Thermal aging experiments on a 9Cr-ODS steel were carried out at 700 °C with a period from 100 up to 10000 h, and the effects on mechanical properties and microstructural evolutions were investigated. It was found that hardness and tensile properties exhibited negligible degradation by thermal aging. The mixed ductile and brittle fracture modes in the tensile specimens remained almost no change. Although a slight recovery of grains/subgrain structures and dislocations took place, the homogeneously dispersed nano-size oxides with an ultrahigh density in matrix were not affected during the thermal aging. However, a significant coarsening of carbides around grain/subgrain boundaries appeared. Benefited from the extreme stability of nano-size oxides, the 9Cr-ODS steel possesses the excellent thermal stability of mechanical properties exposed to the elevated temperature of 700 °C up to 10000 h.

9Cr-ODS钢在700°C下进行了100到10000 h的热时效试验，并研究了其对力学性能和微观组织演变的影响。发现硬度和拉伸性能由于热老化而表现出可忽略的劣化。拉伸试样中的混合的韧性和脆性断裂模式几乎保持不变。尽管发生了晶粒/亚晶粒结构和位错的轻微恢复，但在热时效过程中并未影响在基体中具有超高密度的均匀分散的纳米级氧化物。但是，晶粒/亚晶粒边界周围的碳化物出现了明显的粗化。受益于纳米级氧化物的极高稳定性，