A batch sintering furnace will be installed at Mueller Brass Co., a major supplier of brass rod and forgings in the United States. The 60" wide x 90" deep x 30" tall atmosphere box sintering furnace includes an accelerated gas cooling system to improve floor-to-floor cycle time and meet their demanding production needs.
This Gasbarre Thermal Processing Systems box furnace is designed with a maximum operating temperature of 1650°F, a capacity of 14,000 lbs., and utilizes a nitrogen atmosphere. The system incorporates an Allen-Bradley PLC with SSi 9130 control and 12.1" HMI display. Additionally, the indirect fired gas heating system incorporates parallel positioning control for efficiency and process flexibility, and an integrated oxygen analyzer gives Muller Brass Co. the proper furnace environment prior to heating.
Tall atmosphere box sintering from Gasbarre Thermal Processing Systems Photo Credit: Gasbarre Thermal Processing Systems
Navigate this summer's heat treat events with Heat TreatToday's Industry Calendar. This hidden gem is located under "Resources" on www.heattreattoday.com, and it is always updating with the latest industry events. As you make your vacation plans, be sure you aren't missing any key events; this June 15th, there are three events going on. Check out these event descriptions in today's original content piece below!
If you have an event to add -- or want to give us a heads up on an event that you and others are going to attend -- feel free to reach out to the editors at editor@heattreattoday.com.
Jump over to the "Resource" tab on www.heattreattoday.com, and you'll find the Industry Calendar located fourth down. This calendar let's you search by month in list or calendar view format so that you can visualize your summer (or fall, or winter, or spring) with ease.
A couple tips to navigate the calendar:
Click "Show Events in Search" to select your desired month (see Image 1).
If you want to learn more about an item in the calendar, hover over the name of the event to see the image (see Image 2).
Want to see the full details of the event? Click the event items, and you'll be redirected to the event page.
Image 1
Image 2
Preview of Summer 2022 Events: June 15, 2022
PowderMet 2022
When: June 12 - June 15
Image 3
"The leading North American technical conference on powder metallurgy and particulate materials, PowderMet2022 is a hub for technology transfer for professionals from every part of the industry, including buyers and specifiers of metal powders, tooling and compacting presses, sintering furnaces, furnace belts. . ."
Process Heating & Cooling Show 2022
When: June 15 - June 16
The inaugural Process Heating & Cooling Show is a place for anyone involved with industrial heating and cooling processes [. . .]. This event will bring together numerous industries in the process industries including oil & gas, electronics, pharmaceuticals, food, beverages, packaging and plastics, to name a few. Plan to join us and connect face-to-face with like-minded peers, learn from business thought leaders, and uncover emerging trends and technologies."
Additive Manufacturing with Powder Metallurgy (AMPM) 2022
When: June 12 - June 15
"Focusing on metal additive manufacturing, AMPM2022 will feature worldwide industry experts presenting the latest technology developments in this fast-growing field."
There's so much more! Explore theIndustry Calendarhere.
What's most important when heat treating: time, quality, costs, aesthetics?
With competing demands, you need to discern when cleaning parts pre- or post-heat treat is a beneficial, or even necessary, step. In today's Technical Tuesday, provided by SAFECHEM, dive into this topic -- to clean or not to clean -- and examine 6 easy questions you can ask yourself when planning any heat treat load.
Is Cleaning a Must in Heat Treat?
The answer is neither a simple "yes" nor a simple "no" – it depends.
In the past, cleaning has not been given much attention to in heat treatment, and the step is often bypassed. However, the attitude is slowly changing. On the one hand, product specifications and higher quality requirements are driving the demand for cleaner products – both visually and qualitatively. On the other hand, evolving materials used in upstream manufacturing has amplified the need for cleaning. Environment-friendly cutting fluids, for example, can go deep into the substrate where their complete removal is necessary to ensure successful thermal treatment.
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But still, the question remains: should you clean or not clean?
To answer that, we need to differentiate between cleaning pre-heat treat, and cleaning post-heat treat.
The main goal of cleaning pre-heat treat is to remove upstream contaminants such as cutting oils, coolants, chips and dust to ensure a clean, smooth surface. Their remnants could otherwise become baked on surfaces which might require costly processes to remove. Pre-cleaning is also key to protecting the furnaces. It prevents the formation of smoke and oil vapors resulting from burned oils, which in itself is also an environmental and worker safety issue.
