laura

Quench Oil Management: AMS2759 & CQI-9

/ AEROSPACE HEAT TREAT TECHNICAL CONTENT, QUENCHING TECHNICAL CONTENT

Given safety and performance concerns in the aerospace sector, it may be beneficial to consider quench testing that uses CQI-9 as well as AMS2759 since the automotive standard focuses on safety. Read on to understand the different approaches between these two standards in this Technical Tuesday installment, written by Michelle Bennett, quality assurance senior specialist, and Greg Steiger, senior account manager, both at Idemitsu Lubricants America.

This informative piece was first released in Heat Treat Today’s March 2025 Aerospace Heat Treating print edition.

In today’s world, there are many different quality systems available to heat treaters. Many of these, such as ISO, are quality management systems. These quality management systems are an important piece of running a successful business. However, to successfully run a heat treat business and compete in either the North American automotive market or the aerospace market, a heat treater must conform to either CQI-9 or AMS2759, or, in cases where a company processes both automotive and aerospace parts, both. This article will explain the requirements for both CQI-9 and AMS2759. It will also explain the differences between the two quality standards and any additional testing that could benefit a heat treater or how they operate their quench tank.

AIAG’s CQI-9

The Automotive Industry Action Group (AIAG) is a non-profit group of over 800 automotive OEMS, parts manufacturers, and service providers who oversee the requirements for CQI-9. The 4th edition is the most current edition of CQI-9. As an internal audit process, CQI-9 covers most of the heat treating process. Section 3.14 specifies the quench oil and water-soluble polymer requirements. An oil quenchant requires that the in-use oils be tested every six months and the testing must include water content, percent suspended solids, total acid number, viscosity, flash point, and cooling curve. The specification range and warning limits are based on the vendor’s requirements and recommendations. For water-based polymers, there are two tests required: concentration and quenchability. The standard does not specify a test for quenchability, however, it does make a few suggestions such as a cooling curve, viscosity, and titration.

For water-based polymers, there are two tests required: concentration and quenchability. The standard does not specify a test for quenchability, however, it does make a few suggestions such as a cooling curve, viscosity, and titration.

All the required testing of the quenchant is designed to achieve consistent metallurgy for safety reasons. Viscosity is monitored to look for oxidation or heat decomposition of the oil. Degradation can be in the form of oxidation, thermal breakdown, or the presence of various contaminants. Increased oil viscosity typically results in decreased heat transfer rates. A decrease in viscosity may indicate contamination. Some suspended solids are to be expected during the quenching process, but the majority of them should be filtered or centrifuged from the process. If the quantity of these contaminants becomes too high, then it can both affect the brightness of the parts, and the parts can get soft spots as the contaminants may not cool the parts at the same rate.

Water and flash point are both monitored for safety. If the flash point drops below the accepted range or the water content is above the acceptable range, these can cause fires during the operation. Water can also show issues with the equipment or the procedure such as leaking of anything that is water cooled, such as the outer door on a furnace. Acid value is monitored to degradation of the oil. As the oil breaks down and oxidizes, the acid value will increase. This can cause the maximum cooling rate to increase and can cause cracking or distortion on the parts. Carbon residue can be measured for two reasons. If the result is below the specification, it can show that the quench speed improver is being broken down or dragged out of the system. If the result is higher than the specification, it can show the formation of sludge, which will impact the brightness of the parts.

For water-based quenchants, the most common test items include pH, refractive index or brix, viscosity, and concentration calculation. Sometimes additional test items can be added, such as biological testing, to help determine and correct current issues.

Table 1. CQI-9 vs. AMS2759 quenchant requirements

SAE’s AMS2759

Just as AIAG is a non-profit business group responsible for CQI-9, SAE International is a non-profit organization responsible for AMS2759. The most recent revision of AMS2759 is Revision G. AMEC (the Aerospace Materials Engineering Committee) is responsible for maintaining this standard. Unlike CQI-9, AMS2759 requires a certificate of conformance for all shipments. Section 3.10.3 begins the requirements for quenchant testing and quenchant deliveries. Viscosity, flash point, and temperature at the maximum cooling rate must be reported on the certificate of compliance when dealing with mineral oil quenchants. For a polymer, the requirements are that the pH of the neat polymer and the neat viscosity of the polymer must both be reported on the certificate. Also required on the polymer certificate are the viscosity, pH, and the temperature at the maximum cooling rate for polymers at 20% dilution by weight.

Similarly to CQI-9, AMS requires that the in-use quenchants be tested biannually. This standard, however, only requires the cooling rate and temperature at max cooling rate be tested, as well as any additional tests the supplier recommends. The AMS2759 specification does not have set limitations on the cooling rate and temperature. Instead, the specification sets the allowed upper and lower deviations from the supplier’s standard for the maximum cooling rate and the temperature at the maximum cooling rate for both oils and water-soluble polymers. The supplier should have calculated the average max cooling rate and average temperature at max cooling rate using many different blend lots and multiple test runs. This average will not vary or change based on current production values or the values for the batch that the client is currently using (Table 1).

Although both standards require having the quenchant tested bi-yearly, most quenchant suppliers encourage their clients to submit their furnace samples for testing quarterly. This ensures that the medium is being monitored frequently, and if a sample is missed or late when sampling quarterly, then the client is still within compliance for the six month testing requirements.

