摘要
由于Cr(Ⅵ)对环境有不利影响,因此寻找不含Cr(Ⅵ)的钝化液非常重要。研究在连续热浸镀锌钝化液中以Cr(Ⅲ)、铈、钴替代Cr(Ⅵ),钝化液通过辊涂和烘干处理工艺得到钝化膜。试验通过电化学方法研究钝化膜的抗腐蚀行为。SEM形貌观察发现,所获得的钝化膜较Cr(Ⅵ)钝化膜具有更加致密的表面膜层,SiO2在膜层结构中阻碍了微裂纹的扩展,提高了膜层抗形变性能;电化学极化曲线研究表明,铈、钴抑制了阳极极化腐蚀过程;盐雾试验结果表明,复合钝化膜较传统钝化膜具有更好的抗蚀性能。钝化膜的膜附着量达70～80mg/m2,试样出现锈蚀的时间可以达到192h,试验色差为1.5。
Cerium salts, cobalt salts, and silicon dioxide were introduced to replace Cr(Ⅵ) fluid for continuous galvanizing of steel sheet. The microstructure of the resulting roller-coated and cured composite passivating film was analyzed by means of scanning electron microscopy, and its corrosionbehavior was evaluated using neutral salt-spray test (NSS).Results indicated that the composite film was more compact than that prepared from conventional Cr(Ⅵ) fluid, and it showed better corrosion resistance than Cr(Ⅵ) passivating film. This could be because SiO2 incorporated in the composite passivation film was capable of preventing propagation of microcracks and decreasingdeformation as well, while cerium and cobalt salts were able to retard anodic polarization.
出处
《材料保护》
CAS
CSCD
北大核心
2008年第11期8-10,共3页
Materials Protection
