钢绞线质量的提升

QUALITY IMPROVEMENT OF STEEL STRAND

张宣科技低松弛预应力钢绞线在生产初期存在成品性能低、性能不稳定、尺寸超差、表面锈蚀等质量缺陷,本文对钢绞线综合性能以及外观质量的提升进行了研究。结果表明,以原料强度1180 MPa为界点,当二级强度原料投料占比最低为47.37%时,钢丝平均破断力为最高值39.03 kN,当二级强度原料投料占比最高为82.35%时,钢丝平均破断力为最低值38.55 kN,二级强度原料投料占比与半成品钢丝破断力基本呈负线性相关性;将模具工作芯材质改用硬质合金钨钢YG8,可解决模具在线使用寿命低的问题;捻股配丝时合理搭配边丝,控制中频炉温度范围处于365~375℃,每根钢丝的缩径处于0.02~0.04 mm的标准范围,可解决钢绞线尺寸较差的问题;控制酸洗有效反应时间在22.5~30 min,合理提高皂片单耗至0.36 kg/t,使用工业水,可避免表面锈蚀,提升酸洗磷化质量,保证磷化膜厚度为7.5~9.3 g/m^(2);外包装垫木改用带有固定刻槽75 mm×75 mm×750 mm的油松,提升了钢绞线外观质量。

In the early stage of production,there are some quality defects in the low-relaxation prestressed steel strand in Zhangxuan Technology,such as low performance,unstable performance,out-of-tolerance size,surface corrosion,etc.In this paper,the comprehensive properties of steel strand and the improvement of appearance quality are studied.The results show that the average breaking force of steel wire is 39.03 kN at the critical point of 1180 MPa when the proportion of the second-grade strength material is 47.37%,and when the proportion of the second-grade strength material is 82.35%,the average breaking force of steel wire is 38.55 kN at the critical point of 1180 MPa.And the ratio of secondary strength raw materials to the breaking force of semi-finished steel wire is basically negative Linear independence.Changing the material of die working core to carbide tungsten steel YG8 can solve the problem of low on-line service life of die.The problem of bad strand size can be solved by reasonable matching of side wire,controlling the temperature range of intermediate frequency furnace at 365~375℃and reducing diameter of each steel wire at the standard range of 0.02~0.04 mm.Controlling the effective reaction time of pickling in 22.5~30 min,reasonably increasing the unit consumption of soap to 0.36 kg/t,using industrial water can avoid the surface rusting,improve the quality of pickling phosphating,and ensure the thickness of phosphating film to be 7.5~9.3 g/m^(2).The outer packing shim was replaced by Pinus tabulaeformis with fixed grooves of 75 mm×75 mm×750 mm to improve the appearance quality of steel strand.