| 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
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