Ageing of Cast Austenitic Stainless Steels (CASS) was attributed to the decomposition of the ferrite by spinodal decomposition and precipitation of G-phase particles. This leads to an increase in hardness and a decrease in Charpy-impact energy. It is possible to restore the mechanical properties of these steels by annealing treatment above the Fe-Cr miscibility gap in order to dissolve α’ phase. In this work, an annealing treatment for 2 h at 550°C followed by water quenching was applied to various Mo-free and Mo-bearing steels. This treatment allowed to restore almost completely the mechanical properties of Mo-free steels and partly Mo-bearing steels regardless of the initial ageing time. The mechanical property changes were attributed to the complete dissolution of spinodal decomposition and complete or partial dissolution of G-phase particles. After annealing, a re-ageing kinetics was studied. The preexisting G-phase particles have minor influence on the kinetic of spinodal decomposition until 2,400 h at 400°C.

铸造奥氏体不锈钢（CASS）的时效归因于通过旋节线的分解和G相颗粒的沉淀而使铁素体分解。这导致硬度增加和夏比冲击能降低。通过在Fe-Cr可混溶间隙以上进行退火处理以溶解α'相，可以恢复这些钢的机械性能。在这项工作中，对各种不含Mo和含Mo的钢在550°C退火2 h，然后进行水淬。不管初始时效时间如何，这种处理都能使无钼钢和部分含钼钢几乎完全恢复机械性能。力学性能的变化归因于旋节线分解的完全溶解和G相颗粒的完全或部分溶解。退火后，研究了再老化动力学。预先存在的G相粒子对旋节线分解动力学的影响很小，直到在400°C下持续2,400 h。