Mechanical Properties and Microstructure of High Speed Steel W18Cr4V after Repeated Cryogenic Treatment

The mechnical properties and microstructure of high speed steel W18Cr4V after repeated cryogenic treatment were studied by means of experimental measurements of mechnical properties,SEM and TEM.The results show that compared with once long cryogenic treatment,the mechnical properties significantly increased and the ultra-fine dispersed carbide particles precipitated on the twin bands and dislocation lines of martensite after repeated cryogenic treatment.The repeated cryogenic treatment can accelerate carbide particles to decrease in size and to distribute homogeneously,therefore,the effect of repeated cryogenic treatment is better than that of single long cryogenic treatment.