A review of the chemical and physical phenomena of modern hot-dip galvanizing processes is presented. The galvanizing process consists of the deposition of the coating formed by a rapid reaction of the zinc alloy with the steel substrate as the sheet pases continuously through the bath. The chemical and physical phenomena of the growth of the coating layer are presented, based on diffusion and interface reaction models. Exceeding the solubility limit of Al and Fe in the bath results in the precipitation of intermetallic particles which can nucleate in regions of variable composition. Both numerical and physical models have also been developed to describe the bath flow and movement of the particles in the bath in order to minize their entrapment and to improve the operating process.
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