Phase-field modelling of spinodal decomposition with G-phase precipitation during ageing  

作　　者：SHI JiaQing SHEN Yao 

机构地区：[1]The State Key Lab of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China [2]School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China

出　　处：《Science China(Technological Sciences)》2021年第12期2568-2576,共9页中国科学（技术科学英文版）

基　　金：the National Key Research and Development Program of China(Grant No.2017YFB0702201)。

摘　　要：The duplex stainless steels(DSSs)are susceptible to thermal ageing embrittlement due to the spinodal decomposition and Gphase precipitation in the ferritic phase.This study presents a ternary(Fe-Cr-Ni)phase-field model for the simulation of spinodal decomposition with concurrent G-phase precipitation.Two Cahn-Hilliard equations and one Ginzburg-Landau equation are used in the model to describe the diffusion of Cr,Ni,and the growth of G-phase,respectively.The model is able to generate a spinodally-interconnected structure with G-phase particles near theα-α′interfaces,similar to experimental observations.The kinetic synergy between spinodal decomposition and G-phase precipitation is discussed.The simulation results indicate that Gphase can enhance the evolution of spinodal decomposition by occupying the volume where the decomposition could otherwise occur,and that the system’s elastic strain energy is largely contributed by G-phase rather than spinodal decomposition.These results would help in better understanding the states of the materials for plant structural integrity assessment and life management.

关 键 词：FERRITE DSSS spinodal decomposition G-phase phase-field model 

分 类 号：TG161[金属学及工艺—热处理]