Production mannered null mass of the steel which is superior in weather resistance and resistance paint

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a steel material preventing surface flaw and excellent in weatherability and coating-peeling resistance.;SOLUTION: This producing method is performed as the followings, with which to a slab composed by mass% of 0.001-0.15% C, ≤2.5% Si, 0.5-2.5% Mn, ≤0.03% P, ≤0.005% S, 0.05-1.0% Cu, 0.01-0.5% Ni, 0.01-3.0% Cr, 0.003-0.2% A, 0.001-0.1% N, 0.005% O, 0.03-0.20 Sn and the balance Fe with impurities, after heating the surface of the slab having ≤0.5 Ni/Cu to 1175-1325°C, a rolling of ≥70% of the total rolling reduction ratio, is completed in the temperature range of ≥900°C, and after completing the rolling at ≥700°C, if necessary, this steel material is cooled to ≤500°C at ≤30°C/s the average cooling rate.;COPYRIGHT: (C)2008,JPO&INPIT