0.29V-0.09Ta RAFM钢辐照条件下空洞演化的实验和理论研究

Experimental and theoretical analysis of void evolution during irradiation in 0.29V-0.09Ta RAFM steel

摘要:

为研究辐照条件下空洞的演化,分别在200 °C, 350 °C和550 °C对低活化铁素体/马氏体钢(RAFM)进行He离子辐照。实验结果显示辐照损伤沿深度呈钟型分布,空洞的尺寸和密度均与空位产生率正相关。随着辐照温度升高,空洞的尺寸增大,密度降低,高温下可以观察到空洞在晶界的聚集和无空洞区(VDZs),在550 °C可以观察到方形空洞。使用相场模型模拟空洞的演化机制,模拟结果显示辐照条件下空洞演化可以分为孕育、形核和生长三个阶段,空洞界面能的各项异性是空洞形状的可能原因。

Abstract:

Helium ion irradiation at 200 °C, 350 °C and 550 °C was performed on a reduced activation ferritic/martensitic (RAFM) steel to investigate the evolution of voids during irradiation. Experimental results showed that radiation damage had a bell-shape distribution along the depth. Both void size and density increased as vacancy production rate increased. When irradiation temperature rose, void size increased and void density decreased. Faceted voids were observed at 550 °C. Voids aggregation at grain boundaries (GBs) and void denuded zones (VDZs) were observed at high temperatures. A phase field model was employed to investigate the void evolution mechanism. The simulation results showed that the void shape may be attributed anisotropic void interface energy. During irradiation, as time goes on, void evolution can be divided into three stages: incubation stage, nucleation stage and growth stage.