| 摘要 |
<p>PURPOSE: Structural steel and a manufacturing method thereof are provided to ensure high strength, high ductility, and a low-temperature impact value by setting a finish rolling temperature to 950-1,050°C. CONSTITUTION: Structural steel comprises C of 0.09-0.11wt.%, Si of 0.25-0.35wt.%, Mn of 1.25-1.35wt.%, P of 0.03wt.% or less, S of 0.015wt.% or less, Ni of 0.05-0.15wt.%, Cr of 0.15wt.% or less, Cu of 0.1-0.2wt.%, V of 0.18-0.22wt.%, Al of 0.01-0.02wt.%, Nb of 0.015-0.025wt.%, N 0.012-0.014wt.%, and Fe of the remaining amount. The structural steel has a yield strength of 500MPa or greater, an elongation ratio of 30% or greater, and an impact value at -5°C of 100J or greater.</p> |
