Microstructure of Cr–V–Mo Steel Processed by Recrystallization and Partial Melting and Its Effect on Mechanical Properties

Abstract

Recrystallization and partial melting (RAP) experiments were conducted on Cr–V–Mo steel using a multistage hot compression test machine. The dendritic microstructure of the cast material was refined owing to the recrystallization and austenization that occurred during RAP. The refinement of the microstructure is affected by the preparation of the initial cast billet. A higher cooling rate during casting results in a finer RAP-processed globular microstructure. Owing to the core segregation during casting and the phase segregation during RAP, alloying elements are distributed inhomogeneously in RAP-processed specimens. Optimal post heat treatments were designed to increase the homogeneity of the microstructure of RAP-processed specimens. Quenching from 1323 K followed by tempering at 833 K improve the consistency of the Vickers hardness, toughness, and high-temperature wear resistance of RAP-processed specimens.