One Minute Mentor: Salt Bath Furnaces

The salt bath method of hardening is predominant with high-speed steel tools. With correct operating conditions, tools can be heat treated without carburization, decarburization, and scaling. The surface will be fully hard with a minimum of distortion. The four types of salt baths generally used are preheating baths, high-temperature baths, quenching baths, and tempering baths.

Molten salts of various compositions are well adapted to all operations in the heat treatment of tool steels. For tools that cannot be ground after hardening or for tools that require an excellent surface condition and the maintenance of sharp edges, salt bath heating provides excellent results. These salt baths contain different compositions of BaCl2, NaCl2, and KCl as well as additional additives to avoid decarburization. The higher the working temperature, the higher the content of BaCl2 usually is. Higher additions of CaCl2 are typically used in salt baths for the quenching step.

For more information, click on the link below (subscription required). Then scroll to Figure 2.

R Schneider; R. Mesquita; W Schützenhöfer, Distortion in Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Rolled Alloys celebrates 70 years in the thermal processing industry

Rolled Alloys, Windsor, Conn., is celebrating 70 years in the thermal processing industry. 

The company was founded in 1953 by introducing RA330 as a wrought replacement to cast HT.

Due to RA330’s versatility and availability, it remains the most widely used wrought alloy by commercial heat treaters. Although RA330 exhibits excellent features, there may be better choices for an application. With this being the case, we offer a wide range of heat-resistant alloys to best suit the needs of your application.

Besides this, RA 602 CA is an alloy developed specifically for the highest temperature process, requiring strength and resistance to atmospheres. 

One last alloy worth discussing is RA253MA. RA253MA is a lean, heat-resistant stainless steel with high strength and oxidation resistance. With excellent high-temperature properties and low nickel content, RA253MA is a cost-effective material that thermal processors frequently utilize for open-air applications.

https://www.rolledalloys.com/70-years-in-the-thermal-processing-industry/

Steel Dynamics named one of America’s best employers for women by Forbes

Steel Dynamics, Fort Wayne, Ind., has been named one of America’s Best Employers for Women for 2023 by Forbes. Steel Dynamics was the only steel producer receiving this designation.

“We are appreciative and honored by this recognition,” said Mark D. Millett, chairman and chief executive officer. “Our people are the foundation of our success and our most important resource. We strive to create a welcoming, open, and inclusive environment. We value our team members, creating meaningful opportunities for growth, leadership development, and career advancement. We believe empowering our people and providing them with the necessary tools for success creates significant value for everyone and will drive our continued success.”

Forbes partnered with Statista to compile the list of America’s Best Employers for Women. Statista surveyed over 60,000 U.S. employees working for companies with a minimum of 1,000 employees. More than 40,000 women were asked to rate their company in areas such as working environment, salary and employee diversity, and then whether they would recommend their company to a friend or family member.

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Special fasteners to be processed in a Seco/Warwick vacuum furnace

Seco/Warwick, Meadville, Pa., will deliver a  Vector vacuum furnace to a plant producing highly advanced fasteners for the largest manufacturers in the aerospace industry. 

The machine will process self-locking nuts, nut plates, barrel nuts, stud nuts, spline nuts, clamp nuts, as well as a wide range of washers and flanges. The Italian Partner is an innovator in the field of comprehensive fastening solutions. The Vector furnace will become part of a modern production plant, increasing not only its efficiency, but also guaranteeing thermally treated fasteners of the highest quality.

The furnace on order is a standard solution perfectly suited to aviation industry needs. Thanks to a very refined design without any additional modifications, the furnace will perform at high operating temperatures, up to 1300°C.

The furnace on order is equipped with a dew point sensor for each of the gases. It is a system solving one of heat treatment’s very critical requirements, which is to control the quality/purity of the gas used during the process. Vector also features a partial pressure control system which helps prevent evaporation and sublimation of alloying elements from the load surface during the vacuum heat treatment.

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Wisconsin Oven ships curing conveyor oven to aerospace industry

Wisconsin Oven Corporation, East Troy, Wis., has announced the shipment of one belt conveyor oven that will be used for curing polystyrene on aluminum parts for the aerospace industry.

This industrial conveyor oven has a maximum temperature rating of 300° F and interior chamber dimensions of 5’4” W x 8’4” L x 6” H. The recirculation system is designed with a top-down airflow configuration and utilizes a 10,000 CFM @ 10 HP blower. Guaranteed temperature uniformity of ±10° F at 210° F was documented with a temperature uniformity test.