However, because many of the test parameters in CQI-9 are run for safety reasons along with performance reasons, it is highly advised that aerospace heat treaters should run the full suite of CQI-9 testing along with the AMS2759 testing.

Taking a Quench Sample

There are many different quench methods and both standards allow for any of the following variations: ASTM D6200, ISO 9950, JIS K2242, ASTM D6482, or ASTM D6549. The type of testing that is going to be conducted will determine the size of sample that will be needed. For just this quench testing, the volume of sample needed ranges from 250 milliliters to 2 liters.

As always, when taking samples, it is important to be sure to get a good representative sample of the current quenchant being used in the process. The agitation needs to be running and collected in a clean and dry container. The sampling site should be the most convenient location to safely obtain a sample. It should also be the same location for every sample. The lid also needs to be put on before the oil cools too much because the container will draw in moisture and condensation as the oil cools if it is open to the atmosphere.

Conclusion

When examining the standards, there is one basic commonality: the need to run a complete cooling curve every six months. There is also a large difference in that AMS2759 does not require the full suite of testing that CQI-9 does. However, because many of the test parameters in CQI-9 are run for safety reasons along with performance reasons, it is highly advised that aerospace heat treaters should run the full suite of CQI-9 testing along with the AMS2759 testing. For automotive heat treaters, the maximum cooling rate and the temperature at maximum cooling rate is something that can be reported in the normal D6200 cooling curve test.

For manufacturers heat treating parts for aerospace, automotive, or both markets, we recommend quarterly quench samples at a minimum. The primary reason for more frequent testing is safety. Also, with the current labor shortage, heat treaters are busier than ever. If quench samples are routinely taken on a quarterly basis and are somehow missed and forgotten, there is still time to take another sample and remain in CQI-9 and AMS2759 compliance.

Remaining in compliance of these two important standards requires a lot of hard work from both the heat treater and the quenchant provider. Unless the quenchant supplier is working together in a true partnership, it will be very difficult to remain in compliance with the requirements for CQI-9 and AMS2759. But with routine monitoring, heat treaters can help to ensure quenchant and equipment have a longer life and achieve ever-tightening requirements from clients.

About The Authors:

Michelle Bennett
Quality Assurance Senior Specialist
Idemitsu Lubricants America

Michelle Bennett is the quality assurance senior specialist at Idemitsu Lubricants America, supervising the company’s I-LAS used oil analysis program. Over the past 12 years, she has worked in the quality control lab and the research and development department. Her bachelor’s degree is in Chemistry from Indiana University. Michelle is a recipient of Heat Treat Today’s 40 Under 40 Class of 2023 award.

Greg Steiger
Senior Account Manager
Idemitsu Lubricants America

Greg Steiger is the senior account manager at Idemitsu Lubricants America. Previous to this position, Steiger served in a variety of technical service, research and development, and sales and marketing roles for Chemtool Incorporated, Witco Chemical Company, Inc., D.A. Stuart Company, and Safety-Kleen, Inc. He obtained a BS in Chemistry from the University of Illinois at Chicago and recently earned a master’s degree in Materials Engineering at Auburn University. He is also a member of ASM International.

For more information: Contact Michelle Bennett at mbennett.8224@idemitsu.com or Greg Steiger at gsteiger.9910@idemitsu.com.

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

Quench Oil Management: AMS2759 & CQI-9 Read More »

Heat Treat Economic Indicators: March 2025 Results

/ HEAT TREAT ECONOMIC NEWS, HEAT TREAT NEWS

The four heat treat industry-specific economic indicators have been gathered by Heat Treat Today each month since June 2023. As the northern hemisphere looks to warmer weather, a positive outlook is reflected in three of the four economic indicators compiled in the first week of March.

Heat treat industry suppliers anticipate the economy in March to experience growth in number of inquiries, value of bookings, and size of backlog, however there is a net decrease compared to February. This is particularly shown in the economic indicators where suppliers to the North American heat treat industry expect no change over previous months in health of the manufacturing economy.

The results from this month’s survey (March) are as follows; numbers above 50 indicate growth, numbers below 50 indicate contraction, and the number 50 indicates no change:

  • Anticipated change in Number of Inquiries from February to March: 61.1
  • Anticipated change in Value of Bookings from February to March: 58.8
  • Anticipated change in Size of Backlog from February to March: 59.5
  • Anticipated change in Health of the Manufacturing Economy from February to March: 50.0

Data for March 2025

The four index numbers are reported monthly by Heat Treat Today and made available on the website. 

Heat Treat Today’s Economic Indicators measure and report on four heat treat industry indices. Each month, approximately 800 individuals who classify themselves as suppliers to the North American heat treat industry receive the survey. Above are the results. Data started being collected in June 2023. If you would like to participate in the monthly survey, please click here to subscribe.

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

Heat Treat Economic Indicators: March 2025 Results Read More »

This Week in Heat Treat Social Media

/ HEAT TREAT NEWS

Welcome to Heat Treat Today’s This Week in Heat Treat Social Media. We’re looking at addendum learning, indepth instruction from industry leaders, and how-tos that will tickle your ears. But first in the posts, podcasts, and videos we have rounded up for you, check out what NASA is doing with shape-shifting tires.

