La对A3钢表面Zn-Fe-P合金镀膜耐蚀性能的影响

Effect of Lanthanum on the Corrosion Resistance Performance of Zn-Fe-P Alloy Coating

采用脉冲电流法在A3钢表面电镀Zn-Fe-P合金薄膜。用稳态法和静态挂片法研究镧对镀层耐蚀性能的影响,用SEM、EDS和XRD研究镀层的形貌、组成和结构。结果表明:在30℃的NaCl水溶液中,镧对Zn-Fe-P合金镀层有较大的耐蚀性能,使镀层的致钝电流密度(ipp)明显降低,致钝电位(φp)负移,维钝电流密度(ip)降低;在20℃的模拟海水中,镧对Zn-Fe-P合金镀层亦有一定的耐蚀性能,使镀层的腐蚀速度降低。SEM测试表明,镧对镀层起明显的细化作用;EDS测试表明,Zn-Fe-P合金电镀中P的含量为0.19%左右;XRD测试表明,在镀液中加入镧盐,能使镀层的(002)晶面择优取向增强。

Pulse electroplate was used to produce Zn-Fe-P alloy coating on the surface of A3 steel substrate, Effect of lanthanum on the corrosion resistance performance of the coating was studied by the galvanostatle method and static hang piece method. The appearance and composition and structure of the coatings was studied by SEM and EDS and XRD. The results indicate lanthanum has the better corrosion resistance performance on the coatings in the 3.5%NaCl solution at 30℃. It make the ipp and ip of the cloy coatings to reduce and φp move to negative direction. Lanthanum has some corrosion resistance performance on the coatings in the artificial sea water at 20℃. It make the corrosion rate of the coatings to decrease. The SEM test indicate that lanthanum make the crystal size of the coatings to diminish. The EDS test indicate that P content is 0.19% in Zn-Fe-P cloy coating, The XRD test indicate that lanthanum make （002）crystal orientation of cloy coating to increase.