Pre-Heat Treat Cleaning Key To Nitriding and Carburizing
The reality is that the majority of heat treaters have not fully recognized the need for cleaning prior to heat treat (with the exception of brazing). And this is of particular concern for demanding applications such as nitriding and carburizing, where a cleaned surface is fundamental to achieving good heat treat results.
"Cleanliness conveys quality, standard and care, while also offering protection to critical furnace equipment. For certain heat treat applications, including gas nitriding, ferritic nitrocarburizing and low pressure carburizing, cleaning is almost non-negotiable. For others, cleaning could be a competitive advantage that helps differentiate your products." Photo Credit: Adobe Stock
Insufficient cleaning can lead to challenges such as non-uniform layers, soft spots and stop-off paint issues. Particularly with nitriding, spotty nitriding layers may not be obvious to the eyes and can only be detected under microscope. Phosphate additives in corrosion inhibitors can also work themselves deep into the surface of deep drawn parts, which can cause spotty nitriding patterns if not removed properly.
When it comes to cleaning post-heat treat, cleaning is a standard step after oil quenching where most heat treaters rely on water-based systems to do the job. Of course, it is common knowledge that water and oil do not mix well, so residues could still remain. Therefore, how clean the parts need to be will depend very much on the end-use application (e.g., will the parts be shipped to clients? Will they be machined further?) as well as client quality requirements. Medical applications, for example, would have strict residual particle size limitations in place.
The Real (Hidden) Risk of Not Cleaning
Tackling a heat treat failure where cleaning is an apparent contributing factor needs not be problematic. The real challenge lies in cases where the heat treat process seems to have worked – while in fact it has not.
Complaints about unexpected nitriding/carburizing layers, or component problems with equipment, can arise when parts are in the final assembly, are already in use, or are even out there for many years. The link between these issues and (the lack of/insufficient) cleaning can become very hard to detect by then.
Hence, the pain point for heat treaters does not have to be “in the present.” Client claims issues that come back to bite in the future represent a far greater risk, precisely because of their unpredictability. Cleaning should not be taken lightly because it can mitigate future problems that heat treaters are not necessarily aware of at this point.
The Bottom Line Is This . . .
Cleaning is good housekeeping. Cleanliness conveys quality, standard and care, while also offering protection to critical furnace equipment. For certain heat treat applications, including gas nitriding, ferritic nitrocarburizing and low pressure carburizing, cleaning is almost non-negotiable. For others, cleaning could be a competitive advantage that helps differentiate your products.
When assessing your need to clean, consider these questions:
What would be the cost of not cleaning? I.e., what damage could potential claims cause in terms of money, time, delays, client trust and corporate reputation?
What are the costs to maintain/replace your furnace?
What are the technical justifications?
What are your client expectations in terms of quality, aesthetics, and applications?
What are your corporate standards in terms of health, safety and the environment (HSE)?
Are you producing parts for high-value manufacturing sectors such as aviation, automotive, or medical devices, where your product quality can make or break your business?
Needless to say, cost will be a key driving factor. Do you have a high enough utilization rate to justify the cost of investing in a cleaning system? If not, outsourcing to job shops could be a potential option.
If you do have the cost argument to invest in an in-house solution, do not cut corners! Don’t be tempted to choose the cheapest cleaning option available. Companies do that and realize years later that the system is not working properly and have to shell out another large sum to upgrade their equipment. Because it is not always obvious that your heat treat failures are a direct result of poor cleaning, as a best risk mitigation policy, take a step above rather than a step below – no one loves paying twice!
In the age of new technology, KarenGantzer, managing editor of Heat Treat Today, reflects on a year of "pivoting" to make heat treating content deliverable over the best media. If you don't know about the ebook library and podcast videos on the website, find out what Karen has to say about launching these helpful products.
This article first appeared inHeat Treat Today's December 2021 Vacuum Furnacesprint edition. Feel free to contact Karen Gantzer at karen@heattreattoday.com if you have a question, comment, or any editorial contribution you’d like to submit.
Karen Gantzer Managing Editor Heat TreatToday
Several years ago, I remember hearing glowing reviews about the Barnes and Noble Nook. How wonderful it was to take one device that could hold numerous full-length books instead of actually having to physically carry all of them! Wow, little did we know then how the advent of the Nook, and eventually the Kindle, would not only revolutionize reading for pleasure, but also the way in which we learn and take in information.
