Abstract
In this study, creep tests have been conducted on a P91 to identify creep rupture life property of the weld joints, and creep damage process in heat affect zone (HAZ) has been clarified by producing creep damaged materials. As results, it was found that creep rupture time of the weld joints reduced to about 1/5 of the base metal and creep voids have already initiated at 20% of the creep life in the HAZ. Size and number of voids in the HAZ increased with increasing creep damage. Creep rupture time of the weld joint can be predicted by creep strain rate in the HAZ and limited creep strain defined in this study. It was confirmed that quantitative void growth behavior could be predicted by the void growth simulation method.
