热扩散温度对电镀锌C72D2钢丝镀层结构及性能的影响

Effect of Thermal Diffusion Temperature on Coating Structure and Properties of Electro-Galvanized C72D2Steel Wire

采用电镀工艺在C72D2钢丝表面镀锌,单位面积镀层质量为45g·m^(-2),然后在不同温度(450~550℃)下进行热扩散处理,采用湿式拉拔工艺将镀锌钢丝拉拔成单丝,研究了热扩散温度对镀层结构、单丝抗拉强度及单丝旋转弯曲疲劳性能的影响;通过与热浸镀锌钢丝和单丝的对比,优选出最佳的电镀锌热扩散工艺。结果表明:随着热扩散温度升高,电镀锌钢丝镀层中的锌铁合金相增多,且富铁相增多,富锌相减少,在520℃以上时生成Fe_(3)Zn_(10)脆性相,镀层出现裂纹;经480℃热扩散处理的电镀锌单丝与热浸镀锌单丝相比,抗拉强度较高,镀层损失较小,疲劳寿命相近,满足电梯曳引带钢丝绳用单丝的使用要求。

Electroplating process was used to galvanize the surface of C72D2steel wire,and the mass of the coating per unit area was 45g·m^(-2).The thermal diffusion treatment was carried out at different temperatures(450-550℃),and the galvanized steel wire was drawn into monofilament by wet drawing process.The effects of thermal diffusion temperature on the structure of the coating,the tensile strength and rotating bending fatigue performance of monofilament were studied.By comparing with hot dip galvanized steel wire and monofilament,the best electro-galvanized thermal diffusion process was optimized.The results show that with increasing thermal diffusion temperature,the Zn-Fe alloy phase in the electro-galvanized steel wire coating increased,and the Fe-rich phase increased,while the Zn-rich phase decreased.When the temperature was above 520℃,the Fe_(3)Zn_(10)brittle phase was formed,and cracks appeared in the coating.Compared with the hot dip galvanized monofilament,the electro-galvanized monofilament treated by thermal diffusion at 480℃had higher tensile strength,less coating loss,and similar fatigue life,which met the requirements for the use of monofilament for elevator traction belt wire ropes.