Influence of Cryogenic Treatment on Grinding Residual Stress of WC-Co Cemented Carbides

The changes in residual surface stress state significantly affect the mechanical behaviour of the materials. In this paper, the effect of cryogenic treatment on grinding residual stress of ultra-fine grained WC-Co hardmetals has been investigated by measuring the residual stress of ground carbide surfaces before and after cryogenic treatment. The results show that the cryogenic treatment can relieve the residual stresses of ground carbide surfaces. Relaxation degree of residual stresses is highly dependent on the process parameters of cryogenic treatment, such as soaking temperature, cooling rate and warming rate. The relaxation rate of residual stresses decreases with the decreasing of soaking temperature, warming rate or increasing cooling rate, and does not change obviously with the soaking time.