WELD METAL FOR UNDER MATCHING HAVING EXCELLENT BRITTLE FRACTURE RESISTANCE GROWTH CHARACTERISTIC

摘要

PROBLEM TO BE SOLVED: To provide weld metal which has high strength and with which sufficient fracture toughness can be assured even if the hardness of the weld metal in a welded joint part is below≤210 in welding of a thick steel plate having a plate thickness exceeding 50 mm. SOLUTION: The weld metal for under matching having the excellent brittle fracture resistance growth characteristic is a metallic structure of≤210 in hardness (Hv) of the weld metal in the welded joint of a welded structure,≤8μm in the diameter of the equivalent circle in the crystal particle diameter of the weld metal,≤10% in the area rate of the island-shaped martensite of the weld metal and≤40% in the area rate of the ferrite of a length≥30μm and a width≥10μm. COPYRIGHT: (C)2006,JPO&NCIPI