As you know, there is so much content available on the web that 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 Treat Today is here to bring you the latest in compelling, inspiring, and entertaining heat treat news from the different social media venues that you’ve just got to see and read! If you have content that everyone has to see, please send the link to editor@heattreattoday.com.

1. Entering the Realm of Shape-Shifting

This space is usually reserved for something rich and technical, so we’re looking at the science of shape-shifting!

Check out this recent post on ThomasNet about NASA’s foray into the world of physical transformations.

2. It’s a Beautiful Day in the Heat Treat Neighborhood

Don’t Skip the Side Trips!

Trades Schools Now Trending

Helping Kids Take Flight

3. A broad Education in Heat Treating Coming Your Way

Sometimes, it’s the small things on social media that grab your attention or give you the “ah ha!” moment. And sometimes things affecting the industry in other places cause us to go “hmm.” Do any of these short posts make you say “eureka”?

How many Terms Do You Already Know?

All About Quenching

Monitoring Leaks and Dew Point Gases

Having a Blast with Furnaces

4. Open Your Eyes & Ears: The Podcast Corner

You can’t read everything, we get it. Heat Treat Today is here to recommend two informative podcasts and one video to enjoy on your daily commute or during your evening roundup.

Tune in to Listen to Heat Treat Radio #118: Saving Dollars with Ceramic Fiber Insulation

Heat Treating Machined Parts To enhance strength, hardness, durability, and flexibility

Carlos Torres Interviews Steve Kowalski on the Heat Treat Podcast

5. Inspections Are Good … Overinspections Can Be Too Good

Have a great weekend!

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

This Week in Heat Treat Social Media Read More »

Why PF and DPF Matter

/ CONTROLS TECHNICAL CONTENT, Manufacturing Heat Treat Technical Content

As heat treating facilities strive for energy efficiency and reliability, investing in power improvements can move a company toward sustainable operations. In this Controls Corner installment, Brian K. Turner of RoMan Manufacturing, Inc. compares real power factor and displacement power factor in the efficiency and electrical performance of vacuum furnaces.

This informative piece was first released in Heat Treat Today’s February 2025 Air/Atmosphere Furnace Systems print edition.

To read the article in Spanish, click here.

In the context of vacuum furnaces, real power factor and displacement power factor are key concepts related to the efficiency and electrical performance of the furnace’s power supply and load. Here’s a comparison:

1. Real Power Factor (PF)

Definition: Real power factor is the ratio of real power (active power, P, measured in watts) to apparent power (S, measured in volt-amperes). It considers both the phase displacement and harmonic distortion.

Relevance to Vacuum Furnaces:

  • Vacuum furnaces, especially those using induction heating, often generate nonlinear loads due to the operation of power electronics.
  • Nonlinear loads introduce harmonics, which distort the current waveform, reducing the real power factor.
  • A low real power factor indicates inefficiency, as the system draws more apparent power for a given amount of real power.

2. Displacement Power Factor (DPF)

Definition: Displacement power factor is the cosine of the angle (ϕ) between the fundamental components of voltage and current waveforms. It ignores harmonic distortion and considers only the phase displacement caused by inductive or capacitive loads.

Relevance to Vacuum Furnaces

  • In vacuum furnaces, the inductive nature of components (e.g., transformers and inductive loads) causes a lagging power factor, which is reflected in the DPF.
  • A poor displacement power factor (e.g., heavily lagging) means the system has significant reactive power demands, affecting the sizing of transformers and power distribution equipment.

The above waveforms illustrate the difference between displacement power factor (DPF) and real power factor (PF) as they relate to current and voltage:

Top Chart: DPF — Ideal Conditions

  • The green sinusoidal waveform represents the current in an ideal displacement power factor scenario, where only phase displacement (ϕ) exists between the voltage (blue curve) and current.
  • The waveforms are clean and sinusoidal, indicating no harmonic distortion.

Bottom Chart: PF — With Harmonic Distortion

  • The red waveform represents the current with added harmonic distortion, typical in systems with nonlinear loads, like vacuum furnaces.
  • This distortion causes the real power factor to drop compared to the displacement power factor, even if the fundamental phase relationship is the same.
Waveforms that illustrate DPF vs. PF as it relates to voltage and current

Effects on Transformer and Utility Transformer Sizing

Increased Apparent Power Demand

  • A lower real power factor (due to harmonics) means the transformer must handle higher apparent power (S), even if the real power (P) is unchanged.
  • This can necessitate larger transformers, increasing capital costs.

Thermal Stress

  • Harmonics lead to additional losses (eddy currents and hysteresis), causing transformers to overheat and reducing their efficiency and lifespan.

Voltage Regulation Issues

  • Harmonics distort the voltage waveform, which can affect sensitive equipment and require transformers with tighter voltage regulation capabilities.

Utility Penalties

  • Utilities often impose penalties for low real power factor, incentivizing users to improve power quality through harmonic filters or power factor correction.

Conclusion

Addressing power factor in vacuum furnaces is crucial for improving efficiency and reducing operational costs. As heat treating facilities strive for energy efficiency and reliability, investing in these improvements is a step toward sustainable operations.

About the Author:

Brian Turner
Sales Applications Engineer
RoMan Manufacturing, Inc.

