Effect of Spheroidizing Annealing in Combination with Alternating Magnetic Field on Microstructure and Mechanical Properties of GCr15 Bearing Steel

Microstructures and mechanical properties after spheroidizing annealing (SA) of GCr15 bearing steel with and without an alternating magnetic field (AMF) were investigated. It was found that the application of the AMF at the austenitizing stage promoted the dissolution of carbides, accelerated the austenitizing process and increased the hardness of the quenched sample. After isothermal annealing, the carbides in the sample with an AMF more uniformly distributed and became finer in comparison with those without an AMF. The average hardness of the sample treated in the AMF was lower than that without an AMF. The phenomena could be attributed to the enhanced diffusivity in the AMF.