Turbine rotor, manufacturing method thereof and steam turbine using turbine rotor

摘要

The present invention is a turbine rotor (20) which includes: a high temperature side rotor base material (21), and a low temperature side rotor base material (22). The high temperature side rotor base material (21) and the low temperature side rotor base material (22) respectively include concavities (26, 27) and grooves. The turbine rotor (20) has an enclosed space section formed by the concavity (26) of the high temperature side rotor base material (21) and the concavity (27) of the low temperature side rotor base material (22) being disposed opposingly, and a gap formed by the groove of the high temperature side rotor base material (21) and the groove of the low temperature side rotor base material (22) being disposed opposingly. The turbine rotor (20) contains a buildup welding section (23) formed between the high temperature side rotor base material (21) and the low temperature side rotor base material (22). The buildup welding section (23) has the same composition as that of the high temperature side rotor base material (21) or the low temperature side rotor base material (22), and has a penetration bead on the enclosed space section side, and the gap contains a weld metal filled therein. Thus, a stable penetration bead can be formed in a dissimilar material welded rotor (20) combining two kinds of alloy materials different in thermal property, and then generation of a non-welded portion of a butting section that becomes a start point of fracture can be suppressed.