Effect of He on 12Cr-ODS Ferritic Steel Structural Damage during（He⁺+e^-） Dual-Beam Irradiation

The 12Cr-ODS ferritic steel made by the method of sol-gel was prepared and effect of the interaction between point defects and He on the void swelling was studied by（He⁺+e^-） dual-beam irradiation.At the initial stage of irradiation,a lot of point defect clusters（dark dots） were nucleated.They grew slowly and their number density increased with irradiation dose and the clusters developed to interstitial loop.Also,fine void with high density were formed at different temperature and the void size increased slowly and the number density decreased slowly too with the increasing of irradiation dose.The resultant void swelling at each temperature after 15dPa were less than 0.05%.Thus this 12Cr-ODS ferritic steel showed excellent swelling resistance.The effect of interaction of point defect and He on the behavior of void swelling has been explained by the theory of irradiation damage in the present work.