To reduce the residual stress in the whole surface of a welded metal by forming the welded metal at a specific range of a transformation starting temp. from the austenite to the martensite and executing a TIG remelt-run welding onto the surface of a last layer.
The welded metal layer having 150-300°C the transformation starting temp. from the austenite to the martensite, is formed and the TIG remelt-run welding is executed onto the surface of the last layer. A welding wire which can form the welded metal having such a characteristic, is necessary to pay very careful attention, and the welding wire having the parameter Pa defined by wt.% in each component of C, Ni, Cr and Mo with Pa=C+Ni/12+ Cγ/24+Mo/19 in the range of 0.95-1.30, is used. For example, the welding wire is contained by wt.% of 0.01-0.2 C, 0.1-0.5 Si, 0.01-1.5 Mn, ≤0.03 P, ≤0.02 S, 8-12 Ni and one or more kinds of 0.01-0.4 each of Ti and Nb, 0.3-1.0 V and the balance iron.
OKITA SHIGERU
FUJI MASAO
SAITO NAOKI
KOBAYASHI JUNICHI
CHIBA TOSHIHIKO
