Let’s discover new tricks and old tips on how to best serve air and atmosphere furnace systems. In this series, Heat Treat Today compiles top tips from experts around the industry for optimal furnace maintenance, inspection, combustion, data recording, testing, and more. Part 2, today's tips, examines burner and flame safety. Look back to Part 1 here for tips on seals and leaks.
This Technical Tuesday article is compiled from tips in Heat Treat Today's February Air & Atmosphere Furnace Systems print edition. If you have any tips of your own about air and atmosphere furnaces, our editors would be interested in sharing them online at www.heattreattoday.com. Email Bethany Leone at bethany@heattreattoday.com with your own ideas!
1. Operating with a Multiple Burner System
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If a furnace or oven has a multiple burner combustion system with only one valve train, a multi-burner combustion safeguard should be used. This ensures that if one burner fails, they all go out.
Source: Bruce Yates, "Ten Tips for Safeguarding Combustion Processes"
#multiburner #combustion #safety
2. Regularly Inspect Retort Alloys
Source: Nitrex
Retort alloys must be inspected on a regular basis. Hot spots can be identified by bulges. Plastic deformation occurs due to overheating, causing the hotter section to bulge because it is surrounded by stronger metal. Inspect your retorts or radiant tubes for deformations. In addition, constant thermal cycling can cause problems with some alloys. Look for cracks in welds or near welds. Some leak detection methods can also detect alloy issues or overheating.
Localized overheating could indicate a problem with the burner or the heating element. Early detection and correction can save you a lot of money on expensive alloys.
Flame supervision may be defined as the detection of the presence or absence of flame. If a flame is present during the intended combustion period, the supervisory system will allow a fuel flow to feed combustion. If the absence of flame is detected, the fuel valves are de-energized.
This basic definition does not consider the hazard potential during startup or ignition, however. A dangerous combustible mixture within a furnace or oven consists of the accumulation of combustibles (gas) mixed with air, in proportions that will result in rapid or uncontrolled combustion (an explosion). It depends on the quantity of gas and the air-to-fuel ratio at the moment of ignition.
Source: Bruce Yates, "Ten Tips for Safeguarding Combustion Processes"
#flamedetection #combustion #valves
4. Remember that Flame Safety Starts with Purging
The sequence for flame safety starts with purging the furnace or oven. Purge time should allow for four air changes.
Fuel valves can — and do — leak gas. The purpose of purging is to remove combustible gases from the combustion chamber before introducing an ignition source. The four air changes in the combustion chamber are based on a worst-case scenario that includes having a burner chamber that is completely filled with gas.
Once airflow for purge is verified, the proof-of-valve closure is confined and safety limits are proven. Then the purge timer — which may or may not be integral to the combustion safeguard — determines the period of time required to evacuate the combustion chamber.
Source: Bruce Yates, "Ten Tips for Safeguarding Combustion Processes"
Let’s discover new tricks and old tips on how to best serve air and atmosphere furnace systems. In this series, Heat Treat Today compiles top tips from experts around the industry for optimal furnace maintenance, inspection, combustion, data recording, testing, and more. Part 1, today's tips, examines seals and leak points.
This Technical Tuesday article is compiled from tips in Heat Treat Today's February Air & Atmosphere Furnace Systems print edition. If you have any tips of your own about air and atmosphere furnaces, our editors would be interested in sharing them online at www.heattreattoday.com. Email Bethany Leone at bethany@heattreattoday.com with your own ideas!
1. Tip-Up Furnace Perimeter Insulation Maintenance Is Key to Efficiency & Quality
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Due to their construction, the insulation at the perimeter of a tip-up furnace is subject to more abuse than typical furnace insulation. Whether from the repeated stress of cycling the case open and closed — or from high temperature operation — fiber modules will eventually begin to shrink/compact. Be watchful for high case temperatures (or worse: case discoloration and paint damage) as a signal that insulation issues are present in that area.
