| 摘要 |
PROBLEM TO BE SOLVED: To provide high tensile steel in which impact value at -56°C is≥80 J in a HAZ (heat affected zone) and is≥50 J in a weld metal zone even if high heat input submerge arc welding of≥150 kJ/cm is performed, and to provide a weld metal. SOLUTION: The high tensile strength steel has a composition comprising≤0.07% C,≤0.30% Si, 1.0 to 2.0% Mn, 0.04 to 0.10% sol.Al, 0.0020 to 0.010% N, 0.005 to 0.020% Ti and 0.0005 to 0.005% B, and the balance Fe with inevitable impurities, and in which the value of ARM expressed by formula (1) is 40 to 80: ARM=197-1,457C-1,140sol.Al+11,850N-316(Pcm-C) (1). The weld metal has a composition comprising≤0.12% C,≤0.30% Si, 1.0 to 2.0% Mn, 0.01 to 0.05% total Al, 0.0020 to 0.010% N, 0.01 to 0.04% O, 0.005 to 0.020% Ti and 0.002 to 0.008% B, and in which the value of ARW expressed by formula (2) is≥50: ARW=145×B/N+142×f(Al/O)-140 (2). COPYRIGHT: (C)2005,JPO&NCIPI
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