自润滑钝化膜对热镀铝锌板冲压成型性能的影响

Effect of self-lubricating passive film on stamping formability of hot-dip aluminum–zinc coated steel plate

考察了不同钝化液处理的热镀铝锌板冲压后的外观及摩擦性能。用扫描电镜和能谱仪分析了钢板的表面形貌和元素成分,探索了自润滑钝化膜改善钢板冲压性能的机理。提高钝化膜的自润滑性可以显著改善钢板的冲压成型性能。经过无铬自润滑型钝化液处理的热镀铝锌板在直接冲压成型后表面的皮膜得以完整保留,无明显划伤、犁痕、发黑等不良现象,且经过120 h中性盐雾试验后的锈蚀面积小于5%,能满足家电行业的要求。

The appearance after stamping and friction properties of hot-dip Al–Zn coated steel plates treated with different passivation solutions were studied. The surface morphologies and elemental composition of the steel plates were analyzed by scanning electron microscope and energy-dispersive spectroscopy. The mechanism that makes the self-lubricating passive film improve the stamping formability of steel plate was studied. The improvement of self-lubrication of passive film can greatly improve the stamping formability of steel plate. The film formed on the surface of hot-dip Al–Zn coated steel plate by being treated with a chromium-free self-lubricating passivation solution is intact, and has no obvious scratch, furrow, and blackening defects after direct stamping, and its corroded area is less than 5% after neutral salt spray test for 120 h, meeting the requirements of home appliance industry.