Brian K. Turner has been with RoMan Manufacturing, Inc., for more than 12 years. Most of that time has been spent managing the R&D Lab. In recent years, he has taken on the role as applications engineer, working with customers and their applications.

For more information: Contact Brian at bturner@romanmfg.com.

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

Why PF and DPF Matter Read More »

MTI Member Profile: Contour Hardening

/ MTI MEMBER PROFILES

If you had to describe Contour Hardening, Inc., in one phrase, it would be: Engineers solving problems. When a client encounters a part failure, this heat treater believes their work has just begun. Founded in 1986 by two engineers (one a metallurgical engineer and one a gear engineer), the company has been solving complex problems with unique, custom designed solutions ever since.

The first problem Contour’s two founding engineers solved was how to handle gears that have such irregular shapes but still need a high degree of case depth and pattern accuracy. What they created is the unique and patented Micropulse™ Process. In the ‘80s, their strategy was to build this advanced, computer-controlled induction heating technology into custom-designed induction hardening machines for OEM manufacturers and tier 1 suppliers. This patented process is a slightly different hardening solution than other available options. Specifically, this process prioritizes keeping the part below the critical temperature zone. Heat times can be controlled to the millisecond, and the time at which the part is above critical temperature can be as low as 0.15 seconds. In addition to this tight temperature control is the ability to use dual frequencies, which provides the custom solution the founding engineers sought after: A heat pattern that precisely contours to the surface of the part.

Zion’s ZSCAN induction scanner outfitted with full-service controls

Equipment — or lack of customized equipment — is another problem to solve on Contour’s list. The company often functions as most commercial heat treaters do, receiving work to process in their on-site equipment. This equipment includes 12 case hardening machines and nitriding and ferritic nitrocarburizing machines. Custom designed equipment, however, also leaves the company’s Indiana or Mexico facilities and is delivered to clients as needed. This is because the company functions with the motto that pre-designed machines are not always best, and sometimes, you just have to build the machine around the part, not the part around the machine. This motto has led Contour to solve many a client’s failure with a unique, built-to-client-speculation machine, delivered on time.

What is Contour’s next set of problems to solve? In the upcoming years, the company is looking forward to providing solutions to bridge the gap between design constraints and manufacturing feasibility. Unmanned drones and electric vehicles are two of the key players in this area. On a broader scale, the company hopes to find a solution that fits the torque requirements of electric motors, as well as keeps the size of components small. Whatever the next problem may be, this group of engineers and heat treaters is prepared to tackle it.

For more information:

Contour Hardening, Inc.

8401 Northwest Boulevard
Indianapolis, IN 46278
United States

nmerrell@contourhardening.com
www.contourhardening.com

Main image: Transmission gear above Curie temperature, contouring the surface

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

MTI Member Profile: Contour Hardening Read More »

El PF y el DPF: ¿importan?

/ CONTROLS TECHNICAL CONTENT, Manufacturing Heat Treat Technical Content

As heat treating facilities strive for energy efficiency and reliability, investing in power improvements can move a company toward sustainable operations. In this Controls Corner installment, Brian K. Turner of RoMan Manufacturing, Inc. compares real power factor and displacement power factor in the efficiency and electrical performance of vacuum furnaces.

This informative piece was first released in Heat Treat Today’s February 2025 Air/Atmosphere Furnace Systems print edition.

To read the article in English, click here.

En el contexto de los hornos de vacío, el factor de potencia real y el factor de potencia de desplazamiento son conceptos claves en relación a la eficiencia y el comportamiento tanto de la fuente de energía eléctrica como de la carga del horno. A continuación, una comparación entre los dos factores.

1. El factor de potencia real (PF, por sus siglas en inglés)

Definición: El factor de potencia real es la relación entre la potencia real (potencia activa, P, medida en vatios) y la potencia aparente (S, medida en voltamperios). Da cuenta tanto del desplazamiento de fase como de la distorsión armónica.

Relevancia para hornos de vacío:

  • Los hornos de vacío, en particular los que funcionan con calentamiento por inducción, con frecuencia generan cargas no lineales debido a la operación de la electrónica de potencia.
  • Las cargas no lineales conllevan armónicos que distorsionan la forma de onda de la corriente generando una disminución en el factor de potencia real.
  • Un bajo factor de potencia real es indicador de ineficiencia ya que el sistema se ve obligado a aumentar el consumo de potencia aparente para generar la potencia real que se requiere.

2. El factor de potencia de desplazamiento (DPF, por sus siglas en inglés)

Definición: El factor de potencia de desplazamiento es el coseno del ángulo (ϕ) entre dos componentes fundamentales: el voltaje y las formas de onda de la corriente.

Relevancia para hornos de vacío

  • En los hornos de vacío la esencia inductiva de los componentes (p.ej., los transformadores y las cargas inductivas) genera un factor de potencia de retardo que se ve reflejado en el DPF.
  • Un bajo factor de potencia de desplazamiento (es decir, con retardo importante) implica demandas significativas para el sistema en cuanto a potencia reactiva, lo que a su vez afecta el tamaño de los transformadores y del equipo de distribución de energía.

