Effect of Cryogenic and QPQ Compound Treatment on the Microstructures and Performance of High Speed Steel

摘要

China’s High-speed steel cutting tools hold a considerable share in the global market.However,the overproduction of low-end HSS tools causes serious resource waste and low efficiency,which has become one of the major problems in the tool industry in China.So a new Surface Modification technology is developed,which can make the low-end HSS tools into the high-end ones.On the analysis of the mechanism of cryogenic and quenching-polish-quenching（QPQ）,the cryogenic and QPQ compound treatment are studied by using φ8 HSS（M2） drills.The nitriding layer and the base of the drill bit are Studied and analyzed,and the mechanism of compound treatment is discussed by the technological parameters adjustment and the combination test of cryogenic,nitrogen,tempering procedures,and several analysis methods such as the optics metallographic microscope,the scanning electronic microscope （SEM）,X-ray diffraction and micro hardness.The cutting test is done on the drills by cryogenic treatment,QPQ treatment and cryogenic and QPQ compound treatment separately.The results indicates that the cutting life of HSS （M2） drill can be increased dramatically by cryogenic and QPQ compound treatment.