The effect of thermal aging at 475 °C and 750 °C of Z3CN20.09M cast duplex stainless steel (CDSS) on microstructure, mechanical and intergranular corrosion properties were investigated by transmission electron microscope (TEM), nano indenter, scanning electron microscope (SEM) and corrosion fatigue test system. The result indicated that the spinodal decomposition and G precipitated were occurred after aged at 475 °C, as well as sigma precipitated at 750 °C. The microstructure degeneration of ferrite was saturated after aged for 2000h and 200 h at 475 °C and 750 °C respectively. The mechanical properties, intergranular corrosion resistance and corrosion fatigue lives were continuing deteriorated with increasing the aging time at both temperatures. The difference of the degeneration mechanisms of Z3CN20.09M CDSS aged at 475 °C and 750 °C was analyzed.

采用透射电子显微镜（TEM）、纳米压头、扫描电子显微镜（SEM）研究了Z3CN20.09M铸造双相不锈钢（CDSS）475℃和750℃热时效对微观结构、力学性能和晶间腐蚀性能的影响。 ) 和腐蚀疲劳试验系统。结果表明，在475℃时效后发生了旋节线分解和G沉淀，在750℃时出现了σ沉淀。分别在475℃和750℃时效2000h和200h后，铁素体的显微组织退化达到饱和。机械性能、耐晶间腐蚀性能和腐蚀疲劳寿命随着两种温度下老化时间的增加而持续恶化。Z3CN20 变性机制的差异。