Investigation of Microstructure Performance in the HAZ of the High-purity OCr18Mo2 Ferrite Stainless Steel

摘要

Microstructure performance in the heat-affected zone (HAZ) of OCr18Mo2 ferrite stainless steel were studied by means of scanning electron microscopy (SEM), X-ray diffractometer and electron probe microanalysis (EPMA). Trends in grain coarsening, precipitation and fracture morphology in the HAZ were analysed after welding and reheating. Experimental results indicated that the coarsening of grain and spot-shape precipitation were the main reasons which resulted in the em-brittlement of the HAZ. Precipitations (including Cr_2N, TiN and TiC) in the HAZ promoted the brittle crack to be produced and developed.