为提高机械镀锌层的防腐性能，采用离心浸镀的方法在机械镀锌层表面分别制备了拉斯派特涂层和路锈宝涂层。通过金相显微镜观察分析了涂层的表面形貌，结合扫描电镜(SEM，配备有EDS能谱)表征了涂层截面形貌和涂层元素分布；采用XRD分析了涂层的盐雾腐蚀产物；利用划线划格法测试分析了涂层的结合强度；采用贴滤纸法检测了涂层的孔隙率；通过盐雾试验评价了涂层的耐腐蚀性能。结果表明：机械镀锌复合涂层是由机械镀锌层和后涂覆层复合而成，镀层和涂层的结合界面没有气孔、剥离和裂纹等缺陷；镀层表面的2类涂层均由鳞片状Al交替堆叠；盐雾腐蚀产物主要有Zn5(CO3)2(OH)6、Mg4Al2(OH)14·3H2O、Al2SiO5、Zn4CO3(OH)6·H2O、ZnCO3；2种后处理涂层与镀锌层的结合强度较好；2种涂层表面的孔隙率均为0；拉斯派特涂层出现红锈的时间为1 000 h，相比机械镀锌层的延长了650 h，路锈宝涂层出现红锈的时间为1 500 h，相比机械镀锌层的延长了1 150 h。综上所述，机械镀锌层表面复合拉斯派特和路锈宝涂层均显著延长了镀层的使用寿命，路锈宝涂层的效果更佳。拉斯派特和路锈宝涂层作为机械镀锌后处理工艺具有广阔的应用前景。
For improving the anti - corrosion performance of the mechanical galvanized layer, the centrifugal dipping was used to prepare the Ruspert coating and the Luxiubao coating on its surface independently. The surface morphology of the coatings was observed and analyzed with a metallurgical microscope. The cross - sectional morphology and element distribution of coatings were characterized by scanning electron microscope (SEM, equipped with EDS energy spectrum). The salt spray corrosion products of the coatings were analyzed by XRD, and the adhesive strength of the coatings was tested and analyzed through the cross - cut method. Moreover, the porosity of the coatings was tested by the filter paper method, and the corrosion resistance of the coatings was evaluated by the salt spray test. Results showed that the mechanical galvanized composite coating was composed of a mechanical galvanized layer and a coating prepared on it subsequently. The bonding interface between the mechnical galvanized layer and the coating had no pores, spallings or cracks. In addition, the two types of coatings were both formed by alternately stacked scaly Al. The salt spray corrosion products mainly included Zn5(CO3)2(OH)6, Mg4Al2(OH)14·3H2O, Al2SiO5, Zn4CO3(OH)6·H2O and ZnCO3. The adhesive strengthes between the two post - treatment coatings and the galvanized layer were good, and the surface porosity of the two coatings was zero. The time for the appearance of red rust for the Ruspert coating was 1 000 h, which was 650 h longer than that for the mechanical galvanized layer, while the time for the appearance of red rust for the Luxiubao coating was 1 500 h, which was 1 150 h longer than that for the mechanical galvanized layer. To sum up, the application of Ruspert and Luxiubao coatings on the surface of the mechanical galvanized layer could significantly extend the service life of the galvanized layer, and the effect of Luxiubao coating was better. The Ruspert and Luxiubao coatings had broad application prospects as post - treatment processes for mechanical galvanizing.
