热浸镀铝钢的合金层抗高温氧化机理

Mechanism of High Temperature Oxidation Prevention of Alloy Layer on HotDip Aluminizing Steel

研究了热浸镀纯铝和铝硅合金的钢板在５００～１１００℃，５０ｈ氧化试验期间抗高温氧化行为．借助电子探针显微分析仪和Ｘ射线衍射仪研究了合金层的组织结构．结果表明：镀铝钢的氧化动力学曲线符合抛物线规律；纯铝镀层的抗高温氧化性优于铝硅合金镀层；后者在高温氧化过程中形成Ｆｅ３Ｓｉ隔层相，降低了镀铝钢的抗高温氧化性．

The high temperature antioxidation behavior of hotdipping Al and AlSi steel sheets is investigated in air over the temperature range from 500℃ to 1100℃ for up to 50 hours. Microstructures are examined by means of electronprobe microscope and Xray diffractometer. The results show that the oxidation kinetic curves of the aluminizing steels obey parabolic law and the oxidation resistance of Alcoated steel is significantly superior to that of AlSicoated steel. Because a Fe3Si barrier layer is formed in the AlSi alloy diffusion layer during oxidation,the high temperature oxidation resistance of hotdipping AlSi alloy steel sheet is reduced.