中文摘要：

以采用机械合金化和热等静压法制备的纳米结构9Cr—ODS钢为研究对象，利用高分辨率透射电镜和扫描透射电镜的高角环形暗场像等手段分析了9Cr—ODS钢的微观结构特征；利用400keV离子加速器向9Cr—ODS钢及无ODS的Eurofer97钢中注入4×1017／cm2氦离子，对比了氦泡尺寸．结果表明：纳米结构9Cr—ODS钢的平均晶粒尺寸约0．5μm，存在两种尺寸不同的析出相：超高密度弥散分布的纳米尺度Y2Ti2O7析出相和倾向于在晶界形成的尺寸较大的Mn（Ti）Cr2O4析出相．ODS钢中的氦泡尺寸明显小于Eurofer97钢，说明纳米析出相对粗大氦泡的形成有明显的抑制作用．

英文摘要：

A 9Cr-ODS steel was prepared by mechanical alloying and hot isostatic pressing methods. The microstructures were characterized by high-resolution transmission electron microscopy and high-angle annular dark field scanning transmission electron microscopy （HAADF- STEM）. Helium ions of 4 ×1017/cm2 were respectively implanted into the 9Cr-ODS steel and non-ODS Eurofer97 steel with a 400 keV ion accelerator, and the sizes of helium bubbles in the two steels were observed by HAADF-STEM. The results show that the average grain size of the 9Cr-ODS steel is about 0. 5 μm. Two kinds of precipitates were observed in the ODS steel： high- density nano-size Y/Ti2O7 and large Mn（Ti） Cr2O4 formed mainly at the grain boundaries. The size of the helium bubbles in ODS steels is much more smaller than that in Eurofer97 steel, which means that the nano-size precipitates are helpful to suppress the formation of coarse helium bubbles.