Abstract
This study aims to investigate the structure and chemical composition of zinc-aluminum coatings with a grain defect. Defects and irregularities, such as localized thickening and adhered "grains", were noticed in the coating obtained from the Zn + 7 wt.% Al melts at 480 °C. As a solution, it was observed that the galvanizing temperature range of 410−460 °C maintains a thickness of 8−13 µm. At 480 °C, the coating thickness increases to 35−40 microns, and local defects in the form of grains measuring 110−120 microns appear. By analyzing the binary systems Al-Fe, Fe-Zn, and Zn-Al, and the ternary system Zn-A-Fe, conclusions were drawn about the phase composition of the defect and the possible reasons for its occurrence. Finally, the steps to rectify this issue have been outlined.

Key words
hot-dip galvanizing, Zn-Fe-Al system, Zn-Al coating, microstructure, intermetallic dross, coating defect

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