The abnormal segregation behavior of solutes under tensile stress and its effect on carbide reactions in 2.25Cr–1.5W heat-resistant steels

The phosphorus segregation concentration at grain boundary/carbide interfaces of 2.25Cr–1.5W heat-resistant steels under tensile stress shows a broad convex profile in a log time versus segregation concentration plot. The decrease in phosphorus segregation concentration after the maximum in the convex profile is due to the formation of new equilibrium MC carbides on the surface of the pre-formed M23C6 carbides and its partitioning effect of the phosphorus segregated at the M23C6 carbide interface to the interface of the new MC carbides.