Heat-damaged case wall Source: Premier Furnace Specialists
An air/atmosphere tight seal is critical for maintaining heating efficiency and process quality. Inspect the seal material around the furnace perimeter often and replace sections that are worn. Common perimeter seals are sand seals, fiberglass tadpole tapes, and insulating fiber blankets. These sealing materials are easy to keep on hand to ensure a quality seal is never delayed by lengthy lead times or supply chain issues.
Seals are everywhere on any furnace. Do you know where all the seals and leak points are? Rope gaskets is an obvious example; high temperature gaskets need to be flat, smooth, and unbroken. Another clear example is in the world of vacuum furnaces: O-rings need to be clean and protected from abrasion. Almost every item of your furnace is sealed in some manner. It is best to replace seals as part of a preventative maintenance program. While your nose can detect ammonia, vacuum leaks require special helium leak detectors and a lot of training. Your furnace manufacturer’s service technician can assist in identifying problem areas and developing a maintenance routine to keep your furnace running. And a simple electronic manometer is great to have handy for running leak-down tests using positive pressures. Auto supply stores sell inexpensive halogen detectors, and some people use smoke bombs to detect leaks.
The Korea Institute of Materials Science (KIMS), a government-funded research institute under the Ministry of Science and ICT, has invested in a new vacuum furnace from a manufacturer headquartered in North America.
Nikola Dzepina Nitrex Regional Manager – Asia Source: NITREX
KIMS conducts a wide range of technological R&D activities, including process improvements, application development, material enhancement, testing, and evaluation. The new Nitrex vacuum furnace will support domestic companies -- including Hanwha Aerospace, Doosan Enerbility, Sung-il Turbine, and Samjeong Turbine -- in a development project that aims to improve the cycle efficiency of industrial land-based gas turbines.
The furnace is a horizontal type 2-Bar external quench equipped with a curved molybdenum wide band heating element arranged in a circular configuration around the main hot zone. Its work area measures 15″ in width by 15″ in height by 24″ in length (381 x 381 x 610 mm).
“The Nitrex system can support a wider range of R&D projects and metals,” said Nikola Dzepina, regional manager in Asia at Nitrex. “With the ability to achieve higher vacuum levels with 10-6 Torr ultimate range, the furnace can heat treat parts at temperatures up to 1,371°C (2,500°F).”
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Welcome to Heat TreatToday's This Week in Heat TreatSocial Media. You know and we know: there is too much content available on the web, and it’s next to impossible to sift through all of the articles and posts that flood our inboxes and notifications on a daily basis. So, Heat TreatToday is here to bring you a hot take of the latest compelling, inspiring, and entertaining heat treat chatter from the world of social media.
Today, check out some posts on everything from a new design to an interactive periodic table to ways to shore up your heat treat knowledge. Don't forget to thank an engineer for Engineer Appreciation Week!
Check out a winner from the Metal Powder Industries Federation 2022 PM Design Excellence Awards Competition. This device is used in laparoscopic surgeries! In order to make the curved jaw piece needed for the instrument, the powder metallurgy metal injection molding process was used. Take a look at this piece from all angles with the video below.
2. Continuing Education
Each of these posts brings an educational aspect for you in your heat treat knowledge base. Something new or something to refresh those brain cells, take some learning moments with these posts.
7 Components To Think About with an Industrial Oven Purchase
DFARS Compliance, Free eBook
Preventing Refractory Anchoring System Failures
Advancing 3D Printed Metals with HIP
Interactive Periodic Table 2.0
3. "Molten" Videos
Too hot to handle? We think not. Check out some of these action shots.
4. The Reading (and Podcast) Corner
Time to take your afternoon coffee and read or listen to a few technical pieces from around the industry, or put on an episode of Heat TreatRadio to enjoy as you commute home!
Here's a recent edition from expert Mike Mouilleseaux on underrated heat treat processes.
With a nod to engineering week, this article delves into categorizing things. "Art or Engineering" explores how to think about products, maybe stretching to think differently about labels applied to things.
5. Engineer Appreciation Week
Spreading the love this week for the engineers among us. Thanks for everything that you do!
6. Updating the Office Space!
This office model might be something you want to incorporate? Looks like some great spots to go over the heat treat paperwork and take the calls.
