最全：锌铝镁镀层彩涂板产品好在什么地方？

天物彩板专注彩板行业16年——更多陕西锌铝镁镀层彩涂板产品优点请拨打网站上方电话咨询

1、 锌、铝、镁的耐蚀性及划痕切口自修复原理
首先，理论分析。ZAM板具有独特的耐腐蚀性，特别是缺口保护性能。可分为两种情况：平面无划痕和切口有划痕两种。
1当ZAM表面无划痕时
涂层中镁、铝的共同作用，在长期使用过程中，会在涂层表面形成一层致密、附着力高的氧化保护膜，将涂层与外部腐蚀环境隔离，起到隔离和防腐的作用，防止涂层腐蚀。镁是一种比铝更活泼的金属。在空气中很容易氧化。固体镁形成的氧化膜也很致密，能有效保护内部结构，防止进一步氧化。由于镁和铝的不同，镁在涂层中均匀而精细的分布使得氧化膜覆盖整个涂层表面，保护涂层中的所有结构。
当涂层被划伤或割伤时
从涂层中溶解出来的镁可以在切口截面上形成一层细小致密的含镁氧化膜，覆盖在划痕处或切口处暴露的钢基体，提高其耐蚀性。在这种情况下，还可以发挥锌的牺牲防腐作用和铝、镁的隔离防腐作用。在此基础上，由于镁具有很强的活性，可以减少钢板表面松散的氧化物，用致密的氧化镁代替，从而保护外露的钢基体。
在ZAM板新的切割位置，裸露的钢基体在腐蚀环境中会被氧化，初期会出现红锈。但随着时间的推移，镁、锌、铝从镀层中溶解，使红锈变为灰黑色的氧化膜，组织较致密，保护了断裂部位不被氧化。
切口暴露试验表明，试验开始时断口呈红色，但红色不会严重发展。三年后，原来的红色变成灰黑色。经检测，断口氧化膜中含有锌、镁、铝、氧、铁、氯、硫等复杂成分。

1、 Corrosion resistance of zinc, aluminum and magnesium and self repairing principle of scratched incision
First of all, theoretical analysis. ZAM plate has unique corrosion resistance, especially the notch protection performance. It can be divided into two cases: the plane without scratch and the two cases with incision and scratch.
1 when there is no scratch on ZAM surface
The joint action of magnesium and aluminum in the coating will produce a dense oxidation protection film with high adhesion on the surface of the coating in long-term use, which will isolate the coating from the external corrosion environment, play the role of isolation and corrosion prevention, and prevent the coating from corrosion. Magnesium is a more active metal than aluminum. It is very easy to be oxidized in air. The oxide film formed by solid magnesium is also dense, which can effectively protect the internal structure and prevent further oxidation. Due to the difference between magnesium and aluminum, the uniform and fine distribution of magnesium in the coating makes the oxide film cover the whole coating surface and protect all the structures in the coating.
When the coating is scratched or cut
The magnesium dissolved from the coating can form a fine and dense oxide film containing magnesium on the incision section, which can cover the steel substrate exposed at the scratch or the incision, so as to improve its corrosion resistance. In this case, the sacrificial anti-corrosion effect of zinc and the isolation anti-corrosion effect of aluminum and magnesium can also be brought into play. On this basis, because magnesium is very active, it can reduce the loose oxide on the steel plate surface and replace it with dense magnesium oxide, thus protecting the exposed steel base.
In the new cut position of ZAM plate, the exposed steel base will be oxidized in corrosive environment, and red rust will appear at the initial stage. However, with the passage of time, magnesium, zinc and aluminum dissolved from the coating will change the red rust into gray black oxide film, and the microstructure is relatively dense, which protects the fracture site from being oxidized.
The incision exposure test shows that the fracture surface appears red at the beginning of the test, but the red color will not develop seriously. After 3 years, the original red color turns to gray black. After testing, the oxide film on the fracture surface contains zinc, magnesium, aluminum, oxygen, iron, chlorine, sulfur and other complex components.