The conveyor system is a continuous belt style and utilizes an Allen-Bradley variable frequency drive that allows for speed adjustments. A digital screen on the control panel door displays the conveyor speed during operation. The oven temperature and conveyor speed are controlled by a Watlow F4T digital controller located on the control panel door with PID control and adaptive turning.

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One Minute Mentor: Distortion in Tool Steels

Distortion in tool steels encompasses all irreversible dimensional changes. There are two main types: size distortion and shape distortion. Size distortion involves expansion or contraction in volume or linear dimensions without changes in geometrical form. Shape distortion entails changes in curvature or angular relations, as in twisting, bending, and/or nonsymmetrical changes in dimensions. In most cases both types of distortion occur during a heat-treatment operation.

Some of the main interactions occur between temperature, microstructure, and stress/strain. Especially for tool steels these interactions are mainly influenced by the carbon content in the steel matrix, the types and relative amounts of the alloying elements, and the carbide formation/transformation/precipitation characteristics of the alloy system.

For more information, click on the link below (subscription required). Then scroll to Figure 1..

R Schneider; R. Mesquita; W Schützenhöfer, Distortion in Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

One Minute Mentor: Plasma Nitriding Equipment

Cold-walled (double-walled water-cooled) systems were the first generation of plasma nitriding furnaces. This technology is also a vacuum-based process but employs the principle of glow discharge to provide energy for heating and nitriding at one time. Therefore, the independent control of the temperature stability and the nitriding intensity is not possible because both processes are using the same energy source—the plasma.

The hot-wall plasma nitriding furnaces, the next generation of cold-wall ion nitriding systems, are mainly used and built now. This system ensures optimal nitriding quality by fulfilling the highest demands on temperature and nitriding process control. The big advantage of this technology is the separation of the control of the heating and the plasma nitriding parameters. 

For more information, click on the link below (subscription required). Then scroll to Figure 26

R Schneider; R. Mesquita; H. Altena; T. Müller; P. Seemann, Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Seco/Warwick delivers Vector vacuum furnace to revolver manufacturer

Seco/Warwick, Meadville, Pa.,  received another order for the supply of a Vector vacuum furnace to a South American international manufacturer of weapons and military equipment. The furnace will process various components including barrels, reels, locks, and firearm magazines, which are expected to be reliable, of the highest quality, and perform with outstanding resistance to negative external conditions.

This will be the second solution of this type in the South American defense industry leader’s internal hardening plant. It is a single-chamber gas-cooled vacuum furnace which can be used for a variety of metal heat treatment processes and applications. This solution has been adapted to the customer’s requirements so that it is as effective as possible at delivering the precision heat treatment results required for quality weaponry.

Thanks to the large working space (900x900x1200 mm), the Vector system is designed to process quite large elements. A characteristic feature of the design is convection heating, which improves heat transfer efficiency when heating at lower temperatures, and directional cooling, which enables differentiated cooling of problematic parts in terms of shapes.

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Constellium to sell three german extrusion plants to Vaessen Aluminium

Constellium, Paris,  announced that it signed a binding agreement with Vaessen Aluminium for the sale of three of Constellium’s soft alloy extrusion facilities located in Landau, Crailsheim and Burg in Germany for a total cash consideration of €48.8 million.

With nearly 450 employees, the three Constellium plants specialize in soft alloy extruded products for the Building & Construction, Transportation and Industry markets in Europe.

Vaessen Aluminium belongs to a longstanding family-owned industrial group, headquartered in Belgium, active in aluminum billets and profiles (E-Max), in lighting and ceiling (Kreon) and in wall cladding (Limeparts Drooghmans).

The transaction is expected to close in the second half of 2023 and is subject to customary closing conditions and regulatory approval.

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Lehigh’s summer engineering institute students tour Solar Atmospheres

Solar Atmospheres, Souderton, Pa., hosted over 40 high school students enrolled in the Summer Engineering Institute (SEI) at Lehigh University. The SEI program, under the guidance of Director Dr. Laura Moyer, is a two-week residential program, running two sessions back to back. 

Students are nominated by faculty of local high schools, and the program specifically targets under-represented groups including girls, first-generation students, and students who might otherwise have limited opportunities to study in the fields of science, technology, engineering, and math (STEM).

Solar Atmospheres provided a tour of the campus, exhibiting materials and processes for intriguing applications in a variety of markets. The students experienced a manufacturing setting encompassing related topics from their curriculum, gaining a better understanding of heat treating and manufacturing, and how cutting edge technology reshapes centuries-old processes.

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