High temperature (550 °C) He ions irradiation was performed on nanostructured (NS) and coarsen-grained (CG) reduced activation steel to investigate the effects of GBs/interfaces on the formation of bubbles during irradiation. Experimental results showed that He bubbles were preferentially trapped at dislocations and/or grain boundaries (GBs) for both of the samples. Void denuded zones (VDZs) were observed in the CG samples, while VDZs near GBs were unobvious in NS sample. However, both the average bubble size and the bubble density in peak damage region of the CG sample were significantly larger than that observed in the NS sample, which indicated that GBs play an important role during the irradiation, and the NS steel had better irradiation resistance than its CG counterpart.

在纳米结构（NS）和粗晶粒（CG）还原活化钢上进行了高温（550°C）He离子辐照，以研究辐照期间GBs /界面对气泡形成的影响。实验结果表明，两个样品的He气泡都优先被捕获在位错和/或晶界（GBs）处。在CG样品中观察到了空洞剥蚀区（VDZs），而在NS样品中，GBs附近的VDZs并不明显。但是，CG样品的平均气泡大小和峰值损伤区域的气泡密度均显着大于NS样品，这表明GBs在辐照过程中起着重要作用，NS钢具有更好的辐照强度比它的CG对手