摘要:
采用金相显微镜和电镜研究了铝锌合金镀层钢板在不同温度条件下使用的镀层微观结构。结果表明:在300450℃的温度范围内长时间使用,镀层表面颜色虽没有变化,但随温度的提高枝晶裂纹逐渐扩展,扩散生成的Al-Si-Fe合金层逐渐由断续分布到连续分布,厚度增加,以致镀层与钢板基体开裂、剥落,耐蚀性能降低。500℃时,镀层很快全部合金化和氧化变色,镀层鼓泡,完全丧失耐蚀性能。
Abstract:
The change of plating microstructure was investigated by microscope and SEM,when the Galvalume sheet steel was tested in diverse high temperatures.It was showed the color of surface didn't change when temperature was in 300~450℃,but the Galvalume branching crystal cracks expanded larger and larger,as the temperature was higher.The Al-Si-Fe alloy stratum was formed and it's distribution developed from intermittence to continuum,it's thickness was increasing,So that plating cracking and desquamating with base sheet steel,the corrosion resistance decreased.The plating was all alloyed and oxide to change color quickly when temperature was in 500,it complete lost corrosion resistance in the end.
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