Structural changes of 12Cr1MoVG steel during high-temperature creep

Abstract

Heat-resistant steels are key metal materials for high-temperature and high-pressure boilers of ultra-super critical (USC) power plants. A lot of steels have been designed for heat resistance purposes, among which 12Cr1MoVG steel is a good alternative but has not been studied intensively for its high-temperature creep properties. In the current work, the 12Cr1MoVG steel was subjected to long-term creep at different temperatures. The 20000 h creep rupture stress showed obvious decrease with increasing temperature in the data range. The structural changes of the 12Cr1MoVG steel during the high-temperature creep tests was investigated by analyzing the cavitation and metallographic structure before and after the creep tests. The results indicated that the structural changes had close relationships with the creep behavior and mechanical properties of the steel. This work gives insights into the high-temperature creep study of heat-resistant steels.