锌液中各元素对热镀锌彩涂板的影响

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1铅的影响
自然界中总有铅锌共生矿床。在炼锌过程中，虽然经过多次整改，但各级成品锌中仍有一定量的铅。需要注意的是，热浸镀锌时，液态锌中总会添加一些铅。铅在锌液中450℃的溶解极限为1.5%。如果铅的加入量超过了这个饱和浓度，锌锅底部就会出现铅层。
铅的存在还降低了锌液的粘度和表面张力，增加了锌液对铁表面的润湿性。在热镀锌过程中，在锌浴中加入铅，可以使镀层表面获得美观的大锌片，同时可以改善锌液在钢板上的浸泡条件，从而缩短带钢的浸泡时间
2铁的影响
当锌液温度为450℃时，铁在锌液中的最大溶解度（饱和浓度）为0.03%。如果铁含量继续增加，铁与锌结合形成铁锌合金，沉入锅底，称为底渣。另外，铁容易与铝结合形成底渣，降低了有效铝含量，从而降低了涂层的附着力。此外，铁的存在会增加锌液的粘度和表面张力，从而恶化锌液在钢板上的润湿状况，延长镀锌时间。
三。锑的影响
在锌液中加入锑，可得到美观的锌花。
4其他因素的影响
除上述元素外，还有一些其他杂质元素，大部分是由于与锌矿石共生，在锌冶炼过程中没有留下干净的杂质（如镉、锡、锑），还有一些不可避免地被带入生产过程（如铁）。
锌浴中杂质元素的含量对镀锌有一定的影响，主要包括以下几个方面：
4.1影响涂层的性能和结构。如果铁在锌溶液（如镉、锑）中的溶解速率增大或减小，铁锌合金层变厚或变薄，液态锌流动性增加或纯锌层变薄或变厚（如铁），则锌的脆性增加，涂层会变脆（如砷）；

1. Effects of lead

There are always lead and zinc coexisting deposits in nature. In the process of smelting zinc, although it has been rectified many times, there is still a certain amount of lead in the finished zinc of all levels. It should be noted that some lead is always added to the liquid zinc when hot-dip galvanizing. The dissolution limit of lead in liquid zinc at 450 ℃ is 1.5%. If lead is added beyond this saturation concentration, lead layer will appear at the bottom of zinc pot.
The existence of lead can also reduce the viscosity and surface tension of liquid zinc, which can increase the wettability of liquid zinc to iron surface. In the process of hot galvanizing, adding lead into the zinc bath can make the surface of the coating obtain beautiful large zinc flakes, at the same time, it can improve the immersion condition of the molten zinc on the steel plate, so as to shorten the soaking time of the strip steel
2. The influence of iron
When the temperature of liquid zinc is 450 ℃, the maximum solubility (saturation concentration) of iron in liquid zinc is 0.03%. If the iron content continues to increase, iron will combine with zinc to form iron zinc alloy and sink into the bottom of the pot, which is called bottom slag. In addition, iron is easy to combine with aluminum to form bottom slag, which can reduce the effective aluminum content, so the adhesion of the coating will be deteriorated. In addition, the existence of iron can increase the viscosity and surface tension of molten zinc, which will worsen the wetting condition of molten zinc on steel plate and prolong the galvanizing time.
3. The influence of antimony
The beautiful zinc flower can be obtained by adding antimony into the liquid zinc.
4. Influence of other elements
In addition to the above elements, there are also some other impurity elements, most of which are due to symbiosis with zinc ore, which are not left clean during zinc smelting (such as cadmium, tin, antimony), and some are inevitably brought into the production process (such as iron).
The content of impurity elements in zinc bath will have some influence on zinc plating, which mainly includes the following aspects:
4.1 affect the properties and structure of the coating. If the dissolution rate of iron in zinc solution (such as cadmium and antimony) is increased or decreased, the iron zinc alloy layer will become thicker or thinner, and the fluidity of liquid zinc will be increased or the pure zinc layer will be thinned or thickened (such as iron), the brittleness of zinc will be increased, and the coating will become brittle (such as arsenic);