As you know, Heat Treat Today believes that people are happier and make better decisions when they are well informed. That often includes pivoting to ensure we are covering all bases to get the information out there. It was with that belief that Heat Treat Today jumped into the ebook realm. There is always excellent technical information to share that will be helpful to you, and ebooks provide a beneficial and user-friendly platform. It’s a win-win for both the authors and readers. And an added bonus is that you don’t even need an e-reader or app to read any of our ebooks. Just download the book on your device and you’re set to go.
There are two titles currently in the Heat Treat Today ebook series. The first one is Hydrogen Generation and Its Benefits for Heat Treaters. It shares useful information about generating your own hydrogen, a key reducing agent in thermal processing atmospheres. Presently, it has almost 350 downloads. The second, High Pressure Heat Treatment: Leading the Renaissance of Hot Isostatic Pressing, explores high pressure heat treating through the many facets and advances of hot isostatic pressing and has 225 downloads. Both were written in cooperation with Nel Hydrogen and Quintus Technologies, respectively.
Keep an eye out for new titles because coming soon to your virtual ebook shelf are books covering AMS2750F and CQI-9 Rev.4. Both are based on the highly popular Heat Treat Radio episodes that discuss these relevant and important standards.
Not only do we have options for the readers, but we also have compelling and informative video formats for those who like to watch and listen. Heat Treat Radio has recently produced special video episodes. One, with close to 300 interactions, is Heat Treat Tomorrow: Experts Look Forward 10 Yearsthat Heat Treat Today partnered with Eurotherm to produce. It includes a panel of 5 experts who address questions about the next 5–10 years in the heat treat industry, specifically focusing on the trends.The latest video, with 71 downloads, is Heat Treat Tomorrow – Hydrogen Combustion: Our Future or Hot Air? In it, Doug Glenn talks with 5 industry experts who address questions about the growing popularity of hydrogen combustion and what heat treaters need to do to prepare. In fact, you can read part of the transcript on page 34.
Heat Treat Todayis here to help you in whatever way we can. So, if you’re interested in collaborating on an ebook or video or have a topic suggestion that is a must for everyone to hear about, please contact me at karen@heattreattoday.com.
In order to meet increasing market demand, a global auto manufacturer is including the installation of a second automated nitriding cell to help expand production capacity of automotive parts. The capital equipment will allow the client to bring the production process in-house for greater control, flexibility, and enhanced effectiveness.
This is the client's third order from Nitrex and second nitriding cell installation in this phase. Nitrex will undertake almost all aspects of the cell for 24/7 lights-out manufacturing: furnaces, charge cars, loading/unloading and magazine tables, and auxiliary equipment (e.g., atmosphere neutralizer, water cooling stations, charge cooling station, etc.). All equipment will be connected to the Protherm 9800 automation platform for automatic handling and processing, which improves workflow efficiency, process reliability, furnace utilization, work order tracking, and real-time performance metrics.For this latest order, six continuous flow-through nitriding systems, furnace model NXHL-910512, were ordered to create the fully automated cell, which is responsible for automatic loading/unloading, processing, and transport. Delivery is planned for August 2022, and the cell should start operating in autumn.
"This chain of events helps increase the plant’s efficiency and productivity: the cell selects the furnaces in which it is possible to place consecutive batches or delivers the batches to several furnaces to process. Since charges are transferred to a cooling station outside the furnace, the furnace can continuously process batches without affecting the workflow and productivity," adds Nikola Dzepina, the executive of International Accounts. "This is a huge process simplification for the furnace operator and enables an automatic and autonomous operation of the area of the plant that controls surface treatment, allowing to increase productivity but also to maintain the repeatability of results."
L&L Special Furnace Co., Inc. model GS1714 Photo Credit: L&L Special Furnace Co., Inc.
A worldwide manufacturer of catalytic convertors, medical devices and pollution environment controls is set to receive 10 bench-top lab furnaces that will be used as part of a precious metals recovery system. The assay division recycles many parts that were originally deployed as catalytic convertors for diesel motors, medical components, and electrical parts.
The precious metals are burned out of the existing product and placed in crucibles. The crucibles are heated in the L&L Special Furnace Co., Inc. model GS1714 at temperatures between 1,800°F/982°C and 2,200°F/1,204°C. This allows any impurities in the metals to rise to the surface and be removed for further refinement. The model GS1714 has an effective work zone of 10” high by 15″ across by 13″ deep.
VIVA ALUMINIUM SYSTEMS – a Vias Group member – has recently acquired a turnkey system for nitriding extrusion dies after experiencing heightened demands for its extrusion profiles.
