Local creep evaluation of P92 steel weldment by small punch creep test

The aim of this research is to evaluate the local creep damage of various microstructures such as coarse grained heat affected zone (CGHAZ), fine grained heat affected zone (FGHAZ), intercritical heat affected zone (ICHAZ) known as Type IV region, weld metal, and base metal of P92(9Cr-2W) steel weldment by small punch (SP) creep test at 600°C. Also, to determine the weakest local part of the weldment, the effect of microstructures on creep rupture behavior in the weldment of P92 steel was studied. From the experimental results, the FGHAZ and Type IV region turned out to be very weak local parts of P92 weldment. Especially, the TYPE IV region showed the greatest displacement rate and had the shortest rupture life with many creep cavities widely spreaded in most of the region.