EFFECT OF MN ADDITION ON DECREASE OF CR DEPLETION AT GRAIN-BOUNDARY IN AUSTENITIC ALLOYS IRRADIATED WITH ELECTRONS

Radiation-induced Cr depletion at a grain boundary (GB)is known as one of the major factors to degrade corrosion resistance of austenitic st ainless steel. The effect of 10% Mn addition on prevention of the Cr d epletion was investigated from a viewpoint of volume size factor (VSF) of Cr in the austenitic alloys irradiated with 1 MeV electrons, VSF o f Cr in. solution-annealed 316L, steel added with 10 wt% Mn was +0.8%, decreased by 4% compared with 316L. Radiation-induced Cr depletion at GB of 316L+10%Mn was smaller than that of 316L at 723 and 773 K. Decr ease of radiation-induced Cr depletion in 316LF+10%Mn is thought to be derived mainly from the suppression of vacancy-Cr atom interaction.