热处理对CLAM钢焊缝抗辐照损伤性能的研究

Effect of heat treatment on radiation damage resistance of weld joint of CLAM steeld

摘要:

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，采用原子力显微镜（Atomic Force Microscope, AFM）、扫描电子显微镜（Scanning Electron Microscope, SEM）、透射电子显微镜（Transmission Electron Microscope, TEM）、掠入射X射线衍射（Grazing Incidence X-ray Diffraction, GIXRD）、拉伸和纳米压痕技术等方法，对热处理前及热处理后的CLAM钢焊缝在室温下经能量为70-KeV、剂量为1×1017 ions/cm2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，离子辐照后，热处理前及热处理后焊缝金属中均产生了空洞等微观缺陷，力学性能呈现不同程度的降低。热处理后的CLAM钢焊缝晶粒组织更小、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，该焊缝在辐照前及辐照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辐照硬化的能力，是一种可行的思路与方法。

Abstract:

In order to improve the irradiation damage resistance and irradiation hardening resistance of the welds of China Low Activation Martensitic steel (CLAM), the CLAM steel welds before and after heat treatment exposed to He+ with energy of 70-KeV to a dose of 1×1017 ions/cm2 at room temperature were analyzed by atomic force microscopy (AFM), scanning electron microscopy (SEM), grazing incident X-ray diffraction (GIXRD), tensile and nano-indentation techniques. The results show that micro defects such as voids are produced in different weld metals after ion irradiation, and the mechanical properties are reduced in varying degrees. 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 weld are more evenly distributed 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 grain through heat treatment process and improve the ability of weld to resist irradiation damage and irradiation hardening.