Nordic Traction Group, a manufacturer of traction chains and tracks for forestry and agricultural machinery, recently upgraded their heat treatment operations by installing a new endothermic gas generator system.
Daniel Panny Head of Sales UPC-Marathon in Germany Source: LinkedIn
To carburize its traction chains, Nordic Traction Group, with manufacturing locations in Finland and Scotland, added the EndoFlex™ S system. The system, from UPC-Marathon, a Nitrex company with North American locations, replaces an outdated generator. The new system improves process reliability and product quality and requires less preventative maintenance.
“Since the EndoFlex™ S produces only the amount of gas required by the carburizing furnace, there is zero waste in endogas production. This also allows Nordic Traction to save big by maximizing energy usage and gas consumption,” said DanielPanny, Head of Sales at UPC-Marathon.
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The Lenox Group, an aluminum extrusion profiles company, decided to add a turnkey nitriding system from a supplier with North American locations. The new heat treat furnace will further aid in production of products like windows, doors, solar panels, lighting systems, etc.
Marcin Stokłosa Project Manager Nitrex Poland LinkedIn.com
Lenox has opted to bring operations in-house (in Bulgaria) to improve die reliability through more stringent quality control. “Previously, the company sent extrusion dies for salt bath nitriding and gas nitriding," explains Marcin Stokłosa, project manager at Nitrex. "Lenox Group experimented with various case hardening technologies in search of the best one, the results of which would be repeatable and consistent with their expectations."
The N-EXT 412 is a compact-size Nitrex gas nitriding furnace for low volume quantities. This turnkey nitriding system is built on a self-contained platform that includes the furnace, control system with Nitreg® technology, and an exhaust neutralizer for clean and green processing. With a temperature distribution of +/-5°C, it is suitable for nitriding H11 and H13 extrusion dies.
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All the buzz in our industry seems to indicate that additive manufacturing (AM) and 3D printing are the next hot topics in heat treat, particularly in vacuum heat treat. Heat Treat Today decided to find out how these new technologies are shaping the industry. Read what five heat treat industry leaders had to say about how their companies are preparing for the next generation of AM and 3D printing.
This Technical Tuesday article bringing together the responses from these five companies was first published in Heat Treat Today‘s November 2022 Vacuum print edition.
What changes have you made to accommodate the AM/3D printing marketplace?
Dennis Beauchesne General Manager ECM USA, Inc.
The most important changes relate to the build plate size and how it connects to our standard size systems. Build plates are ever-changing, it seems, as customers have new applications and mostly larger build plates are being requested. In addition, the process parameters – such as temperature and time at temperature and quantity of material – are important. These two items have the most to do with reconfiguring equipment for the AM market. We have also been able to implement our wide range of automation and robotics skills into this equipment as the market scales up for high production.
How will your products and/or services change to accommodate this marketplace?
We are/will be introducing equipment that is in line with standard-build plate dimensions along with reducing operating costs.
Share how 3D printing or AM products/services help heat treaters.
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Recent debind and sinter applications have involved, as previously mentioned, complete robotics to handle parts after printing, to debind, to sinter, and then to process specialized by ECM, such as low-pressure carburizing. ECM has also provided equipment to provide all three processes in the same furnace without moving the load or requiring the furnace to cool and reheat. This reduces work processing time along with less handling and less utility cost.
What changes have you made to accommodate the AM/3D printing marketplace?
Mark Hemsath Vice President of Sales, Americas Nitrex Heat Treating Services
Nitrex Vacuum Furnaces, through its GM Enterprises acquisition, has moved heavily into additive manufacturing via large production MIM furnaces, which are able to both remove large amounts of powder binders and sinter the parts in the same process. We are in the process of installing and/or starting up five furnaces for these markets, and we have recently employed even more advanced concepts on high volume wax removal. A further trend is on higher value materials, like nickel and cobalt alloys and titanium, necessitating diffusion vacuum levels for processing. Nitrex Vacuum has had this experience already for many years, so moving to smaller scale 3D designs comes with years of experience.
How might your products and/or services change to accommodate this marketplace?
