| 摘要 |
<p>A steel sheet for galvanizing which has a tensile strength of 28 to 50 kg/mm^2, superior formability, superior secondary working embrittlement resistance, superior fatigue strength of welding parts and superior surface quality, and a method for manufacturing the same are provided. A method for manufacturing a steel sheet for galvanizing with superior formability comprises: reheating a steel slab having a composition comprising, by weight percent, 0.010% or less of C, 0.1% or less of Si, 0.06 to 1.5% of Mn, 0.15% or less of P, 0.020% or less of S, 0.10 to 0.40% of soluble Al, 0.010% or less of N, 0.003 to 0.010% of Ti, 0.003 to 0.040% of Nb, 0.0002 to 0.0020% of B and 0.05% or less of Mo, 0.005 to 0.05% of Sb or/and 0.005 to 0.05% of Sn with the balance of Fe and other inevitable impurities, wherein the sum of Sb and Sn is 0.005 to 0.1% when Sn and Sb are added to the composition; hot finish rolling the reheated steel slab in an austenite single phase region to obtain a hot rolled steel sheet; coiling the hot rolled steel sheet; cold rolling the hot rolled steel sheet coil; and continuously annealing the cold rolled steel sheet coil in a temperature range of 700 deg.C or more.</p> |