Tabla superior: DPF – Condiciones ideales

  • La forma de onda sinusoidal verde representa la corriente en un escenario con factor de desplazamiento de potencia ideal en el que interviene únicamente el desplazamiento de fase (ϕ) entre el voltaje (curva azul) y la corriente.
  • Las formas de onda se ven limpias y sinusoidales, indicando la ausencia de distorsión armónica.

Tabla inferior: PF — Con distorsión armónica

  • La forma de onda roja representa la corriente con la intervención de la distorsión armónica, situación típica de sistemas con cargas no lineales, caso de los hornos de vacío.
  • Esta distorsión genera una disminución en el factor de potencia real frente al factor de potencia de desplazamiento, aún cuando no se haya modificado la relación en la fase fundamental.
Formas de onda que permiten visualizar el DPF vs. el PF en relación a voltaje y corriente

Efecto sobre el tamaño de transformadores y transformadores de distribución

Aumento en la demanda de potencia aparente

  • Un factor de potencia real disminuido (debido a los armónicos) implica que el transformador deberá manejar una mayor potencia aparente (S) sin importar que la potencia real (P) no haya cambiado. Esto puede aumentar los costos de capital al requerir transformadores más grandes.

Estrés térmico

  • Los armónicos llevan a pérdidas adicionales (por las corrientes inducidas y la histéresis) generando el sobrecalentamiento de los transformadores y disminuyendo la eficiencia y duración de los mismos.

Regulación de voltaje

  • Los armónicos distorsionan la forma de onda del voltaje, lo que podría afectar los equipos sensibles y obligar al uso de transformadores capaces de regular de manera más precisa el voltaje.

Penalización por consumo energético

  • Los proveedores del servicio de energía muchas veces aplican sanciones por un bajo factor de potencia real, con lo que buscan incentivar a los usuarios a mejorar la calidad de la potencia mediante el uso de filtros armónicos o corrección del factor de potencia.

Conclusión

La revisión del factor de potencia en los hornos de vacío es de crítica importancia para lograr una mayor eficiencia y la reducción de los costos operativos. En su avance hacia la eficiencia y la fiabilidad energética, invertir en estas mejoras permitirá a las plantas de tratamiento térmico acercarse un paso más a la operatividad sostenible.

Traducido por: Shawna Blair

About the Author:

Brian Turner
Sales Applications Engineer
RoMan Manufacturing, Inc.

Brian K. Turner has been with RoMan Manufacturing, Inc., for more than 12 years. Most of that time has been spent managing the R&D Lab. In recent years, he has taken on the role as applications engineer, working with customers and their applications.

Para contactar a Brian: bturner@romanmfg.com.

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

El PF y el DPF: ¿importan? Read More »

Auto Parts manufacturer Adds EV/CAB Line

/ AUTOMOTIVE HEAT TREAT NEWS, BRAZING NEWS

An auto parts manufacturer that specializes in the production of radiators and air conditioning systems recently ordered a fully electric furnace for brazing aluminum in a protective atmosphere. The EV/CAB line is designed for the production of tubular and plate-fin heat exchangers with uniform temperature distribution across the 1300 mm wide belt.

Piotr Skarbiński
Vice President of Aluminum and CAB Products Segment
SECO/WARWICK

SECO/WARWICK designed the uniform temperature distribution feature in the equipment to meet the company’s quality requirements of the finished products. The CAB line on order, the first this manufacturer has acquired from SECO/WARWICK, provides the continuous brazing of products with similar dimensions and features. The temperature is evenly distributed over the entire width of the belt due to several independent heating zones, resulting in long-term operation under industrial conditions.

“Uniform temperature distribution across the entire belt, regardless of how wide it is, is an important consideration influencing the final effect of the production,” said Piotr Skarbiński, vice president of the Aluminum Process and CAB Business Segment at SECO/WARWICK. “Our furnaces provide an optimal brazing temperature profile and a very clean atmosphere necessary to maintain high process quality. In China, we sell CAB lines for manufacturers of electric vehicle battery coolers, as well as for manufacturers of other heat exchangers. The furnaces on order by this partner are powered by electricity, making them ecological and free of CO2 emissions.”

Press release is available in its original form here.

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

Auto Parts manufacturer Adds EV/CAB Line Read More »

Considerations To Choose Optimum Fixtures

/ FIXTURE RACKING SYSTEMS TECHNICAL CONTENT, Manufacturing Heat Treat Technical Content

Options abound when it comes to selecting the preferred type of fixture. In this Technical Tuesday installment, Garrett Gueldenzoph, applications engineer at Rolled Alloys, examines various advantages of wrought versus cast alloys in heat treat operations.

This informative piece was first released in Heat Treat Today’s February 2025 Air/Atmosphere Furnace Systems print edition.

There are various types of heat treating fixtures, such as trays, racks, boxes, and other part holders available in the market. These fixtures are generally made of castings, wrought fabrications, or hybrids.

For heat treaters, it can be challenging to determine which fixture best suits the job. The decision usually involves a combination of cost and design factors. However, many heat treaters tend to only consider the initial cost and overlook the importance of life cycle costs. It is crucial to consider the cost per pound of heat treated product, which is often overlooked but should be an important consideration.

