2024-T62铝合金涂层外场腐蚀环境下电化学性能研究

目的评估自然暴露条件下涂层的耐蚀性能。方法选取西沙热带海洋环境作为自然暴晒场,开展2024-T62铝合金涂层(N1和N2)在湿热暴露、紫外照射、盐雾等综合腐蚀环境下的外场暴晒试验,利用电化学测试方法对暴晒后涂层在3.5%Na Cl溶液中浸泡不同时间的耐蚀性能进行研究。结果铝合金涂层外场暴晒试验后,电化学阻抗值下降,综合腐蚀环境具有显明的加速作用。随着在3.5%Na Cl溶液的浸泡时间增加,C_(coat)-T值不断增大,Rcoat值不断减小。结论 N1铝合金涂层暴晒件电化学阻抗值较高,具有较强的耐蚀性能。

Electrochemical Property for 2024-T62 Aluminum Alloy Surface Protective Coating in the Presence of Outfield Corrosion

Objective To evaluate the corrosion resistance performance of the coating under the condition of natural exposure. Methods Field exposure experiments of 2024-T62 aluminum alloy coating (N1 and N2) under comprehensive corrosion conditions including wet and heat exposure, UV irradiation and salt spray were carried out, selecting the tropical marine environment in Xisha as the natural exposure field. Electrochemical methods were adopted to investigate the corrosion resistance of the exposed coatings after immersing in 3.5% NaCl for different time. Results The results showed that the electrochemical impedance of the coating after the field exposure decreased, indicating the significant accelerating effect of the comprehensive corrosion condition, Ccoat-T increased and Rcoat decreased continuously with the elongation of immersion time in 3.5% NaCl. Conclusion The electrochemical impedance of the exposed N1 coating was relatively high, implying its strong corrosion resistance.