Welding of dissimilar materials

In fossil fuel fired power plants, appropriate materials are required which correspond to the different temperature and oxidizing conditions in the boiler and in the super-heater sections. Pipe steels with (T/P22; T/P23; T/P24) must be welded with 9–12%Cr steels (T/P91; T/P92). In this area, the choice of the appropriate welding filler material is decisive for the quality of the connection. This report highlights the possibilities for achieving optimal qualities in different dissimilar metal welds under conditions of reduced carbon diffusion.