Surface treatment chemicals zinc plating

Related problems are caused by the presence of weak, friable oxide layers on the surface of the zinc plate itself However, the surface will respond well to appropriate chemical treatment. By contrast, the adhesion of the protective layer of zinc to the underlying steel presents an obstacle of greater dimensions. The real answer to this must lie in the hands of the metallurgist. However, an interim solution is the creation and use of adhesives whose shear modulus is such that it will distribute the imposed load properly and prevent anticipated stresses approaching the level which will rupture the steel/zinc interface. Such a technique... 

Chemical conversion processing is a type of surface treatment that consists only of a chemical reaction. In this respect, metal is immersed in a solution where it dissolves slightly, and an insoluble corrosion product, or an oxide film forms simultaneously on the surface. Examples of such films are corrosion resistant films, undercoat films, and lubrication films. Examples of chemical conversion processing are phosphating and chromic acid treatment. The following is an example of the use of a LCA in the phosphating of zinc plates. 

---