Effect of Irradiation on Austenite Phase in Thermally Aged 308 Stainless Steel Weld Metal

Abstract

Abstract In this study, 308 stainless steel weld metals aged at 400°C for 7000h were irradiated at 400°C to different fluences with 240keV proton to study the effects of radiation on austenite phase. The microstructural change was examined by transmission electron microscope (TEM), and the hardness change was measured with a nano-indentation tester. It was found that bubbles and dislocation loops were formed in the austenite phase, and their size and numerical density increased with the irradiation dose. The hardness of the austenite phase also increased with the irradiation fluence. According to the statistical results of microstructural features, the dispersed barrier hardening model was used to correlate the hardness change with the microstructure evolution. Although the calculated value of hardness change was lower than the measured value, the variation trend of the calculated hardness values was in good agreement with that of the measured values.