Coatings obtained in Zn-Al-Mg baths on steel plates by using the continuous method provide effective protection against corrosion. They have greater corrosion resistance than traditional zinc coatings. Even though Zn-Al-Mg coatings have many advantages, they are not made on galvanized products by use of the batch hot dip method. For products galvanized by use of the batch hot dip method coating growth mainly depends on the content of silicon in the steel. An increase in coating thickness is particularly intense in the case of high-silicon steel. In the paper the results of tests on obtaining Zn-Al-Mg coatings on high-silicon steel by use of the batch hot dip method have been presented. The growth kinetics of coatings obtained in the Zn-31Al-3Mg bath on steel with Si content of 0.27% has been defined. The structure has been developed and the chemical composition of particular structural components of the coating has be established. It has been determined that coatings obtained in the Zn-31Al-3Mg bath are continuous and they have uniform thickness. The structure of the coating is compact and the chemical composition points to the presence of phases of the Fe-Al system. The presence of silicon in the steel limits steel reactivity in the tested bath. The course of growth kinetics of the coating is close to parabolic.
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 K. Nishimura, H. Shindo, K. Kato, Y. Morimoto, Microstructure and corrosion behavior of Zn-Mg-Al hot dip galvanized steel sheet, Proceedings of the 4th International Conference on Zinc and Zinc Alloy Coated Steel, GALVATECH, Chiba, Japan (1998) 437-442.
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