When the galvanized parts are tightly accumulated and placed in a humid air, electrochemical corrosion will occur due to the local surface of the plating on the surface of the plating without freely flowing air plating, forming white rust. Due to the coagulation water and oxygen on the surface of the galvanized layer. After the effect of carbon dioxide, hydrogen sulfide, sulfur dioxide, oxide, etc., after the effect of other chemical gas, it will produce a corrosive aqueous solution and attach to the surface of the zinc layer to form an electrolyte. As a result, the local white dot -shaped substance (zinc oxide) white rust is generated by the naked eye, and the local black appearance of white rust secondary and third -time oxidation products is collectively referred to as the phenomenon of alkali return.
