Effect of Deep-Cryogenic Treatment on High Speed Steel Properties

Abstract

Advantages of deep-cryogenic treatment over standard heat treatment of high speed steels for the purpose of obtaining better properties are quoted in an increasing number of scientific articles. This article deals with the most important improvements of high speed steel properties achieved by using deep-cryogenic treatment. The effect of deep-cryogenic treatment on impact and fracture toughness, on erosion wear resistance, and on the material microstructure has been tested on samples made of the PM S390 MC high speed steel. A set of test samples was heat treated by conventional methods (hardened and three times high temperature tempered), and the other set was deep cryogenic treated. From the results, it can be concluded that the application of deep-cryogenic treatment results in significantly higher wear resistance of high speed steels, but no significant improvements in toughness have been observed.

Keywords:

• Austenitizing temperature
• Deep-cryogenic treatment
• Eta-carbides
• Hardness
• High speed steel
• Impact energy
• K _Ic fracture toughness
• PM S390 MC
• Precipitation
• Residual austenite
• Secondary hardening
• Secondary martensite
• Solid erosion
• Tempering
• Wear resistance