for a change or a challenge. And, by the way, who can visit the site and leave feeling unimpressed. . .?
Welcome to another Technical Tuesday for 18 hard-hitting resources to use at your heat treat shop. These include quick tables, data sets, and videos/downloadable reports covering a range of heat treat topics from case hardening and thermocouples to HIPing and powder metallurgy.
