| 摘要 |
<p>PURPOSE: A hot-rolled steel sheet with excellent workability and a manufacturing method thereof are provided to obtain the painting efficiency of a steel sheet and to suppress treatment defects such as fluting. CONSTITUTION: A hot-rolled steel sheet with excellent workability includes the following steps of: surface-treating the hot-rolled steel sheet in the width direction of the hot-rolled steel sheet to make a transformed ferrite structure occupy 3-10% of the surface; and shot-blasting a shot ball of 0.10-0.40 mm at a speed of 40-65 m/sec. C The steel sheet comprises 0.001-0.005 wt% of C, 0.05-0.3 wt% of Mn, 0.001-0.020 wt% of P, 0.02 wt% or less of S (except for 0), 0.01-0.07 wt% of Al, 0.001-0.004 wt% of N, 0.0005-0.002 wt% of B, 0.01-0.05 wt% of Co, 0.01-0.05 wt% of V, and the rest of Fe and unavoidable impurities. [Reference numerals] (AA) Evaluation value (fluting index & processability); (BB) Fluting index; (CC) Processability; (DD) Illumination index ratio (Rmax/Ra)</p> |