Smaller units are a trend to keep an eye on. We have over a decade of learning from the large units we offer, and this will allow us to compete in these lower volume markets (i.e., 3D) via our proven expertise. Several facts/ideas that we are keeping top of mind are:
Large potential in the future (whole new market starting to evolve)
Redesign the product to meet the new needs
Good for rapid prototyping and quick low volume parts
Furnaces need to be available with fast delivery 3D printing is finding a tremendous niche in fast part production, sourced internally or sourced quickly. These parts may cost more per piece, but having them fast is often more important, and 3D offers this ability to cut weeks or months off of supply chain sourcing.
Share how 3D printing or AM products/services help heat treaters.
The AM sector is still in growth mode. How we help is to give a full-service solution to those customers who want to really increase their volume yet use vacuum in the process. Vacuum helps to transport the binder vapors away from the parts and into the traps for removal. Full binder removal adds to the quality of the parts, as does vacuum sintering of the final parts. We have supplied a few systems over the years with higher, diffusion vacuum levels. As powder materials evolve to higher value materials, there is more interest in diffusion vacuum, and we recently supplied such a system.
What do readers need to know about AM/3D to make decisions today?
Vacuum is the proper way to debind and sinter. Additionally, 3D printing started slow and there were many technologies evolving. Now, it has started to really grow, and the need for smaller furnaces that can offer the same quality as MIM parts produced in high volumes will be a need for 3D part makers, in medium to low volume parts. This may involve furnaces for sinter only, debind and sinter, or even sinter and heat treat. We can see the need to both sinter 3D parts in a small furnace and also heat treat them with special added processes and surface treatments.
What changes have you made to accommodate the AM/3D printing marketplace?
Phil Harris Marketing Manager Paulo
Adding a hot isostatic press has been the most notable change Paulo has made to serve the growing AM market. It goes a step further than that though; heat treatment of AM parts has rapidly evolved, and the desire for custom cycles and more data has caused us to make instrumentation changes and do more R&D type work. Understanding the full production path of the parts and doing our part to reduce the time parts are spending in post-processing steps, including offering stress relief, HIP, EDM, and vacuum heat treatment in a one-stop-shop.
How might your products and/or services change to accommodate this marketplace?
As trials continue and boundaries are pushed for both additive and the accompanying thermal processing, we’re constantly keeping an eye on what’s next. Investing in equipment that’s capable while maintaining and instrumenting it to provide the data and reliability the market needs is the name of the game. Of course, open communication with additive manufacturers and printer designers makes this far easier. We value communication with printer manufacturers as it helps us understand demand for our services in terms of build plate size, since, as we all know, furnaces and HIP vessels aren’t one size fits all!
Share how 3D printing or AM products/services help heat treaters.
Additive parts have become commonplace and we’re now regularly providing HIP, stress relief, and solution treating for them. A more interesting example is for parts printed in Inconel 718; we’ve developed a combined HIP and heat treat (or High Pressure Heat Treat) cycle which was able meet material properties specifications when the traditional processing techniques were not. This is where we feel the real cutting edge is when it comes to heat treatment of additive parts; the slow cooling HIP cycles developed for casting decades ago aren’t always optimal for today’s additive parts.
What changes have you made to accommodate the AM/3D printing marketplace?
Trevor Jones President Solar Manufacturing, Inc. Source: Solar Manufacturing, Inc.
There are several methods for 3D printing and we as heat treaters and vacuum furnace manufacturers generally classify those methods into two basic groups: those that use liquid binding polymers and those that do not.
For the group who does not use liquid binding polymers, there are no changes thus far to the design of the vacuum furnace that must be made. One significant caution is insuring there is no loose powder on the surface or cavities of the parts. Residual powder on or in the parts could have adverse effects on the parts themselves and to the vacuum furnace. The loose powder can liberate from the part during the heat treat or quench steps during the process and contaminate the vacuum furnace. The powder in the furnace is then considered FOD (foreign object debris) for subsequent heat treatments processed in that furnace. The powder could also accumulate over time and cause an electrical ground the heating elements or the quench motor, clog the heat exchanger, contaminate vacuum gauges and hot zone insulation, among other issues.
