低活化钢的氦离子辐照损伤行为

Helium ion irradiation damage behavior in a reduced activation steel

利用氦离子辐照研究了不同辐照温度下低活化钢的辐照损伤行为,采用透射电镜和纳米压痕仪测量和表征了辐照引起的缺陷组织和硬化效应,并分析了两者之间的影响关系。结果表明,氦离子辐照造成的组织变化主要包括气泡和MC相的粗化。气泡在晶界上发生聚集,辐照剂量越大,气泡密度越高;辐照温度越高,气泡尺寸越大、密度越低。辐照之后,低活化钢硬度提高,且辐照温度上升,硬化效应降低。辐照硬化值与缺陷组织的尺寸和密度相关,高密度的小尺寸气泡是氦离子辐照硬化的主要因素,辐照温度升高,气泡密度降低,辐照硬化减弱。

Irradiation damage behavior of a reduced activation steel was studied by carrying out helium ion irradiation at different temperatures,and the irradiation-induced defect microstructure and hardening effect were observed and analyzed by means of transmission electron microscope(TEM)and nanoindenter respectively.The results show that the defect microstructure induced by irradiation mainly includes bubbles and coarsening of MCprecipitate.Bubbles aggregate on grain boundaries,the bubble density increases with the increase of irradiation intensity,and the bubble size increases while the density decreases with the increase of irradiation temperature.The hardness of the reduced activation steel increases after irradiation,while the temperature rising weakens this effect.Irradiation hardening is related to size and density of defect microstructure,and the high density of small bubbles contributes mainly to hardening.As the irradiation temperature rises,the bubble density decreases sharply,which weakens irradiation hardening.