Abstract
Creep damage was imposed on the austenitic stainless steel SUS304HTB for boiler tube use under the conditions of 650℃-130MPa and 700℃-75MPa. EBSD(Electron BackScatter Diffraction pattern) observation was conducted on the creep damaged samples using KAM(Kernel Average Misorientation) maps and GROD(Grain Reference Orientation Deviation) maps. Area averaged KAM and GROD values; KAM_<ave> and GROD_<ave> were used as the comparative parameter to time fraction and creep strain. While KAM_<ave> showed apparent dependence on EBSD pixel step size (i.e. observation magnification), GROD_<ave> did not show such dependence. KAM strain pa rameter, M_<εKAM> proposed here showed more unified and monotonic correlation with creep strain than KAM_<ave> GROD_<ave> showed much more unified and linear correlation with strain except for final rupture stage. Using GROD_<ave> creep void growth process can be quantitatively evaluated.