For the group that does contain liquid binding polymers, in addition to the comments about avoiding loose powder on or in the parts, care must also be taken to accommodate for the vaporization of the binder that occurs during heating of the parts. The binder, in its vapor form, will condense at cooler areas in the vacuum furnace. The condensed areas are potential contamination points and could have all the same issues and concerns of loose powder as described above. The binder collection locations, whether at intentional or non-intentional places, will also have to be routinely cleaned to maintain ideal binder collection, optimum vacuum pumping, and overall furnace performance.
How might your products and/or services change to accommodate this marketplace?
With the growth of 3D printing using liquid binder polymers, Solar Manufacturing has taken what was learned from the furnace modified at Solar Atmospheres of Western PA for MIM and AM processing and applied it to a new furnace product line specific for the debind and sinter applications. Solar Manufacturing collaborated with our affiliate company, Solar Atmospheres of Western PA, in modifying an existing vacuum furnace to accommodate the debind and sintering processes. A modified hot zone was installed, and a dedicated binder pumping port was added that helps minimize and target the condensation of detrimental binders evaporating out of parts containing binders. The modified Solar Atmospheres furnace is extremely valuable in gaining knowledge about various aspects of the process and learning what works, and what does not work, in furnace and recipe design. Combining the knowledge and experience of process development of Solar Atmospheres with the advanced Engineering Design Team at Solar Manufacturing, we believe we have a furnace design that modernizes and simplifies the debinding process while minimizing traditional maintenance issues.
Share how 3D printing or AM products/services help heat treaters.
We developed a process of debinding and sintering stainless steel parts with our affiliate company Solar Atmospheres in Souderton PA. The project started out with our Research and Development group to develop the process for the client’s parts. As the trials scaled up, test coupons became test parts, eventually full-size loads. There are always challenges to scaling up from test parts to production loads and we were able to provide the support the customer needed through that transition. The R&D eff orts were successful, and the client ended up purchasing multiple furnaces, which was the end goal for both parties.
Additionally, Solar Atmospheres is currently vacuum stress relieving a 3D component for a major U.S.-based aerospace company that is in use in aircraft today. Also, numerous large-scale components destined for deep space.
What do readers need to know about AM/3D to make decisions today?
Bob Hill, president of Solar Atmospheres of Western PA, reminded us to “realize and acknowledge that AM is still in its infancy stage. Therefore, many metallurgical uncertainties still exist for the multiple printing processes that exist. Understanding this new kind of metallurgy for each printing process, while developing standards and specifications unique to additive manufacturing, is still a huge obstacle. Until this is accomplished, AM will not be the ‘disruptive’ technology that all the experts predict it will be.” If your business is printing parts with liquid polymer binders, you should seriously consider how you plan on debinding and sintering the parts ahead of time. Printed parts in the “Green” or even “Brown” state are fragile and if you are going to ship the parts somewhere else for the debind and sinter steps, extreme care must be taken to prevent the parts from fracturing during transit. Although the shipping can be safely and successfully accomplished, ideally a furnace is available at the print shop to immediately perform the debind and sinter process to avoid those potential shipping difficulties. The other forms of 3D printing that do not contain liquid polymers generally do have this issue.
What changes have you made to accommodate the AM/3D printing marketplace?
Ben Gasbarre Executive Vice President Sales & Marketing Gasbarre Thermal Processing Systems
From our inception, Gasbarre has had expertise in the powder metallurgy industry, which requires debind and sinter applications similar to that in the AM and 3D printing markets. Our ability to supply equipment for both powder and parts producers has set us up for quick adoption into this market. While considerations need to be made specific to AM, our focus has been on technical support and helping the market grow to higher volume applications.
How might your products and/or services change to accommodate this marketplace?
As adoption of these technologies grow, the volume at which parts need to be produced will grow. Our line of continuous processing equipment in both vacuum and atmosphere applications are well suited. Whether it be debind and sinter, annealing, or stress relieving, we have equipment and expertise that can grow from early production to high volumes.
