| 摘要 |
PURPOSE: A preparation method of a wire rod used in wire ropes, bead wires and springs is provided to control forming the martensite produced by the central segregation of Mn. CONSTITUTION: The preparation method of a wire rod to control forming the martensite of Mn segregation part comprises reheating billets composed of 0.4 to 1.0 wt.% of C, 0.1 to 1.0 wt.% of Mn, 0.1 to 1.5 wt.% of Si, not more than 0.03 wt.% of S, not more than 0.03 wt.% of P and the balance of Fe and the inevitable impurities and having Mn amount of the segregation band of not more than 1.3%, hot rolling the wire rod to austenite crystal grains having the size of not more than 15 micrometers, followed by cooling in a rate of 20 to 25 deg.C/sec to the temperature of 600 to 500 deg.C, and then cooling to the ambient temperature in a rate of not more than 10 deg.C/sec when the carbon amount is 0.4 to 0.6 wt.% or cooling to the ambient temperature in a rate of not more than 5 deg.C/sec when the carbon amount is 0.6 to 1.0 wt.%.
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