The aluminum in the zinc bath is added as a beneficial element. For general galvanized products and iron-plated zinc alloy products, aluminum is added as an alloying element for improving performance, and for aluminum galvanized and galvanized aluminum products Aluminum is an important part of the coating, so aluminum is more important. The following only describes the effects of aluminum when galvanized and iron-zinc alloy products. (1) The effect of aluminum on the galvanizing process has two aspects: First, aluminum inhibits the reaction between iron and zinc. After the steel strip enters the zinc solution, aluminum first reacts with iron to form a dense layer of iron-aluminum compound, which suppresses iron. Diffusion, so that the formation and thickening of the iron zinc compound layer is hindered. The second is that aluminum is conducive to the removal of zinc slag. This is also because aluminum is more active than iron. Aluminum can replace the iron in zinc slag to form aluminum zinc compounds and float off.
(2) The role of aluminum on galvanized products also has two aspects: First, aluminum improves the adhesion of the coating layer, and the iron-aluminum compound layer can play the role of the media, so that the steel base and the plating layer are tightly integrated, thereby improving plating. The stamping performance of the zinc plate does not cause the coating to fall off during deformation. Second, aluminum can improve the uniformity of the galvanized sheet, aluminum will make the coating less affected by the iron and zinc reaction, the coating thickness is uniform, and at the same time improve the appearance of the galvanized product.
(2) The role of aluminum on galvanized products also has two aspects: First, aluminum improves the adhesion of the coating layer, and the iron-aluminum compound layer can play the role of the media, so that the steel base and the plating layer are tightly integrated, thereby improving plating. The stamping performance of the zinc plate does not cause the coating to fall off during deformation. Second, aluminum can improve the uniformity of the galvanized sheet, aluminum will make the coating less affected by the iron and zinc reaction, the coating thickness is uniform, and at the same time improve the appearance of the galvanized product.