摘要:镀锌层作为钢铁件上主要防止腐蚀的镀层,在电镀加工量中位居第一位。镀锌层是阳极镀层,当它和空气中的水蒸气发生电化学腐蚀的时候,为了钢基体得到保护,只能以腐蚀锌作为代价。电镀锌之后都需要进行钝化处理,是因为锌在大气中是很容易生成碱式碳酸锌腐蚀物而产生白斑、白灰和白毛。钝化除了使镀层有防蚀能力,还可以拥有不同的颜色,并且提高了镀锌层和油漆层之间的结合能力和其他功能。钝化种类非常复杂而且多,六价铬蓝白钝化是运用最多的一种钝化方式[1]。但是由于这种方法毒性很大,所以逐步严格限制了六价铬的蓝白钝化。因为在许多方面,三价铬钝化拥有和六价铬钝化相似的性能,但是毒性却比六价铬少的多,甚至不到它的0.01[2]。因此,三价铬蓝白钝化得到了更多的关注。43777
毕业论文关键词:镀锌; 三价铬; 兰白钝化;六价铬
The research about blue and white passivation coating on the surface of zinc
Abstract: Galvanized as the main corrosion protective coating of steel pieces, at the top of the list in the electroplating processing capacity. Zinc plating on steel parts for anode sex coating, when be affected with damp be affected with damp and electrochemical corrosion, first at the expense of zinc corrosion and make the steel substrate are protected. Whereas, in the atmosphere is very easy base type carbonate zinc corrosion, while long white spot, lime and white wool. So after galvanized passivation of all will be. Passivation and give different plating color is tonal, and improve the bonding force between the paint layer, and other functions. Hexavalent chromium passivation species is very complex, including blue white passivation technology is widely used in galvanized passivation layer. However, due to the toxic hexavalent chromium, gradually tightly restricted its application. Because the trivalent chromium passivation in many ways has similar properties to hexavalent chromium passivation, toxic hexavalent chromium is only one percent. Therefore, trivalent chromium passivation widely attention of the blue and white.
Keywords: acid zinc; trivalent chromium; blue white passivation; Hexavalent chromium
目 录
1 前言 1
1.1 锌镀层的概况 1
1.2 氯化钾镀锌的概况 1
1.3 镀锌的钝化介绍 2
1.3.1 高铬钝化 2
1.3.2 中铬钝化 2
1.3.3 低铬彩钝 2
1.3.4 超低铬彩钝 3
1.3.5 超低铬蓝白钝化 3
1.3.6 无铬蓝白钝化 3
1.4 钝化膜颜色 4
2.1 课题的任务内容 5
2.2 国内外研究的现状 5
2.3 未来的发展趋势 6
2.4 钝化液的组成 6
2.4.1 三价铬离子 6
2.4.2 络合剂 6
2.4.3 氧化剂 6
2.4.4 其它金属离子 7
2.5 钝化工艺的发展 7
2.6 镀锌的兰白钝化特点 7
2.7 镀锌的兰白钝化工艺存在的问题