| 摘要 |
PROBLEM TO BE SOLVED: To provide a weld joint in which high toughness is ensured in each of a weld metal, a heat-affected zone and a bond part of a welded part with large heat input of a steel plate. SOLUTION: B is added in the steel plate so as not to adversely affect the toughness. B is sufficiently added in the weld metal part so as to suppress precipitation of a ferrite side plate generated from an austenitic grain boundary. B is added to the heat-affected zone so that the necessary minimum quantity of B to fix solid solution N generated by solid solution of TiN is ensured by the diffusion of B from the weld metal part. |