Share how 3D printing or AM products/services help heat treaters.
Overall, Gasbarre is here to be a resource and support the growth of the additive market. Whether that be through new equipment, servicing existing equipment, or involvement in the industry organizations, we have the expertise to drive success today and into the future!
What do readers need to know about AM/3D to make decisions today?
Additive manufacturing is such a dynamic technology, it is difficult to state one specific item. There is the potential for significant growth opportunities for new applications, but also the potential replacement of traditional manufacturing methods. We also know there is substantial backing for the technology by both private industry and government entities. Like other emerging technologies in the automotive and energies sectors, additive manufacturing isn’t a matter of if, but when it’ll achieve wide scale adoption and high-volume applications.
It is amazing how the list of materials being utilized with this technology is growing. While metals and alloys have not been the majority of the market, it is rapidly growing. With that growth, there is a wide variety of applications and thermal processing requirements for those materials. As well, the different additive and 3D printing processing methods (i.e., binder jetting, powder bed fusion, etc.) leads to a similar diversity in thermal processing requirements.
A manufacturer in Poland turns to in-house heat treating capabilities rather than outsourcing its nitriding for stainless steel power generation parts. Steam turbine components will now be processed at the facility in Elbląg as a result of funding help from a government program part of the European Union.
Marcin Stokłosa Project Manager Nitrex Poland LinkedIn.com
P.W.P.T. POSTEOR Sp. z o. omade the decision to stop outsourcing to commercial heat treaters its steam turbine pieces to bring the nitriding in house. The NX series furnace, model NX-620 will streamline production of these parts with its automated capabilities. The pit type furnace from NITREXmeets requirement for nitriding, nitrocarburizing, and in-process oxidation. “The turnkey system also includes remote access software, an INS neutralizer for a clean and environment-friendly process, and a custom HMI for the end-user," describes Marcin Stokłosa, project manager at NITREX. "It is entirely automated, requiring little operator attendance or involvement."
POSTEOR hopes to reduce the challenges it was facing in outsourcing the components. With the nitriding furnace the company will have more positive control of the end results.
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The privilege of unveiling the Heat Treat Today40 Under 40 Class of 2022 comes with the reality that not every one of the nominees could be included in the final count; even though each young, up-and-coming, talented heat treating professional whose name was submitted is making a significant difference in their field.
The individuals pictured are those we acknowledge in 2022 for their contribution to their company, their dedication of service to their customers, and their commitment to pursue skills and knowledge to further contribute to their field.
Caleb Johnson Field Service Manager SECO/VACUUM Technologies LLC
Sergio Luevano Product Manager Nitrex
Sean Rupprecht Mechanical Engineer Gasbarre Thermal Processing Systems
Heat Treat Today will be back next year looking for rising leaders in the 40 Under 40 Class of 2023. We encourage you to consider the talented young professionals in the heat treating sphere, especially in the captive heat treatment industry, who deserve this recognition for their leadership. You can begin the process right now: Click here to nominate a young professional for Summer 2023.
The Capi Group has boosted its nitriding/nitrocarburizing capacity with two heat treat furnaces to keep up with the rise in production and new orders from the industrial and automotive sectors.
Marcin Stokłosa Project Manager Nitrex Poland LinkedIn.com
The Italian gear manufacturer's order of Nitrex's large-capacity nitriding systems "is a continuation of our collaboration, and we look forward to strengthening this partnership further,” says Marcin Stokłosa, project manager at Nitrex.
The Capi Group owns four pit-type nitriding/nitrocarburizing furnaces of the same model type and larger size, which consist of Nitreg® and Nitreg®-C technologies, +/-3°C temperature homogeneity in the retort, and eco-friendly IN-500 exhaust neutralizer to support a clean and green operation.
The new Nitrex furnaces, which comply with the Aerospace Material Specifications (AMS) 2750 for pyrometry and 2759/10 for controlled nitriding, are integrated into the existing production line and connected to a closed-loop water cooling system. The latter is an environmentally friendly feature that recirculates a steady supply of cooling water to cool furnace elements.
The new systems have been operational for a few months.
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