Qualitative and quantitative development of zinc baths for hot-dip galvanizing

The paper presents general characteristics of applications of zinc baths used in the past century for hot-dip galvanizing of steel articles in industrial conditions. The natural conditions under which a lead layer is formed at the galvanizing tank bottom have been described. The changes in chemical composition of the bath and the main types of defects of the coatings obtained using these baths have been presented. For each specified bath the sets of alloy additives used to improve quality of the produced coating are given, including currently produced universal coatings. Some errors in galvanizing technology resulting in poor appearance of the obtained coatings have been indicated. The differences in chemical composition of the phases present during hot-deep galvanizing have been discussed (zinc bath, hard zinc, ash, coating).