WELDING METHOD FOR STEAM TURBINE ROTOR

摘要

PROBLEM TO BE SOLVED: To provide a welding method for a steam turbine rotor, which is made highly reliable against a breakage by making a turbine rotor welding zone into a high quality.SOLUTION: A steam turbine rotor welding method is characterized in that a butt weld bevel has a dimensional ratio of a bevel portion R (A×a: A: 3-4) and a root width W (B×a: B: 0.5-1.5), when the bevel of the but weld has a spigot structure having a total root thickness of 2a, and in that a welding torch is set within the range of the root width W and performs a back wave welding. It is preferred that the back wave welding is performed by adjusting an execution condition while monitoring a melting section.