Cast materials and wrought materials each have their own advantages. The pros and cons of each are summarized in Table 1. Cast materials offer a low cost per unit, the ability to incorporate beneficial elements like Cr and C, higher creep strength, and the ability to be cast into complex shapes that are ready to use.

Wrought alloys can be used in thinner sections, are repairable/weldable, resist thermal fatigue better, and have a better surface finish. Using thinner sections can result in a lower-weight fixture and fewer BTUs to heat the fixture.

Table 1. General comparison of cast vs. wrought materials

Baskets: Wrought and Cast

Baskets are one of the most common heat treating fixtures. A typical basket is shown in Figure 1. This simple basket, made entirely from a wrought round bar, is commonly called a bar basket or rod frame basket. This type of basket is either used as is or lined with wire mesh to hold small parts such as hardware in heat treating facilities. Wire mesh liners are inserted on all five sides to prevent these parts from falling into the furnace. Fully cast baskets or wrought-cast hybrid baskets are also used, but they tend to be heavier due to the larger amount of material they require. These types of baskets are used to support heavier loads than the wrought wire bar basket can handle.

A wrought basket has a lower carbon content and a defined grain structure, making it more resistant to sudden changes in temperature compared to cast baskets or hybrids. This allows it to endure multiple quenching and heating cycles. In contrast, cast baskets may develop cracks from frequent temperature changes. The wrought basket remains resilient to thermal shock until a case is accumulated during case hardening operations.

Cast baskets have a higher carbon content and better resistance to deformation under heavy loads. However, they are more susceptible to cracking than wrought baskets. When choosing between the two, the expected service life and cost per pound for heat treatment are the main economic factors to consider.

Figure 1. Bar basket/rod frame basket

Trays

Trays are commonly used to support heavier parts. There are three main types of trays; two are traditional designs and one is a newer design (see Figure 2). The first traditional tray consists of a serpentine grid made of snakelike bent pieces bordered by consecutive lengths. The pieces are held together by a threaded round bar with nuts welded to each end. A gap is left at one end between the last straight section and the end nut, allowing for free expansion and contraction of the individual pieces. While the serpentine grid can be made from a relatively thin sheet (11 gauge), higher strength can be achieved by increasing the top-to-bottom grid thickness. The second traditional tray is cast with straight legs connecting to round tubes.

The final tray design features a honeycomb pattern by Duraloy, with relatively thick legs. As a result, this heavy duty grid can support heavier weights compared to the traditional cast grid. These grids are becoming more common in heat treat shops due to their ability to handle significant weight. All three tray designs are depicted in Figure 2.

Figure 2. Tray designs for heat treat fixtures

Design

When designing baskets and trays, it is important to decide how thick the supports should be. Thicker supports can hold more weight, but the furnace capacity should also be taken into account to maximize efficiency.

Optimization

Using a tray with thick support members may not always be the best solution, as the furnace has a weight capacity limit. If the furnace can be run at total capacity, the strength of the fixture is well spent. It is best to use a fixture with the highest utilization, which means having the best possible ratio of part weight to total weight. A fixture that is too small will not allow the furnace to be filled to near capacity, while a fixture that is too heavy will limit the number of parts that can be processed.

Damage

Forklifts are a common cause of basket or fixture failure, especially during case hardening operations. The properties of the fixture material must be considered to prevent failure. For example, cast trays are strong but brittle, while wrought material has good impact resistance.

Custom

The final type of fixture is custom designed. One standard fixture is called a daisy wheel because of its grid-like shape. The decision to use a particular fixture depends on its ability to support parts and its expected lifespan. Cast fixtures tend to split in the joint areas, whereas welded wrought fixtures have more ductility and will not break as quickly in the welds. Stiffeners should be avoided unless some means of movement is provided, as they can cause the material to bend, buckle or crack.

Figure 3. Custom fixture

Materials

In the heat treating industry, fixtures and baskets are often made from a versatile alloy called RA330®. This alloy is resistant to oxidation up to 2100°F (1150°C) and has usable creep strength up to 1800°F (980°C). Most steel heat treatment is done below 1750°F (950°C), and many operations are done below 1600°F (870°C). Sigma phase forms in some fixture materials below 1600°F, which makes them brittle at room temperature and prone to failure eve with slight impacts such as forklift hits. But RA330, with 35% nominal nickel, is immune to sigma phase formation, as are nickel alloys with higher nickel content.

RA330 also has good resistance to surface hardening operations like carburizing and nitriding, but carbon and nitrogen can penetrate the protective oxide and diffuse into the base metal over time. Generally, RA330 fixtures last approximately one year in carburizing atmospheres and should last longer in nitriding environments. They may warp from continued use but are resistant to thermal fatigue.

There are other options for wrought materials, but they are often more expensive than RA330. For instance, RA 253 MA® is an alternative with good creep strength and lower cost than RA330. However, due to its lower nickel content, it is subject to sigma phase embrittlement and does not offer much resistance to carburization or nitriding.

If the fixture is used only for neutral hardening in an inert atmosphere or vacuum, then RA 253 MA may be a cost-effective option. On the other hand, RA 602 CA® has performed exceptionally well as a fixturing material for the highest temperature vacuum heat treating operations, up to temperatures just below 2300°F (1260°C). This alloy has one of the highest creep strengths among all potential wrought products.

