| 摘要 |
PURPOSE: A method for manufacturing a steel wire rod for cold forging is provided, which can conduct rapid spheroidizing annealing at low temperature. CONSTITUTION: The method includes the steps of reheating a steel billet comprising C 0.20 to 0.60 wt.%, Si 0.1 to 0.7 wt.%, Mn 0.3 to 1.5 wt.%, 0.03 wt.% or less of P, 0.03 wt.% or less of S, 0.10 wt.% or less of Al, a balance of Fe and incidental impurities; hot rolling the steel billet, wherein the finish hot rolling temperature is regulated below 700°C and total reduction ratio in finish hot rolling is regulated greater than 20 %; cooling the hot rolled steel wire rod to the temperature range of 500 to 400°C at a cooling rate of less than 10°C/sec; and cooling the steel wire rod to room temperature in air.
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