Effect of Ce addition on the precipitation of deleterious phases and the associated intergranular corrosion resistance of 27Cr-7Ni hyper duplex stainless steels

The addition of Ce to a base alloy reduces the total size of the deleterious phases. In particular, Ce addition to a base alloy significantly decreases the amount of sigma phase precipitated, while slightly facilitating the precipitation of chromium nitride and the chi phase. During the initial stage of aging, the preferential precipitation of chromium nitride and the chi phase seems to be closely associated with the retardation of the precipitation of the sigma phase. The addition of Ce to a base alloy retards the decrease in the intergranular corrosion resistance of the alloy.