HOT-ROLLED STEEL SHEET MANUFACTURING METHOD, CAPABLE OF PREVENTING THE DEGRADATION OF PIPE-MILLING PRODUCTIVITY AND THE SHAPE FAILURE OF A REELED COIL BY PREVENTING THE DISTORTION OF THE COIL

摘要

PURPOSE: A hot-rolled steel sheet manufacturing method is provided to obtain favorable welding using a slab including a low C.E(Carbon Equivalent).;CONSTITUTION: A hot-rolled steel sheet manufacturing method is as follows. A slab plate comprises 0.19-0.27 wt% of C, 0.50 wt% or less of Si, 1.00-1.40 wt% of Mn, 0.020 wt% or less of P, 0.010 wt% or less of S, 0.010-0.050 wt% or less of Al, 0.010-0.050 wt% or less of Ti, 0.10-0.40 wt% or less of Cr, 0.0080 wt% or less of N, 0.0010-0.0050 wt% of B, and 0.43-0.50 wt% of C.E. A slab plate is hot-rolled(S100). The hot-rolled plate is cooled(S102). The plate is reeled into a coil shape at a CT(Coiling Temperature) of 520-560°C.;COPYRIGHT KIPO 2013;[Reference numerals] (AA) Start; (BB) End; (S100) Hot rolling; (S101) Reheating; (S102) Cooling; (S200) Winding(520-560°C)