| 摘要 |
<p>Disclosed are a steel material and a manufacturing method thereof which can guarantee resistance to hydrogen induced cracking by strictly applying a steel manufacturing standard. The steel material according to the present invention is composed of 0.01-0.10 wt.% of C, 0.1-0.4 wt.% of Si, 1.3-1.6 wt.% of Mn, 0.1-0.4 wt.% of Cu, 0.2-0.4 wt.% of Ni, 0.001-0.003% of Ca, 0.1-0.3 wt.% of Cr, 0.01-0.04 wt.% of Nb, 0.05-0.15 wt.% of Mo, 0.006 wt.% or less of N, 2.0 ppm or less of Ni, and the rest of Fe and other inevitable impurities. The steel material has 550-750 MPa of tensile strength (TS), 450-600 MPa of yield point (YP), and 27% or more of elongation (EL). [Reference numerals] (AA) START;(BB) END;(S110) Steel manufacture;(S120) Continuous casting;(S130) Slab reheating;(S140) Hot-rolling;(S150) Cooling</p> |
