反应堆压力容器钢晶粒取向对辐照硬化的影响

Effect of Grain Orientation of Reactor Pressure Vessel Steel on Irradiation Hardening

目的探究反应堆压力容器用钢中晶粒取向与辐照硬化的关系。方法选用目前在反应堆压力容器中广泛应用的A508-3钢,首先,采用160 keV铁离子对RPV进行室温辐照,辐照损伤分别达0.2、0.5、1.0、10 dpa。然后,通过纳米压痕技术测量辐照前后样品标定区域的硬度。同时,结合电子背散射衍射对辐照前后样品的硬度标定区域进行晶体取向分析。结果实验对不同晶粒取向的纳米压痕数据进行统计分析,发现当晶粒取向在[001]方向附近时硬度值最大,而当晶粒取向远离[001]方向,即取向距[001]的旋转角从0°增大到90°时,硬度值逐渐减小。结论揭示了RPV辐照硬化可能存在较强的取向依赖性,为RPV的逆向设计提供基础。

This paper aims to investigate the relationship between grain orientation and irradiation hardening in reactor pressure vessel steels.Chinese A508-3 steel,which is currently widely used in reactor pressure vessels,is selected.160 keV Fe-ion irradiation was performed on the pretreated RPV samples under room temperature.The irradiation damage was 0.2,0.5,1 and 10 dpa,respectively.Then the hardness was measured by nano-indentation technique on the marked areas of the samples before and after irradiation.The grain orientation analysis was performed by electron backscatter diffraction on the marked areas of the samples that had been tested for nanoindentation before and after irradiation.The results of nanoindentation results with different grain orientations were statistically analyzed,and the correlation between radiation hardening and grain orientation was found.The nanohardness exhibited the highest value and the grain orientation was near the[001]direction,and It gradually decreased when the grain orientation was away from the[001]direction.Therefore,when the rotation angle of the orientation[001]increased from 0°to 90°,the nanohardness gradually decreased.It is found that the hardness of Chinese RPV steel related to its grain orientation,and there could be a strong orientation dependence of irradiation-induced hardening in it,which provides a basis for reverse design of RPV.