The research on process of deep cryogenic treatment for W9Mo3Cr4V HSS drill

It studies the deep cryogenic treatment process of W9Mo3Cr4V HSS by orthogonal ex-periment method,and analyses the effects of various cryogenic treatment process parameters on mechanical properties,and observes microstructure before and after deep cryogenic treatment by the SEM.The results shows that the effect of soaking temperature on the properties of drill is strongest,the soaking time and the cooling rate is secondary and tertiary.Deep cryogenic treatment enhances the transformation of austenite to martensite,and distributable carbides are precipitated from martensite,so deep cryogenic treatment in-crease hardness and enhance wear resistance of the twist drill.