Despite the other options, RA330 is still the most economical alloy for heat treating fixtures. However, a higher strength alloy may be considered when final heat treat part dimensions are critical and straightness specifications are tight. Other alloys could be considered, but these fixtures would be restricted to that one application.

References

Glasser, Marc. “RA330: Versatile Nickel Based Alloy for Heat Treating.” Industrial Heating, Sept. 2016.

Rolled Alloys. “Cast vs. Wrought.” https://www.rolledalloys.com/resources/cast-vs-wrought/.

Rolled Alloys. “RA 602 CA® Chosen for Heat Treat Baskets for Extreme High Temperature Vacuum Heat Treating.” https://www.rolledalloys.com/wp-content/uploads/2022/07/RA-602-CA-Chosen-for-Heat-Treat-Baskets_nickel-rolled-alloys-metal-supplier.pdf.

About the Author:

Garrett Gueldenzoph
Applications Engineer
Rolled Alloys

Garrett Gueldenzoph specializes in stainless steel and nickel alloy welding at Rolled Alloys. He holds a bachelor’s degree in Mechanical Engineering from the University of Toledo and is actively involved in several respected technical organizations, including the American Welding Society (AWS), the American Society for Metals (ASM), and the American Society for Testing and Materials (ASTM). Garrett has a strong passion for aerospace and space-related applications, and he plays a key role in enhancing the company’s technical expertise in this market.

For more information: Contact Garrett at ggueldenzoph@rolledalloys.com.

This article was initially published in Industrial Heating. All content here presented is original from the author.

Find heat treating products and services when you search on Heat Treat Buyers Guide.Com

Considerations To Choose Optimum Fixtures Read More »

News From Abroad: Initiatives, Processing for a Better World

/ AUTOMOTIVE HEAT TREAT NEWS, HEAT TREAT NEWS, MANUFACTURING HEAT TREAT NEWS, QUENCHING NEWS

In today’s News from Abroad installment, we highlight processing and initiatives that aim to improve operations and improve sustainability. Read more about a method used in the production of parts with complex geometries; a venture to create the world’s first fossil-free, ore-based steel with renewable electricity and green hydrogen; and a production plant that will generate around 9,000 tons of green hydrogen a year to be used for the production of carbon-reduced steel.

Heat Treat Today partners with two international publications to deliver the latest news, tech tips, and cutting-edge articles that will serve our audience – manufacturers with in-house heat treat. Furnaces International, a Quartz Business Media publication, primarily serves the English-speaking globe, and heat-processing, a Vulkan-Verlag GmbH publication, serves mostly the European and Asian heat treat markets.

Press Hardening Prevents Part Deformation

Press hardening neccessary due to part deformation during the rapid cooling phase induced by quenching
Source: Thermi-Lyon

“Press hardening serves a very specific purpose: to prevent part deformation during the rapid cooling phase induced by quenching. This process improves the performance of steels by giving them a martensitic structure without the need for reworking. Designed for high volume production of parts with complex geometries, press hardening is both highly effective and economical….

This process was initially developed for automotive manufacturers, to process large series of parts with complex geometries. In fact, this method is perfectly suited to the processing of large numbers of parts on a production line: since the cooling cycle is automatically programmed, it can be repeated ad infinitum. What’s more, the circulation of quenching fluid around the part held in the press results in uniform, controlled cooling that can easily be reproduced many times over.”

READ MORE: “Focus on Press Hardening and Its Advantages“ at heat-processing.com. 

HYBRIT Platforms Shift to Fossil-Free Steel

An electricity-based process gas heater for the hydrogen-based direct reduction process developed by HYBRIT (Hydrogen Breakthrough Ironmaking Technology)
Source: Kanthal

“Launched in 2016 as a joint venture owned by SSAB, LKAB, and Vattenfall, with support from the Swedish Energy Agency, HYBRIT aims to create the world’s first fossil-free, ore-based steel with renewable electricity and green hydrogen.

This involves shifting from coal-powered blast furnaces that use coal as a reduction medium to a direct reduction process using hydrogen produced via renewable energy. The first HYBRIT pilot plant in Luleå, Sweden, began operations in 2020, with commercial-scale production targeted by 2027.

Kanthal is proud to have contributed to HYBRIT’s groundbreaking journey by developing an electricity-based process gas heater for the hydrogen-based direct reduction process under the name Prothal®. This project showcased the feasibility of fossil-free industrial heating solutions and laid the groundwork for scaling up these technologies to meet the steel industry’s future needs.”

READ MORE: “Innovations by Kanthal Drive the HYBRIT Revolution for Fossil-Free Steel” at heat-processing.com

Largest Green Hydrogen Production Facility Underway

From left: Andrea Prevedello, Global Director Project Management of Green Hydrogen, at ANDRITZ; Walther Hartl, Project Manager of Electrolysis, at ANDRITZ; Sami Pelkonen, Executive Vice President of Green Hydrogen, at ANDRITZ; Gerd Baresch, Managing Director of the Technical Division, SZFG; Thorsten Hinrichs, Head of Pipeline Infrastructure, SZFG
Source: Andritz Group

“On February 12, 2025, the cornerstone was laid for one of the largest production plants for green hydrogen in the whole of Europe.

