In order to determine the suitable manufacturing condition of 12%Cr alloy steel casing castings for advanced steam turbines, which improve efficiency for fossil fuel power plant by increasing steam condition, the research into chemistry, heat treatment and welding was carried out, and a partial model casting manufactured by this steel was evaluated.
The laboratory test results indicated that the elevated temperature tensile strength and the room-temperature toughness were directly related to the room-temperature tensile strength. The stress rupture strength was found to be proportional to the tensile strength as well as the tendency toward increasing number of precipitates. The weldability of 12%Cr cast steel was likely to be the same as that of ordinary 1%CrMoV cast steels.
On the base of laboratory studies and the evaluation of a partial model casing, 12%Cr alloy steel casing casting were successfully manufactured offering the integrity and the excellent creep rupture strength.
