Effect of Heat Treatment on Radiation Damage Resistance of Weld Joint of CLAM Steel

In order to improve the irradiation damage resistance and irradiation hardening resistance of the welds of China low activation martensitic (CLAM) steel, the CLAM steel welds without and with heat treatment exposed to He+ with energy of 70 keV to a dose of 1×1017 ions/cm2 at room temperature were analyzed by AFM, SEM, grazing incident X-ray diffraction (GIXRD), tensile test and nano-indentation techniques. The results show that micro defects such as voids are formed in the two kinds of weld metals after ion irradiation. After heat treatment, the weld of CLAM steel has the characteristics of smaller grain structure and higher grain boundary density, which hinders the mutual aggregation of micro defects. The defects formed in the heat treated weld are distributed more evenly and smaller in size, the weld always has better mechanical properties before and after irradiation. It is a feasible idea and method to refine weld grains through heat treatment process for improving the resistant ability of weld irradiation damage and irradiation hardening. © 2023 Rare Metals Materials and Engineering Press. All rights reserved.