Mössbauer Effect Study on the Mechanism of the Phase Decomposition in Iron-Chromium Alloys

Abstract

The concentration and temperature dependences of the incubation time, the analysis of the transformation rate based on the Johnson-Mehl equation, and the time evolution of the Mössbauer spectrum suggest that the nucleation and growth process plays a dominant role in the phase decomposition of Fe–Cr alloys around 748 K in the concentration range from 21 to 36.3%Cr. The spinodal decomposition becomes predominant in the concentration range from 42 to about 60%Cr. The decomposition mode shows a gradual transition from the nucleation and growth to the spinodal decomposition with increasing Cr content.