Tensile properties and microstructure of EC316LN irradiated in STIP-II

Abstract Solution-annealed austenitic stainless steel EC316LN was irradiated in the second experiment of the SINQ Target Irradiation Program (STIP-II) to doses between 5.8 and 18.8 dpa at temperatures between 110 and 375 °C. Tensile tests were conducted at room temperature and irradiation temperatures. The irradiation induced significant hardening and embrittlement effects. Although the uniform elongation reduced sharply to less than 1% after irradiation, all the irradiated specimens ruptured in ductile fracture mode. TEM observation shows that the dominant features induced by the irradiation are high-density dislocation loops. Dense helium bubbles with sizes of 1–2 nm were observed in specimens after irradiation to 17.4 dpa at 298 °C and above.