One Minute Mentor: Salt Bath Furnaces

August 15, 2023
Source: ASM International

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


Source: ASM International

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/

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


Source: ASM International

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.

Read further here.

One Minute Mentor: Plasma Nitriding Equipment

August 2, 2023
Source: ASM International

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


Source: ASM International

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


Source: ASM International

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.

Read further here.

Lehigh’s summer engineering institute students tour Solar Atmospheres


Source: ASM International

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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Nitrex provides nitrocarburizing system to New Zealand heat treater


Source: ASM International

Nitrex provides nitrocarburizing system to New Zealand heat treater

Nitrex, Quebec, has announced that they have provided a nitrocarburizing system to Heat Treatments, a leading provider of commercial heat treatment services in New Zealand and one of Nitrex’s earliest customers.

Heat Treatments’ partnership with Nitrex dates to 1992 when they purchased its first Nitrex system with Nitreg nitriding capabilities. As operations grew, the company later added a second system in 2004 for nitrocarburizing and post-oxidation treatments. Contrary to the first two systems, which are identical pit furnaces, the latest addition, an NXK series, features the furnace and control panel mounted on an integral platform. Delivery, installation, and startup time and costs are reduced with this design. The NXK-812 model is designed to treat workloads weighing up to 1200 kg, with a diameter of 800 mm (31.5″) and a height of 1200 mm (47.25″). The system is equipped with advanced process technologies, including Nitreg-C controlled nitrocarburizing and ONC post-oxidation, which provide precise control and consistent results.

https://www.nitrex.com/

One Minute Mentor: Plasma Nitriding Equipment

July 9, 2023
Source: ASM International

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. The heating and temperature control of hot-wall plasma nitriding furnaces is realized by several independent heating/cooling zones, which guarantees optimal temperature homogeneity

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

Evolution on the microstructure and mechanical properties of a new multicomponent near-Alpha Titanium Alloy after rolling and heat treatments


Source: ASM International

Evolution on the microstructure and mechanical properties of a new multicomponent near-Alpha Titanium Alloy after rolling and heat treatments

Beijing University of Technology, China, presented the microstructure and mechanical properties of a new type of multi-component near-α titanium alloy sheet after rolling, 700°C aging, and 800°C aging in a new paper.

 The results show that the strength of the alloy after aging at 700°C increases from 1156 MPa to 1304 MPa, respectively, but decreases to 1246 MPa with the aging temperature increasing. The ductility of the alloy aged at 700°C is lower than that of the rolled state, but the ductility increases slightly with the aging temperature increasing. The effect of aging heat treatment on the microstructure and precipitation behavior of alloy plates has been studied and compared with alloys before aging. 

After heat treatment, the content of primary α decreases from 25% to 5%, respectively. Two kinds of silicide precipitate at different positions, with the large-size spherical silicide being (Ti, Zr, Nb)5Si3, and the small-size fusiform silicide being (Ti, Zr, Nb)6Si3, respectively. Ti3Al was precipitated in the primary α phase, during the aging process. The silicides exhibit the strengthening effect on the alloy, but the effect weakens when the silicides grow up. The loss in ductility is mainly attributed to the precipitation of the α2 phase after aging treatment. However, ductility is improved after applying higher aging temperatures as the size of the α2 phase becomes smaller, and the distribution of them tends to become dispersed.

Read further here