Abstract
Along with the expansion of a recent power demand, the production of the steam turbine blades has increased, and a lot of forged materials of 12Cr steel, the ferritic heat-resisting steels have become widely used for this usage. However, although this material seems an excellent one as the heat-resisting steels, it necessitates correcting the deformation after machining, and, thus, lowers productivity. Therefore, we started a basic experimental research, and through a series of tests, we could find that 12Cr steel is a sticky material, that the residual stresses after machining concentrate on the surface neighborhood, and that this influences the deformation of blades.
