Effect of directed treatment of austenitic high-nickel alloys on its tendency to helium embrittlement

The effect of dislocation structure on helium distribution in the sample irradiated at T < 100 deg C by 50 MeV α-particles was studied on the example of the Kh20N45M4B alloy. Tensile test of irradiated and control samples revealed a shaprp drop of specific elongation in irradiated samples particularly at high temperatures. Fracture in irradiated samples is exclusively of intercrystalline nature that is explained by helium bubbling along the grain boundaries. It is shown that production of a stable dislocation structure by material deformation promotes suppression of high-temperature helium embrittlement at the expense of more uniform distribution of helium