Effect of variable heat treatment modes on microstructures of Fe-Cr-B cast iron alloy

Abstract

The effect of heat treatment mode on the microstructure of Fe-Cr-B cast iron alloys was investigated in this paper by comparing the difference of precipitation patterns of secondary particles after thermal cycling treatment (TCT) with those after normal heat treatment (NHT). No obvious differences were found in precipitation patterns of secondary particles between TCT and NHT when experimental temperature was below Ar1. However, when temperature was over Ar1, there were significant differences, with secondary particles prominently segregated at the grain boundaries under TCT, while the particles evenly distributed in the matrix under NHT. The reason for the microstructure differences could be associated with the development of non-equilibrium segregation of boron during TCT.

Keywords

• heat treatment mode
• microstructures
• Fe-Cr-B cast irons
• non-equilibrium segregation of boron