Marcin Stokłosa Project Manager Nitrex Poland Photo Credit: LinkedIn.com
With these demands from the industrial and construction markets, VIVA decided to expand its manufacturing capacity, installing an additional extrusion press and nitriding equipment. The new pit furnace has an effective work zone of 39" diameter by 59" high (1000 x 1500 mm) with the capacity to nitride a 4400 lbs. (2000 kg) load. The Nitreg® process technology adapts to the application requirements, achieving a high throughput per extrusion run and scoring a high number of runs per treated die, which in turn optimizes tool life and lowers tooling cost for a faster return on investment.
"We are delighted to do business with VIVA again," states Marcin Stoklosa, product manager at Nitrex. "Fostering customer loyalty is a top priority at Nitrex and key to building an ongoing partnership for future growth."
We’ve assembled some of the top 101Heat TreatTips that heat treating professionals submitted over the last three years into today’s original content. If you want more, search for “101 heat treat tips” on the website! Today’s tips will remind you of the importance of materials science and chemistry.
By the way, Heat TreatToday introduced Heat Treat Resources last 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!
Induction Hardening Cast Iron
Induction hardening of cast irons has many similarities with hardening of steels; at the same time, there are specific features that should be addressed. Unlike steels, different types of cast irons may have similar chemical composition but substantially different response to induction hardening. In steels, the carbon content is fixed by chemistry and, upon austenitization, cannot exceed this fixed value. In contrast, in cast irons, there is a “reserve” of carbon in the primary (eutectic) graphite particles. The presence of those graphite particles and the ability of carbon to diffuse into the matrix at temperatures of austenite phase can potentially cause the process variability, because it may produce a localized deviation in an amount of carbon dissolved in the austenitic matrix. This could affect the obtained hardness level and pattern upon quenching. Thus, among other factors, the success in induction hardening of cast irons and its repeatability is greatly affected by a potential variation of matrix carbon content in terms of prior microstructure. If, for some reason, cast iron does not respond to induction hardening in an expected way, then one of the first steps in determining the root cause for such behavior is to make sure that the cast iron has not only the proper chemical composition but matrix as well.
(Dr. Valery Rudnev, FASM, Fellow IFHTSE, Professor Induction, Director Science & Technology, Inductoheat Inc.)
14 Quench Oil Selection Tips
Here are a few of the important factors to consider when selecting a quench oil.
Part Material – chemistry & hardenability
Part loading – fixturing, girds, baskets, part spacing, etc.
Part geometry and mass – thin parts, thick parts, large changes in section size
Distortion characteristics of the part (as a function of loading)
Stress state from prior (manufacturing) operations
Oil type – characteristics, cooling curve data
Oil speed – fast, medium, slow, or marquench
Oil temperature and maximum rate of rise
Agitation – agitators (fixed or variable speed) or pumps
Effective quench tank volume
Quench tank design factors, including number of agitators or pumps, location of agitators, size of agitators, propellor size (diameter, clearance in draft tube), internal tank baffling (draft tubes, directional flow vanes, etc.), flow direction, quench elevator design (flow restrictions), volume of oil, type of agitator (fixed v. 2 speed v. variable speed), maximum (design) temperature rise, and heat exchanger type, size, heat removal rate in BTU/hr & instantaneous BTU/minute.
Height of oil over the load
Required flow velocity through the workload
Post heat treat operations (if any)
(Dan Herring, “The Heat Treat Doctor®”, of The HERRING GROUP, Inc.)
How to Achieve a Good Braze
In vacuum brazing, be certain the faying surfaces are clean, close and parallel. This ensures the capillary action needed for a good braze.
A good brazing filler metal should:
Be able to wet and make a strong bond on the base metal on which it’s to be applied.
Have suitable melt and flow capabilities to permit the necessary capillary action.
Have a well-blended stable chemistry, with minimal separation in the liquid state.
Produce a good braze joint to meet the strength and corrosion requirements.
Depending on the requirements, be able to produce or avoid base metal filler metal interactions.
(ECM USA)
Pay Attention to Material Chemistry
When trying to determine a materials response to heat treatment, it is important to understand its form (e.g., bar, plate, wire, forging, etc.), prior treatments (e.g. mill anneal, mill normalize), chemical composition, grain size, hardenability, and perhaps even the mechanical properties of the heat of steel from which production parts will be manufactured. The material certification sheet supplies this basic information, and it is important to know what these documents are and how to interpret them.
