Abstract: ［Objective］ To address the corrosion-induced failure of Q420NH weathering steelused in power grid towers during service，an epoxy anti-corrosion coating with both excellent corrosionresistance and corrosion-inhibition self-healing capability was developed to improve the long-termprotection of tower steel structures.［Methods］A composite filler loaded with corrosion inhibitor 5-amino-2-mercaptobenzimidazole（AMB） was prepared by a one-step method. Then，it was incorporated into an epoxy coating，and applied onto the surface of Q420NH steel to construct a composite anti-corrosion coating. The morphology and composition of the composite filler were characterized，and its corrosion inhibition effect，as well as the corrosion resistance and self-healingperformance of the coating，were evaluated through release experiments，corrosion morphologyobservation，and electrochemical tests.［Results］ The composite filler had a particle size about 100 nm，and the inhibitor loading was 17. 5%. When the addition amount of the composite filler was nomore than 2%，the corrosion resistance of the epoxy coating was effectively maintained，with the low-frequency impedance modulus remaining above 10¹⁰ Ω ·cm² after 60 days of immersion in saline solution. For the scratched coating containing 2% composite filler，the low-frequency impedance modulus remained higher than 10⁵ Ω ·cm² after 168 h of immersion，the corrosion products in the scratched region were significantly reduced，and the characteristic Raman peaks of AMB were detected.［Conclusion］ The incorporation of 2% composite filler can effectively enhance the protectiveperformance of the epoxy coating on Q420NH steel and endow the coating with excellent corrosion-inhibition self-healing capability.

Key words: weathering steel, corrosion inhibitor, anti-corrosion coating, self-healing, epoxy coatings

摘要： 【目的】针对电网杆塔用 Q420NH耐候钢在服役过程中的腐蚀失效问题，制备了一种兼具耐腐蚀性与缓蚀自修复性的环氧防腐涂层，以提升杆塔钢结构的长期防护能力。【方法】采用一步法制备了负载缓蚀剂 5-氨基-2-巯基苯并咪唑（AMB）的复合填料，将其添加到环氧涂料中，在 Q420NH钢表面构建复合防腐涂层。对复合填料的形貌和组成进行了表征，结合释放实验、腐蚀形貌观察和电化学测试，评价了复合填料的缓蚀作用以及涂层的耐腐蚀性与自修复性。【结果】复合填料的粒径约 100 nm，缓蚀剂负载率为 17. 5%。当复合填料的质量分数≤2%时，可有效保持环氧树脂涂层的耐腐蚀性，盐水浸泡 60 d后的低频阻抗模值>10¹⁰ Ω·cm²。添加 2%复合填料的划伤涂层浸泡 168 h后的低频阻抗模值>10⁵ Ω·cm²划伤区域腐蚀产物明显减少，并检测到缓蚀剂 AMB的拉曼特征峰。【结论】添加 2%的复合填料可有效提升环氧涂，层对 Q420NH钢的防护效果，并赋予涂层良好的缓蚀自修复能力。

关键词: 耐候钢, 缓蚀剂, 防腐涂层, 自修复, 环氧涂料

CLC Number: 

• TQ635. 2