Role of Cooling Rate on the Substructure of Eutectic M7C3 Carbides in Hypereutectoid Fe-Cr-C Alloy 8Cr13MoV

摘要

The control of primary M7C3 carbides is significant for improving the performance of hypoeutectic Fe-Cr-C alloy. In this paper, the growth mechanism of primary M7C3 carbides and the effect of cooling rate on primary M7C3 carbides in 8Cr13MoV were ascertained by electron backscatter diffraction and scanning electron microscopy. The results showed that the morphology of primary M7C3 carbides was multiple granular instead of overall blocky. Increasing the cooling rate enabled refining the size of carbide grains, changing the morphology of carbide grains and promoting the generation of eutectic carbides, despite not changing the agglomeration and coalescence behaviors of carbide grains.