Certain alloying elements have a strong influence on both the response to heat treatment and the ability of the product to perform its intended function. For example, boron in a composition range of 0.0005% to 0.003% is a common addition to fastener steels. It is extremely effective as a hardening agent and impacts hardenability. It does not adversely affect the formability or machinability. Boron permits the use of lower carbon content steels with improved formability and machinability.
During the steelmaking process, failure to tie up the free nitrogen results in the formation of boron nitrides that will prevent the boron from being available for hardening. Titanium and/or aluminum are added for this purpose. It is important, therefore, that the mill carefully controls the titanium/nitrogen ratio. Both titanium and aluminum tend to reduce machinability of the steel, however, the formability typically improves. Boron content in excess of 0.003% has a detrimental effect on impact strength due to grain boundary precipitation.
Since the material certification sheets are based on the entire heat of steel, it is always useful to have an outside laboratory do a full material chemistry (including trace elements) on your incoming raw material. For example, certain trace elements (e.g. titanium, niobium, and aluminum) may retard carburization. In addition, mount and look at the microstructure of the incoming raw material as an indicator of potential heat treat problems.
(Dan Herring, The Heat Treat Doctor®)
Aqueous Quenchant Selection Tips
Determine your quench: Induction or Immersion? Different aqueous quenchants will provide either faster or slower cooling depending upon induction or immersion quenching applications. It is important to select the proper quenchant to meet required metallurgical properties for the application.
Part material: Chemistry and hardenability are important for the critical cooling rate for the application.
Part material: Minimum and maximum section thickness is required to select the proper aqueous quenchant and concentration.
Select the correct aqueous quenchant for the application as there are different chemistries. Choosing the correct aqueous quenchant will provide the required metallurgical properties.
Review selected aqueous quenchant for physical characteristics and cooling curve data at respective concentrations.
Filtration is important for aqueous quenchants to keep the solution as clean as possible.
Check concentration of aqueous quenchant via kinematic viscosity, refractometer, or Greenlight Unit. Concentration should be monitored on a regular basis to ensure the quenchant’s heat extraction capabilities.
Check for contamination (hydraulic oil, etc.) which can have an adverse effect on the products cooling curves and possibly affect metallurgical properties.
Check pH to ensure proper corrosion protection on parts and equipment.
Check microbiologicals which can foul the aqueous quenchant causing unpleasant odors in the quench tank and working environment. If necessary utilize a biostable aqueous quenchant.
Implement a proactive maintenance program from your supplier.
(Quaker Houghton)
Container Clarity Counts!
Assure that container label wording (specifically for identifying chemical contents) matches the corresponding safety data sheets (SDS). Obvious? I have seen situations where the label wording was legible and accurate and there was a matching safety data sheet for the contents, but there was still a problem. The SDS could not be readily located, as it was filed under a chemical synonym, or it was filed under a chemical name, whereas the container displayed a brand name. A few companies label each container with (for instance) a bold number that is set within a large, colored dot. The number refers to the exact corresponding SDS.
(Rick Kaletsky)
Check out these magazines to see where these tips were first featured:
When "the die is cast," heat treaters should make sure that they're using NADCA 207 standards. Prepared by the North American Die Casting Association (NADCA) for its members, they provide recommendations on how to produce dies for die casting to optimize thermal tool life in terms of thermal fatigue.
In today's best of the web article, check out what some of the essential requirements are and how this standard could help in "maximizing the resistance of tools to the occurrence of cracks from thermal fatigue."
An excerpt:
However, the content of this specification is so well processed that it is valid not only for the production of die casting dies and for thermal fatigue, but also for many other applications, and is the best information material for commercial vacuum heat treatment plants, tool shops and die casting foundries, enabling the elimination of fundamental errors in the tool making process.
Heat treaters in the medical and aerospace sectors will eagerly tell you about titanium alloys. The hot alloy can be fantastic for intense applications once you reduce residual stresses that are developed during fabrication and increase their strength. This article is specifically about how duplex heat treatment of Ti alloys helps in relieving stress, optimizing ductility and machinability properties, and increasing strength.
An excerpt:
“Most commonly known for their excellent strength, corrosion resistance and low density, titanium alloys are a key material for important applications in the aerospace and medical industries. Duplex heat treatments of Ti alloys helps in stress relieving, optimizing ductility and machinability properties and increases strength further.”
