| 摘要 |
PURPOSE: A method of manufacturing high elastic wire rods for spring is provided, which is capable of producing high quality elastic wire rods with minimized material quality deviation and uniform microstructure. CONSTITUTION: In a method of manufacturing high elastic wire rods for spring that includes step of (a) continuous casting a molten steel comprising C 0.6 to 0.7 wt.%, Si 0.10 to 0.35 wt.%, Mn 0.90 to 1.10 wt.%, 0.020 wt.% or less of P, 0.020 wt.% or less of S, sol-Al 0.02 to 0.03 wt.%, 50 ppm or less of N, a balance of Fe and incidental impurities; (b) rolling the obtained bloom into billet; (c) heating the billet in the temperature range of 950 to 1100°C for 90 to 200 minutes for wire rod rolling; and (d) coiling the wire rod in the temperature range of 780 to 880°C followed by air cooling, the method is characterized in that above continuous casting is conducted under conditions that the degree of superheat of the molten steel is controlled to be less than 15°C and the reduction ratio is controlled within the range of 0.2 to 1.0%; and air cooling is conducted in such a state that the damper degree of air blower is adjusted to between 10 to 13 degrees so that average cooling rate is controlled to be less than 15°C/sec.
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