Microstructure evolution of 12%Cr steels for tubes and pipes in power generation industry

The advanced operating conditions for steam power plants require materials with higher steam oxidation resistance and creep strength and 9 - 12 % Cr tempered martensitic steels are excellent candidates. The main strengthening mechanism in these materials is precipitate strengthening by MX particles; and the breakdown of creep strength could be associated with changes in the microstructure of the material. Microstructure analysis together with simulations in MatCalc software are excellent tools to evaluate the microstructures changes and to be able to know which changes in the microstructure are related with mechanical properties, like creep.