A continuous casting method for eliminating dendrite band segregation near the surface of alloy spring steel wire rod

Abstract

The invention discloses a continuous casting method for eliminating dendrite strip segregation near the surface of an alloy spring steel wire rod. The method comprises the control of the superheat degree of molten steel in a continuous casting tundish, the control of the casting speed of a continuous casting slab, and the control of electromagnetic stirring in a crystallizer. , crystallizer water flow control and vibration parameter control process; the superheat of molten steel in the tundish is controlled at 15-25°C through the electromagnetic induction heating equipment of the tundish; 150~300A, frequency 1.5~2.5Hz; adopt hydraulic vibration, amplitude 2.3~2.7mm, vibration frequency 100~130cpm, liquid level fluctuation is controlled within ±2mm. The φ5.5-20mm alloy spring steel wire rod produced by the continuous casting method of the present invention has no near-surface dendrite band segregation through dendrite corrosion detection, and the surface layer metallographic structure is uniform after heat treatment, effectively preventing the dendrite band segregation caused by dendrite band segregation. Early fatigue fracture of the spring.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a continuous casting method for eliminating dendrite band segregation near the surface of an alloy spring steel wire rod. Background technique [0002] Alloy spring steel hot-rolled wire rod is mainly used to manufacture automobile suspension springs, clutch springs, valve springs and die springs, mainly including 55SiCr, 55SiCrV, 60Si2Mn and other grades. Spring steel hot-rolled wire rods must at least go through drawing, heat treatment, coiling and other processing processes before they can become final springs. If the wire rod has a certain degree of macrosegregation defects, it may cause the steel wire to break after drawing. The mechanical properties of the steel wire after heat treatment Unevenness, unstable dimensions of the rolled out spring, and even early fatigue fracture of the spring. [0003] Dendrite banded segregation of spring steel refers to the f...

AI Technical Summary

Problems solved by technology

This method is mainly used to solve the problem of product change caused by ingot shape segregation, and does not consider the problem of dendrite band segregation defects near the surface in the wire rod

[0005] Patent CN 108672666 A discloses a continuous casting method for improving the central segregation of round billet spring steel 60Si2CrVAT, and the tundish temperature, crystallizer water volume, secondary cooling zone water volume, electromagnetic stirring parameters, terminal electromagnetic stirring position, etc. of the round billet continuous casting process are disclosed. Control to reduce the central segregation of the continuous casting slab, reducing the plastic incompatibility problem caused by the central segregation, and also did not consider the problem of dendrite band segregation defects near the surface in the wire rod

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