The Research on Process of Deep Cryogenic Treatment for YT15 Carbide Insert

Deep cryogenic treatment (DCT) is a one time permanent process. In DCT, the material is slowly cooled down to the soaking temperature, is held at soaking temperature for a period time, and is heated back to room temperature. DCT process factors have their own effect on the mechanical properties of material. The paper studies the deep cryogenic treatment process of YT15 carbide inserts by orthogonal experiment method, and analyses the effects of various cryogenic treatment process parameters on mechanical properties, and observes microstructure before and after DCT by the scanning electronic microscope (SEM). The results show that the effect of soaking temperature on the properties of inserts is the first factor, the cooling rate and the tempering temperature is secondary and tertiary. Deep cryogenic treatment improves the multi-type martensite transformation of Co. Therefore deep cryogenic treatment increase hardness and enhance wear resistance of the carbide insert.