大桥斜拉索制造关键技术研究

Study on key technology of bridge stay cable manufacturing

大桥用镀锌钢丝必须同时满足扭转≥8次,松弛率≤2.5%,抗拉强度≥1 670 MPa。介绍大桥斜拉索用镀锌钢丝和斜拉索制作工艺。选用宝钢B82MnQL盘条生产7.0 mm镀锌钢丝,锌层面质量≥300 g/m2。镀锌钢丝生产过程中应提高钢丝表面质量、直线度及镦头性能。降低斜拉索索体扭转的方法:改进绞制与挤塑工序牵引方式;改进绞制弯道以保持斜拉索绞制节距稳定;改进索体绕包张力。对新型斜拉索密封体系进行研发。斜拉索疲劳性能改进措施:提高镀锌钢丝表面质量均匀性、直线性和直径精度。生产的镀锌钢丝斜拉索经检验和使用,能够满足用户的特殊要求。

Galvanized steel wire for bridge must meet torsion value no less than 8 times, relaxation ratio no more than 2.5%, tensile strength no less than 1 670 MPa. The production process of galvanized steel wire for bridge stay cable and stay cable was introduced. Baosteel B82MnQL wire rod was chose to produce diameter 7.0 mm galvanized steel wire, zinc layer mass fraction is no less than 300 g,/m^2. In production process of galvanized steel wire, steal wire surface quality, straightness and heading performance were improved. The method of decreasing torsion of stay cable is as follows： to improve pulling method of stranding and extrusion process, to improve stranding corner to keep stay cable stranding pitch stability, to improve cable lapping tension. The new type stay cable sealing system is researched. The improvement measures of stay cable fatigue properties are as follows ： to improve galvanized steel wire surface quality uniformity, straightness and diameter accuracy. The galvanized steel wire stay cable can meet special requirements of customers after it is tested and used.