双相不锈钢高温时效σ相析出行为研究进展

Research Development of σ Phase Precipitation in High Temperature Aging on Duplex Stainless Steel

双相不锈钢高温热加工过程中,σ脆性相的快速析出将损害其力学性能和耐腐蚀性能。采取合适的热加工工艺抑制σ相的快速析出具有重要意义。简要综述了高温时效双相不锈钢析出相的特点,高温时效过程中σ相的析出机理、σ相析出动力学、σ相析出影响因素以及σ相析出对材料力学性能和耐腐蚀性能的影响。化学成分、铁素体晶粒尺寸和体积分数,以及相应的热处理工艺等将影响高温条件下铁素体向σ相的分解。升高固溶温度,能在一定程度抑制高温时效过程中σ相的析出。

The fast precipitation of σ phase can impair the mechanical property and corrosion resistance of duplex stainless steel（DSS） during hot working process of high temperature. Therefore, it is important to suppress the precipitation of σ phase by taking appropriate hot working technology. The research and development on σ phase precipitation behavior of DSS in high temperature are summered, including property of σ phase precipitation, mechanism of σ phase precipitation, σ phase precipitation kinetics, factors that affect the σ phase precipitation, and the effect of σ phase precipitation on mechanical property and corrosion resistance. Chemical composition, ferrite grain size and volume fraction, and the corresponding heat treatment process, etc. , will affect the decomposition of ferrite phase to phase in high temperature working process. Increasing solution treatment temperature can suppress the σ phase precipitation to some degree in high temperature aging.