[Beginning in] 2026, the plant will generate around 9,000 tons of green hydrogen a year to be used for the production of carbon-reduced steel. This will mark the start of the industrial use of hydrogen in SALCOS®-Salzgitter low CO2 steelmaking. SALCOS® is aiming for virtually carbon-free steel production. The 100 MW electrolysis plant will be supplied on an EPC basis by the international technology company ANDRITZ, using the pressurized alkaline electrolysis technology of HydrogenPro.”

READ MORE: “SALCOS®: Cornerstone Laid for the Production of Green Hydrogen” at heat-processing.com

Find Heat Treating Products And Services When You Search On Heat Treat Buyers Guide.Com

News From Abroad: Initiatives, Processing for a Better World Read More »

Adapting Old Technology for the Future

/ EDITOR

Heat Treat Today publishes twelve print magazines a year and included in each is a letter from the editor, Bethany Leone. In this installment, which first appeared in the February 2025 Air & Atmosphere Heat Treating print edition, Bethany looks at preservation planning on a brownfield through the eyes of a historian and asks the question, “Is it possible an old system can, with modifications, give heat treat operations added value that a newer system cannot?

Feel free to contact Bethany at bethany@heattreattoday.com if you have a question or comment. 

Some readers may know my background is in historical research. In 2022, I found myself supporting a Pittsburgh architect as his team worked on preservation planning on a brownfield: The Carrie Blast Furnaces. Was Carrie a girlfriend? That’s one answer. I never got a good story on that, though.

Among existent structures at the site are the power house, the no. 6 cast house, a dust catcher, a blowing engine house, and two remaining blast furnaces, no. 6 and no. 7. Rusted, massive, and with evidence of guerrilla art everywhere, the “abandoned” site was never really forgotten by the locals who fought to preserve its legacy in the region.

View of the ore yard in front of blast furnaces no. 6 and no. 7 with a red ore bridge overtop

The Carrie Blast Furnaces site is located in the midst of what was a key iron producing region with plants all around the city of Pittsburgh, Western Pennsylvania, parts of West Virginia, and Eastern Ohio. The Pittsburgh district was the largest iron and steel producing region in the world between the late nineteenth and early twentieth centuries.

This industrial site supported U.S. pre-World War II integrated iron production along the Monongahela River. Andrew Carnegie integrated the Homestead Steel Works operations in 1898, the extensive industry marked by tangled railways to transport materials to plants across the landscape.

Various acquisitions and expansions to the space had made it a critical workhorse in America’s manufacturing, eventually becoming a part of U.S. Steel’s Homestead Works. Yet after the world wars, the demand for steel plummeted. Steel manufacturing was consolidated at other locations. Foreign imports increased. Alternative materials were adopted for domestic products. Blast furnaces no. 6 and no. 7, built in 1906–1907, ceased operations in 1978; the rest of the site closed in 1984.

View of six stoves with blast furnace no. 7 (left) and blast furnace no. 6 (right)

Today, Rivers of Steel operates the brownfield. Straddling both Swissvale and Rankin communities, the site has gone under preservation efforts so it can offer the public historic site tours, arts events, hands on education, and outdoor events. But while the technologies can no longer be used on the site, the remaining structures may still yield value to the community.

From an historic preservation perspective, architectural redesign plans intend to keep as many of the structures as is safe and functional for current and future use. Some of the obvious challenges that exist in brownfields are visible to the naked eye: How to insulate or redesign a blowing engine house building and what suppliers are able to fix and replace the broken windows? Can the dust blower have an alternative purpose or is it a hazard to keep on a site that hosts public events? These are relatively simple issues as compared to the subterranean challenges — toxins leaking from latent pipes is the big one. Paired with environmental preservation efforts of redeeming the landscape for safe public use and recreation, making an industrial brownfield something suitable for long-term public benefit requires a host of planning — and unplanning.

Yet the past investments infused into building Carrie Blast Furnaces give value to the future projects, tangible, and intangible.

The stock house where raw materials would be dropped off before carted up to the top of the blast furnaces

The conversation about abandoning older air/atmosphere furnace systems reminds me of this lesson. Is it possible an old system can, with modifications, give heat treat operations added value that a newer system cannot? What with improved furnace insulation, and especially with even advancing furnace monitoring and even technology that leverages carbon emissions within an operation, perhaps certain heat treat operations can create something better and more efficient, leveraging existing investments.

As is the case in historic preservation, an investment can’t always be salvaged or even remembered. We don’t just think about past values or present concerns but future value. I would think the same must be the case for heat treat operations. In navigating the demands of the present economic realities and standards, preparations for the future, while honoring the legacy of workers (and, perhaps, investments) that made it possible is tricky.

Currently, activity at Carrie Blast Furnaces is focused on rebuilding sluiceways for visitors and converting the blowing engine house into a visitor’s center. Hopefully, debate will continue about the rehabilitation investments to come. When it comes to heat treat operations, may we also have great debate in wrestling with old, not so-sexy technologies and whether to adapt or adopt new ones.

Bethany Leone
Managing Editor
Heat Treat Today

Contact Bethany at bethany@heattreattoday.com.

Find Heat Treating Products And Services When You Search On Heat Treat Buyers Guide.Com

 

Adapting Old Technology for the Future Read More »

Skip to content