Voids healing and carbide refinement of cold rolled M50 bearing steel by electropulsing treatment.

The voids caused by the cold rolling (CR) quite deteriorates the final performance of M50 bearing steel. In this work, the effect of electropulsing treatment (EPT) on the voids has been investigated, finding that the nano-size voids around carbides have been extensively healed. Moreover, it is interesting to find that the Cr-rich carbides are partially dissolved and consequently refined by EPT, which could be attributed to the decreased thermodynamic dissolution barriers and accelerated kinetic diffusion of carbon atoms towards dislocation. These results inspire people to develop a novel strategy (CR + EPT) to fully take advantage of CR and tailor the carbides size in bearing steels.