Experiment of process on deep cryogenic treatment for W6Mo5Cr4V2 HSS drill

The deep cryogenic treatment process of W6Mo5Cr4V2 High Speed Steel(HSS)was studied by orthogonal experiment method.Analysed the effect of various cryogenic treatment process parameters on mechanical properties,and observed microstructure before and after deep cryogenic treatment by the scanning electron microscope.The results show that the first factor affecting deep cryogenic treatment is soaking temperature,the second one is soaking time and the third one is tempering temperature.Deep cryogenic treatment enhances the transformation of austenite tomartensite,and distributable carbides are precipitated from martensite.Deep cryogenic treatment increases hardness and enhances wear resistance of the twist drill.