爆破引线用镀锌钢丝色差成因分析

Cause analysis of color difference of zinc-electroplated steel wires used as explosive fuses

针对某批次爆破引线用镀锌超低碳钢丝出现色差缺陷的问题,采用光学显微镜(OM)、扫描电子显微镜(SEM)、激光扫描共聚焦显微镜(LSCM)以及能谱仪(EDS)对比分析了正常试样和有色差试样的微观结构、表面粗糙度与元素组成,得出镀锌层出现色差的原因是镀锌前钢丝基材表面的氧化铁皮未除净和机械擦伤。通过减少热轧方坯的驻炉时间,提高除鳞水压力,适当增加工作锥角度,减小定径带长度等措施可显著减少镀锌钢丝的色差缺陷。

Aiming at solving the problem of color difference of zinc-electroplated ultra-low-carbon steel wires used as explosive fuses, the microstructure, surface roughness and elemental composition of normal samples and the ones with color difference defect were analyzed by optical microscopy （OM）, scanning electron microscopy （SEM）, laser scanning confocal microscopy （LSCM）, and energy-dispersive spectrometry （EDS）. It is shown that the color difference of electroplated zinc coating is caused by the residual oxide scales on the surface of steel wire prior to zinc electroplating and by mechanical scratching. Such defect can be significantly reduced by reducing the heating time of hot rolled billet in furnace, increasing the pressure of descaling water, enlarging the angle of working cone properly, and decreasing the length of calibrating strap.