Zn-5Al合金镀层表面三价铬-铈盐复合钝化膜的制备与性能

刘志宏¹, 李阳², 梁国威², 孙国庆³, 赖德林²

1. 天津友发钢管集团股份有限公司
2. 华南理工大学材料科学与工程学院
3. 中国表面工程协会
通信作者: 赖德林 (1989-), 博士, 副研究员, 研究领域: 金属表面处理, E-mail: laidelin@scut.edu.cn

Preparation and Properties of Trivalent Chromium-Cerium Composite Passivation Films on Zn-5Al Alloy Coatings

LIU Zhihong¹, LI Yang², LIANG Guowei², SUN Guoqing³, LAI Delin²

1. Tianjin Youfa Steel Pipe Group Co., Ltd.
2. School of Materials Science and Engineering, South China University of Technology
3. China Surface Engineering Association
Corresponding Author: LAI Delin (1989-), Ph.D., Associate Researcher, Research Focus: Metal Surface Treatment, E-mail: laidelin@scut.edu.cn

文章历史: 收稿日期: 2026-06-11

摘    要
针对热浸Zn-5Al镀层易产生白锈、传统六价铬钝化毒性大且在该镀层上成膜效果不佳等问题，以硫酸铬[Cr₂(SO₄)₃]为三价铬源、硝酸铈[Ce(NO₃)₃]为成膜促进剂，采用正交试验优化钝化工艺，制备适用于Zn-5Al镀层的环保型复合钝化膜。通过醋酸铅点滴、中性盐雾、电化学测试及微观表征，系统研究钝化工艺参数对钝化膜耐蚀性能、微观结构与物相组成的影响。结果表明：最佳工艺为Cr₂(SO₄)₃ 4.0 g/L、Ce(NO₃)₃ 2.0 g/L、钝化时间60 s、温度为室温。该工艺制备的钝化膜均匀致密，主要由Cr₂O₃/Cr(OH)₃、CeO₂/Ce(OH)₄、Ce₂O₃/Ce(OH)₃复合构成，醋酸铅点滴变黑时间为75 s，经96 h中性盐雾后的镀层腐蚀面积仅4%；膜层极化电阻52 537Ω·cm²，腐蚀电流密度为2.865×10^-7 A/cm²，低频阻抗模值达1.47×10⁵ Ω·cm²，耐蚀性较六价铬钝化提升约4倍。该三价铬-铈盐复合钝化膜绿色环保、防护性能突出，可替代传统六价铬钝化应用于Zn-5Al合金镀层防护。

Abstract
To solve the issues that hot-dipped Zn-5Al alloy coatings easily develop white rust, and traditional hexavalent chromium passivation suffers from high toxicity and inferior film-forming ability on these coatings, eco-friendly composite passivation films were prepared for Zn-5Al alloy substrates. Using chromium sulfate(Cr₂(SO₄)₃) as the trivalent chromium source and cerium nitrate(Ce(NO₃)₃) as the film-forming accelerator, the passivation process was optimized via orthogonal tests. The effects of process parameters on the corrosion resistance, microstructure and phase composition of the passivation films were systematically investigated by lead acetate spot test, neutral salt spray (NSS) test, electrochemical measurements and microscopic characterization. The results showed that the optimal process parameters were as follows: Cr₂(SO₄)₃ 4.0 g/L, Ce(NO₃)₃ 2.0 g/L, passivation time 60 s and room temperature. The as-prepared passivation film was uniform and dense, which was mainly composed of Cr₂O₃/Cr(OH)₃, CeO₂/Ce(OH)₄, Ce₂O₃/Ce(OH)₃. The blackening time in the lead acetate spot test was 75 s, and the corrosion area of the coating was only 4% after 96 h of neutral salt spray test. The polarization resistance of the film was 52 537 Ω·cm², the corrosion current density is 2.865×10^-7 A/cm², and the low-frequency impedance modulus reaches 1.47×10⁵ Ω·cm². Its corrosion resistance was about 4 times higher than that of the hexavalent chromium passivation film. This trivalent chromium-cerium composite passivation film was eco-friendly and possesses excellent protective performance, which can replace traditional hexavalent chromium passivation for the anti-corrosion protection of Zn-5Al alloy coatings.

关键词
Zn-5Al合金镀层; 三价铬钝化; 硝酸铈; 复合钝化膜; 耐蚀性能

Keywords
Zn-5Al alloy coating; trivalent chromium passivation; cerium nitrate; composite passivation film; corrosion resistance

引用文本
刘志宏, 李阳, 梁国威, 等. Zn-5Al合金镀层表面三价铬-铈盐复合钝化膜的制备与性能[J]. 表面工程与再制造, 2026, 26(4): 19-31. DOI:10.26935/j.issn.2097-5317.2026.0021.

LIU Zhihong, LI Yang, LIANG Guowei, et al. Preparation and Properties of Trivalent Chromium-Cerium Composite Passivation Films on Zn-5Al Alloy Coatings[J]. Surface Engineering & Remanufacturing, 2026, 26(4): 19-31. DOI:10.26935/j.issn.2097-5317.2026.0021.

中图分类号
TG174.4

基金项目
金属表面高强微纳超双疏防护膜层构建的关键技术及应用研发 (2023B0101200008)

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