| 摘要 |
<p>PURPOSE: A high strength submerged arc welded metal having excellent low temperature toughness is provided to secure high strength property, excellent low temperature impact toughness, and a low temperature CTOD(Crack Tip Opening Displacement) performance. CONSTITUTION: A high strength submerged arc welded metal having excellent low temperature toughness is composed of 0.05 to 0.1wt.% of C, 0.2 to 0.4wt.% of Si, 1.2 to 2.0wt.% of Mn, 0.023 to 0.03wt.% of Cr, 0.01 to 0.02wt.% of Ti, 0.01 to 0.2wt.% of Ni, less than 0.01wt.% of Mo, 0.004 to 0.006wt.% of B, 0.05wt.% of Nb, less than 0.01wt.% of V, 0.004 to 0.01wt.% of N, less than 0.02wt.% of P, less than 0.02wt.% of S, 0.03 to 0.05wt.% of O, 0.001 to 0.005wt.% of Al, 0.1 to 0.2wt.% of Cu, 0.001 to 0.02wt.% of one or more of Zr and Mg, one of 0.0005 to 0.01wt.% of Y or 0.0005 to 0.01wt.% of REM, and residual Fe and inevitable impurities.</p> |
