| 摘要 |
PURPOSE: A method for manufacturing wire rod is provided, which realizes high strength characteristics at application products as enabling cold punching without life time reduction of dies by controlling steel constituents and manufacturing conditions, thereby sufficiently lowering steel strength after spheroidizing heat treatment. CONSTITUTION: The method comprises the processes of reheating a steel slab comprising 0.15 to 0.25 wt.% of C, 0.10 to 0.60 wt.% of Si, 0.1 to 1.0 wt.% of Mn, 0.03 wt.% or less of P, 0.03 wt.% or less of S, 1.0 to 2.50 wt.% of Cr, 0.20 to 1.0 wt.% of Mo, 0.05 to 0.20 wt.% of V, 0.01 to 0.05 wt.% of Nb, 0.0050 to 0.0150 wt.% of N and a balance of Fe and other inevitable impurities to a temperature of 1,000 to 1,200 deg.C; hot rolling wire rod at a finishing rolling temperature being 1,000 deg.C or less; and cooling the hot rolled wire rod at a cooling rate of 0.1 to 10 deg.C/sec, wherein the steel slab comprises 1.5 to 2.5 wt.% of Cr.
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