| 摘要 |
<p>PURPOSE: A high-strength steel sheet for a line pipe and a manufacturing method thereof are provided to improve toughness by increasing the content of Mn and decreasing the content of C. CONSTITUTION: A manufacturing method for a high-strength steel sheet for a line pipe is as follows. A slab sheet is composed of 0.02-0.08wt.% of C, below 0.4wt.% of Si, 1.8-2.5wt.% of Mn, 0.1-0.5wt.% of Cr, 0.2-1.0wt.% of Ni, 0.2-1.0wt.% of Mo, below 0.030wt.% of Al, 0.2-1.0wt.% of Cu, 0.01-0.02wt.% of Ti, 0.005-0.05wt.% of Nb, 0.055-0.10wt% of V, 0.0002-0.005wt.% of B, below 0.0004wt.% of Ca, and the rest of Fe and inevitable impurities. The slab sheet is hot-rolled(S120). The hot-rolled slab sheet is cooled(S130).</p> |
