Study On Manufacture Technology And Corrosion Resistance Of Zn-Mg Alloy Coatings By Evaporation

Hot dip galvanized steel products less erosion life extension, energy and materials play an irreplaceable and invaluable role. With the development of science and technology and the progress of human society, with the consumption of zinc resources, higher corrosion resistance and better economic performance of the new alloy coating, composite coating become a research and development focus. Zinc-magnesium alloy coatings due to their excellent corrosion resistance have received attention. Therefore, the vacuum preparation and corrosion properties of zinc-magnesium alloy coating deposition have important significance.In this paper, we use laboratory muti-function TU-750coating machine vacuum evaporation magnesium film on galvanized steel sheet, and then alloying forming zinc magnesium alloy coating on it. Through comparsion between the Zinc-magnesium coated steel and pure zinc coated steel, we can know more about Zn-Mg coated steel, using scanning electron microscope and spectrometer observation the surface and cross-section microstructure and doing component analysis of different coatings; the corrosion resistance of different coatings are studies by neutral salt spray corrosion test and full immersion test; through X-ray diffractometer, trimming on the surface of a coating on the corrosion products of XRD testing to analysis the phase composition. In addition, coated steel must undergo deformation so it can be made into the corresponding component. To study the properties of the comparative analysis of coatings by the cup drawing test deformation; comparative analysis of, Zinc-magnesium and pure Zinc study on the corrosion resistance of coated steel. Through the comparison, the comprehensive analysis of the organizational structure of the Zinc-magnesium and its corrosion mechanism. Through the above research mainly draw the following research results:(1) The corrosion resistance of Zinc-magnesium alloy coating has closely connected with the coating microstructure. Zinc-magnesium alloy layer is more stable than ordinary galvanized layer, it has a meticulous organization, more dense corrosion products. These beneficial characteristics ensure the excellent corrosion resistance of the coating, and even if under the bad environment.(2) Zinc-magnesium alloy coating after cupping deformation still has good corrosion resistance, Zinc-magnesium alloy coating steel side cutting part also showed the excellent corrosion resistance, greatly superior to pure zinc coating, the presence of magnesium is the main reason for the improvement of the cutting edges anticorrosive ability.(3) Zn-Mg alloy coating in electrochemical corrosion test exhibited high polarization resistance, because the magnesium ions tend to form a compound is not stable in the presence of an electrical double layer, Zn-Mg alloy coating are present in the anode polarization curve passivated areas.