EFFECTS OF GRAIN-BOUNDARY MISORIENTATION ON THE SOLUTE SEGREGATION INAUSTENITIC STAINLESS-STEELS

The purpose of this study is to understand the effects of grain bounda ry misorientation on the solute segregation in austenitic stainless st eels irradiated by protons. Many studies have shown that, for the Gibb sian type of segregation, the grain boundaries possess an ordered stru cture and the degree of segregation depends on the grain boundary miso rientation. In contrast to the Gibbsian type of segregation, radiation induced segregation at grain boundaries is a nonequilibrium segregati on phenomena. The 304 and 316L specimens were chosen for this study an d irradiated by 5 MeV protons at a temperature of 450 degrees C. The C r/Ni-concentration profiles were measured by FEG/EDS and the grain bou ndary misorientation was determined by Kikuchi patterns. It seems from the preliminary results that the segregation to the grain boundary wo uld tend to happen at boundaries with higher Sigma value. (C) 1998 Els evier Science B.V. All rights reserved.