Structures of coatings obtained in a ZnAl23Mg3Si0.4 bath by the batch hot dip method

Abstract

The paper presents the results of the tests on ZnAl23Mg3Si0.4 coatings obtained by use of the batch hot dip method. The growth kinetics of coatings obtained at the temperature of 520 • C on low-silicon steel has been defined. The structure has been developed, the chemical composition of structural components of the coatings and their phase composition have been established. It has been determined that coatings obtained in a ZnAl23Mg3Si0.4 bath are continuous and their average thickness ranges from 35.8 to 45.5 µm. The obtained coatings are composed of a diffusion layer of phase FeAl3 which contains Zn and Si and of an internal layer which contains solutions of Al and Zn as well as phases MgZn2 and Mg2Si.

The Multi-Stage Drawing Process of Zinc-Coated Medium-Carbon Steel Wires in Conventional and Hydrodynamic Dies

“…In the case of drawing zinc-coated wire, this layer consists of zinc coatings and a steel substrate [9]. In hot-dip zinc coating, the properties of the zinc coating depend largely on the galvanizing technology, including the composition and temperature of the bath and the immersion time [9][10][11][12]. In contrast to drawing uncoated wire, a very high variation in physicochemical properties between individual wire layers exists in the surface layer of zinc-coated wire at a depth of approximately 100 µm.…”

Archives of Metallurgy and Materials

“…The formation of a zinc coating is very complex and proceeds as a result of the simultaneously occurring partial processes of reaction diffusion, dissolution and secondary crystallization. To improve the corrosion resistance of coatings, Al and Mg are added to the bath [6]. The rate of zinc coating formation and the microstructure of the coating depend not only on the galvanizing technology alone, but also on the chemical composition of the steel, and particularly the Si content [7].…”