After austenitizing and quenching, tool steels are sometimes subjected to cold treatment at approximately –80°C, followed by tempering. Primarily, the cold treatment is done to increase strength, improve dimensional or microstructure stability, and improve wear resistance. These benefits are due to the transformation of retained austenite to martensite. Some studies show that lowering the cold treatment temperature below
–100°C does not significantly increase the amount of retained austenite-to-martensite transformation—therefore it does not result in additional benefits. However, other studies show that compared to cold treatment (–80°C), cryogenic treatment (–190°C) further improves wear resistance. For help determining which subzero quenching process can help you produce the best parts, call us at 800-654-4567.