7B04铝合金海洋性大气腐蚀研究

通过在青岛和海南开展的7B04铝合金户外大气暴露试验,利用失重分析、形貌观察、断面分析和电化学交流阻抗谱等研究了7B04铝合金在海洋性大气环境中的腐蚀动力学规律和腐蚀特征。结果表明,在青岛和海南等海洋性大气环境中,7B04铝合金腐蚀初期以点蚀形式萌生,随后向均匀腐蚀发展;腐蚀过程均经历了腐蚀速率由高到低的过程,且腐蚀失重与时间的关系均可用幂函数显著回归;电化学阻抗谱分析表明当腐蚀产物足够厚时,7B04铝合金海洋性大气腐蚀的电化学过程由侵蚀性离子的扩散步骤来控制。

Study on Corrosion of 7B04 Aluminum Alloy in Marine Atmosphere

Outdoor exposure tests of 7B04 aluminum alloy were carried out in Qingdao and Hainan.Corrosion samples were investigated by mass loss,SEM,EIS methods.The results showed that at the initial stage pitting corrosion emerges on the surface of 7B04 alloy in Qingdao and Hainan,and transform into general corrosion later.Both the corrosion rates in Qingdao and Hainan experience a process from high to low,and the relationship of weight loss and time can be regressed by power function.The EIS revealed that when corrosion product is adequately thick,the electrode process of atmospheric corrosion in marine atmosphere is controlled by diffusion of corrosive ions from outer to the metal/oxide film interface.