Influence of Quenching Temperature on Microstructure and Properties of Cr5 steel

Abstract

The microstructure (before and after quenching), phase (before quenching), carbide content and hardness were studied by scanning electron microscopy, X-ray diffraction, optical software and Rockwell hardness tester. The results indicate that carbides of Cr5 steel have different morphology features and obvious aggregation phenomenon, most carbides dissolve in the matrix after quenching, the carbides of not dissolving with small particles distribute in the martensite. The style of carbides before quenching have M 7 C 3 、M 23 C 6 and M 3 C 2. volume fraction of carbides gradually reduce with quenching temperature increase, and the temperature of carbides dissolving in the matrix is 970C. Cr5 steel hardness increases and later decreases with the quenching temperature increases, the peak hardness (54HRC) is achieved in the 970C.