钢绞线用SWRH72BCr盘条质量改进

Quality improvement of SWRH72BCr wire rod for steel strand

对影响钢绞线用SWRH72BCr盘条合格率的关键因素进行分析,认为连铸坯的横向裂纹是造成盘条结疤缺陷的主要原因。盘条添加的V元素在增加淬透性的同时使珠光体与贝氏体相变区发生分离,增加了小规格盘条的控冷难度,斯太尔摩风冷线冷却不均匀是盘条强度不合格的直接原因。通过改善连铸工艺,调整斯太尔摩线佳灵装置与风机风量,将佳灵装置的角度由30°调整至50°,对轧制工艺优化改进后盘条平均抗拉强度提高约20 MPa,抗拉强度最大波动80 MPa,产品综合合格率由94.0%提高到98.99%。

To analyze key factors affecting qualification rate of SWRH72BCr wire rod for steel strands,it is believed that transverse cracks in continuous casting billets are main cause of wire rod scar defects.The addition of V element to wire rod not only increases hardenability but also separates pearlite and bainite transformation zones,increasing difficulty of control cooling for small-sized wire rods.The uneven cooling of Stelmor cooling line is direct reason for wire rod unqualified strength.By improving continuous casting process,adjusting Jialing device angle from 30° to 50° and fan air volume on Stelmor line,optimizing rolling process,wire rod average tensile strength is increased about 20 MPa,with maximum fluctuation of 80 MPa in tensile strength.The comprehensive product qualification rate is increased from 94.0% to 98.99%.