| 摘要 |
<p>A high strength cold-rolled steel sheet having weatherability, formability, and at least 80 kgf/mm^2 of tensile strength is provided, and a method for manufacturing the same is provided. A high strength cold-rolled steel sheet with excellent weatherability and formability has a composition comprising, by weight percent, 0.10 to 0.20% of carbon(C), 0.05 to 0.25% of silicon(Si), 1.0 to 2.5% of manganese(Mn), 0.02% or less of phosphorous(P), 0.01% or less of sulfur(S), 0.02 to 0.07% of aluminum(Al), 0.02 to 0.08% of niobium(Nb), 0.05 to 0.30% of nickel(Ni), 0.1 to 0.5% of copper(Cu), 0.8 to 1.5% of chromium(Cr), and 0.01 to 0.10% of cobalt(Co) with the balance of Fe and other inevitable impurities, and is comprised of 10 to 30% of a low temperature transformed structure, and the balance of ferrite. The low temperature transformed structure comprises at least one of martensite and bainite.</p> |
