热处理对CLAM钢焊缝抗辐照损伤性能影响的研究

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

为提高中国低活化马氏体钢(China low activation martensitic steel,CLAM)焊缝抗辐照损伤及辐照硬化的能力,采用AFM、SEM、TEM、掠入射X射线衍射(grazing incidence X-ray diffraction,GIXRD)、拉伸试验和纳米压痕技术等方法,对热处理前后的CLAM钢焊缝在室温下经能量为70 keV、剂量为1×10^(17) ion/cm^(2)的He^(+)辐照后的辐照损伤情况及力学性能进行了研究。研究结果表明,已热处理与未热处理2种焊缝经离子辐照后,焊缝金属中均产生了空洞等微观缺陷。热处理后的CLAM钢焊缝具有晶粒组织更小、晶界密度更高的特点,阻碍了微观缺陷的相互聚集,焊缝内形成的缺陷分布更均匀、尺寸更小,该焊缝在辐照前后始终具有更优异的力学性能。通过热处理工艺来细化焊缝晶粒,提高焊缝抗辐照损伤及抗辐照硬化的能力,是一种可行的思路与方法。

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 1×10^(17) ions/cm^(2) 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.