Research On Single-Sided Alloy Coating Of Steel Plates By Hot-Dip Al-10%Si

The surface of steel contains pure aluminum layer after hot-dip aluminum. The pure aluminum layer not only has beautiful appearance, but also has good corrosion resistance. The diffusion of the aluminum and the substrate forms alloy layer which has good heat resistance. So aluminized steel plates are widely used in automotive exhaust systems, such as manufacturing exhaust pipes and mufflers and so on.7.5%to10%Si is added to melting aluminum, which can improve the fluidity of melting aluminum and the workability of steel plates. This kind of steel plates is called the I type. In order to meet good corrosion resistance of the interior walls of cars and other vehicles skin, we are making a study of single-sided aluminized steel plates. This type of steel plates ensures the anti-corrosion requirements on one side, and also has good mechanical properties on the other side.Silicate, alumina and quartz is as the formula of resistive layer in the experiment. Steel plates obtain single-sided aluminized coating by hot-dip Al-10%Si. It determines the best ratio of silicate, alumina and quartz according to the quality of the surface of steel plates. Looking for a good process of removing the resistive layer is another thing. On this basis, the performance of the steel plates is tested:The coating’s quality of single-sided aluminized steel plates is analyzed in comparison with double-sided aluminized steel plates; SEM-EDS composition analysis; optical microscope analysis of coating thickness; electrochemical polarization curve experiments. And then the plating resistance of the formula and the performance of the aluminum coating is evaluated.The results show:It has good plating resistance when the weight ratio of silicate, alumina and quartz is2:4:5;6%HF+0.3%Lan-826is used to remove the resistive layer; EDS composition analysis shows that there is no aluminum on the surface of the steel plates after removing the plating resist coating, so the formula achieves the desired effect; The resistive layer has little effect on the thickness of aluminum coating and the corrosion resistance of aluminum coating.