助镀剂中稀土盐含量对热浸镀锌层组构及性能的影响  

Effect of Rare Earth Salt Content in Fluxing Agent on Microstructure and Corrosion Resistance of Hot-Dip Galvanizing Coating

作　　者：曹文平[1] 何明奕[1] 刘洪锋[1] 王胜民[1] 赵小军[1] 

机构地区：[1]昆明理工大学材料保护研究所,云南昆明650093

出　　处：《材料保护》2013年第2期7-9,66,共3页Materials Protection

基　　金：国家自然科学基金(51161010);云南省自然科学基金项目(2011FZ053);云南省教育厅重点基金项目(2010Z018)资助

摘　　要：以往少见将稀土加入到助镀剂中对热浸镀锌层组构及性能影响的研究报道。为此,在助镀剂中添加混合稀土盐(主要成分为Ce和La)助镀后再热浸镀锌,利用金相显微镜(OM)、扫描电子显微镜(SEM)、电化学测试及全浸腐蚀方法考察了助镀剂中稀土盐含量对热浸镀锌层组织结构及耐蚀性能的影响。结果表明:助镀剂中添加稀土盐能够使镀锌层减薄,有利于改善镀层的微观组织结构,抑制脆性相ζ相的生长,获得由塑性较好的δ相组成的镀层;添加稀土盐有助于改善镀层的耐蚀性能,且耐蚀性能随着稀土盐含量的增加而增强,在稀土盐含量为0.2%时镀层的耐蚀性能最好,之后随着稀土盐含量的增加,镀层的耐蚀性能反而下降。Hotdip galvanizing coating was prepared by introducing rare earth salt into the fluxing agent.The morphology and microstructure of asprepared hotdip galvanizing coating were observed with a metallurgical microscope and a scanning electron microscope.The corrosion resistance of asprepared galvanizing coating was evaluated by conducting total immersion corrosion tests with an electrochemical test rig.Furthermore,the effect of the content of the rare earth salt in the fluxing agent on the microstructure and corrosion resistance of asprepared galvanizing coating was investigated.Results showed that introducing rare earth salt into the fluxing agent helped to reduce the thickness of the galvanizing coating,improve its microstructure,and inhibit the growth of brittle ζ phase thereby affording galvanizing coating mainly consisting of δ phase.In the meantime,introducing rare earth salt also contributed to the improvement of corrosion resistance of galvanizing coating,and the corrosion resistance of the galvanizing coating rose with increasing content of the rare earth salt.Particularly,the galvanizing coating obtained at a rare earth salt content of 0.2% had the best corrosion resistance,and further increase in the content of the rare earth salt led to worsening in the corrosion resistance of the galvanizing coating.

关 键 词：热浸镀锌层 助镀剂 稀土盐 组织结构 耐蚀性能 

分 类 号：TG174.443[金属学及工艺—金属表面处理]