PURPOSE: To perform welding without causing the embrittlement of a heat- affected zone with high efficiency by carrying out the weld pass for melting the base metal surface of the heat-affected zone by a TIG arc after piling up to a final layer.
CONSTITUTION: By weight, 16-21% Cr and 0.75-3.5% Mo are incorporated in the high purity ferritic stainless steel thick plate of base metal 1. In welding these, weld metals 2 are piled up to the final layer by multilayer sequence shielded metal arc welding. Afterward, the weld pass for melting the base metal 1 surface of the heat-affected zone 3 by the TIG arc is carried out to form beads 4 and 5 by the TIG arc. At least the weld pass of final layer between a first layer and the final layer is carried out by TIG welding, the weld pass of the other layer is carried out by shielding metal arc welding. Consequently, the welding cost and the quality can be compatible with each other.
TANAKA TAKASHI
UMENO MASANORI
