Abstract
In order to evaluate the effect of specimen size and the condition of hydrogen charge into the specimen on the threshold stress intensity factor K_<IH> for hydrogen assisted cracking, HLF (holding load fractography) method was applied to 2.25Cr-1Mo steel. The FRASTA (fracture surface topography analysis) technique was also used to discuss the relation between the 3-D configuration of fracture surface and the HAC characteristics.
