The Super304H austenite stainless steel (0. 10C-18Cr-9Ni-3Cu-0. 4Nb- 0. 08N) is one of first selected materials for superheater and reheater tubes of ultra-supercritical unit. As the steel has higher carbon content and its service temperature ( ~ 650 °C ) is the sensitizing temperature of M

23

C

6

precipitating along grain boundary

how to avoid the occurrence of intergranular corrosion is a main research topic for Super304H steel. The research progress for intergranular corrosion susceptibility of Super304H steel at home and abroad is summarized in this article including intergranular corrosion mechanism

effect of alloy elements in steel especially Nb/C

double solid-solution treatment

stabilizing treatment

welding process and 600 ~ 700 ℃ high temperature aging on intergranular corrosion of this steel

and characterization methods for sensitiveness of i

ntergranular corrosion of Super304H steel. The research and development of Super304H steel is prospected.