Method for manufacturing a turbine rotor

摘要

An inspection method for a welded joint formed between a pair of base metals (10, 20) with a groove part (12, 22) and an abutment face (14, 24) being formed on a joint surface Wc between the pair of base metals. The method includes the steps of: forming a recessed groove (32) opening to a surface of the base metals in advance at one end of the abutment face; irradiating the joint surface Wc with an X-ray generator (34) placed on a groove part formation side (an exterior space O side) toward the joint surface Wc after at least one pass P1 of build-up welding is performed on the groove parts (12, 22); and determining the presence or absence of incomplete penetration in the welded joint part W based on an image formed on a photosensitive film (42) by radiation penetrating the joint surface Wc.

主权项

1. A method for manufacturing a turbine rotor, the method comprising the steps of:
forming a recessed groove on at least one of a first disk and a second disk adapted to a turbine rotor, each of the first disk and the second disk having a body supportable for a rotor blade and a circular part protruding from the body toward an axial direction, each of the circular parts of the first and second disks having a joint surface at a tip end of the circular part in the axial direction, the joint surface having an abutment face and a groove part, the joint surfaces of the first disk and the second disk being capable of contacting each other, the groove parts of the first disk and the second disk being capable of forming an outer circumferential groove outside of the abutment faces in a radial direction, the recessed groove being formed at a tip end side and an inner circumferential side on at least one of the first disk and the second disk so as to extend along a circumferential direction of the circular part; first-layer welding the abutment faces to each other through the outer circumferential groove so as to form a penetration part; imaging by x-ray radiation from outside of the penetration part in the radial direction of the circular part so as to form an image on a photosensive film by x-ray radiation penetrating the penetration part after the first-layer welding step; determining the presence or absence of incomplete penetration in the penetration part based on the image obtained in the step of imaging; second-layer welding the groove parts to each other around the penetration part when an absence of incomplete penetration is determined in the determining step; and repairing the penetration part when the presence of incomplete penetration is determined in the determining step.