工业污染区输电铁塔构件的大气腐蚀与防护

Atmospheric corrosion and protection of power transmission steel tower components in industrial pollution area

文章针对工业污染区服役20 a的高压输电铁塔构件,开展大气腐蚀与防护状况研究,揭示腐蚀机理。结果表明,工业污染区输电铁塔构件的大气腐蚀是一个电化学腐蚀过程,即使在同一角钢构件上,也存在腐蚀程度不同的区域。严重腐蚀区域镀锌层完全消失,腐蚀层开裂、碎化,失去对钢基体的保护。在污垢层未清除干净的钢构件表面涂覆铝防腐层,形成结瘤区域,雨水携带大气中的粉尘进入铝防腐层与镀锌钢之间的间隙中,加剧镀锌层与钢基体的腐蚀。相比而言,表面平整区域的铝防腐层和镀锌层完好,钢基体无腐蚀。处于工业污染区的输电铁塔构件表面镀锌层的防护有限,在严格遵守科学的操作规范时,表面涂装是十分有效的补充防护措施。

Research on atmospheric corrosion and protection status of the power transmission steel tower components served in an industrial pollution area for 20 years as well as corrosion mechanism was carried out.The results show that atmospheric corrosion of the power transmission steel tower components served in an industrial pollution area follows an electrochemical corrosion mechanism.Even for the same angle steel component,different areas of different corrosion degrees exist.As for the severe corrosion area,the hot-dip galvanized coating disappears completely.The corrosion layer is cracked and fragmented,losing protection for the steel matrix.The nodulation area is formed by plating the Al anti-corrosive paint on the angle steel component where the dust layer has not been cleaned up.Rain and dust in the air penetrate into the gap between the Al anti-corrosive layer and the galvanized steel,resulting in severe corrosion of the galvanized coating and the steel matrix.Contrarily,the Al anti-corrosion layer and the galvanized coating of the flat surface area are intact,and thus no corrosion of the steel matrix takes place.Protection of the galvanized coating is insufficient for the power transmission steel tower components in industrial pollution area,and surface painting is confirmed to be a very effective supplementary protective measure.However,it must be executed in a scientific and normative way.