含稀土La的热浸镀AI-Zn合金层的显微组织和耐蚀性分析

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中图分类号：TG174.44

文献标识码：A 文章编号：1672-3791（2026）02-0114-04

Analysis of Microstructure and Corrosion Resistance of Hot-Dip Al-Zn AlloyLayerContaining Rare Earth La

YAN Hong

Kunming Metallurgical Research Institute Co.Ltd.，Kunming，Yunnan Province， 65Oo31 China Abstract： The microstructure and corrosion resistance of hot-dip Al-Zn alloy layer containing rare earth La were analyzed.The results showed that the hot dip alloy layer was mainly composed of an outer surface coating，an inner transition layer，andasteelsubstrate.Theouter plating layerwasdense and relativelyuniform，while the inner transition layer provided metalurgical bonding between the coating and the steel substrate.The surface of the coating hasa dendritic structure，consisting of Al rich dendrites and Al -Zn eutectoid phases between dendrites. The Al rich dendrites form the mainbodyof the surface，followed byAl-Zn eutectoid phases filled between dendrites.The corrosion rateofhot dip Al-Zn alloycontaining rare earth La is not only lower than that of Q235 steesubstrate，but also lower than that of hot dip Al-Zn alloy.In addition，coating defects were also discovered.All of these have a significant impact on improving the corrosion resistance of thecoating，enhancing thequalityof the coating，and understanding the plating process.

Keywords：Hot-dip coating of Al-Zn alloy;Rare earth La;Microstructure; Corrosion resistance;Coating defects热浸镀 Al-Zn 合金层作为一种表面处理层，不但能够使钢表面具有银白色的光泽和良好的耐蚀性[1]，而且可以保证钢的强度和韧性，尤其是 Al-Zn 合金镀层在较高温度下长期使用，具有较好的抗腐蚀能力，因此，热浸镀 Al-Zn 合金是钢的有效防护层2，在国防建筑、冶金、机械、石油化工、汽车、家电、桥梁等行业得到广泛的应用[3-4]。（剩余3307字）