Benefits and Limitations of the Use of Pb, Sn and Bi Alloying Elements in Hot Dip Galvanizing Bath: A Review

Today, lead, bismuth and tin constitute the main group of alloying elements for zinc baths used for hot dip galvanizing. These metals improve the fluidity of liquid zinc, which positively affects the consumption of zinc and improves the appearance of the coating. However, their presence in the bath, despite their beneficial effects, is controversial due to the increased risk of liquid metal-assisted cracking (LMAC). Recent studies also indicate that these additives may contribute to lowering the corrosion resistance of coatings. The article analyzes the existing knowledge on the addition of lead, tin and bismuth to the bath and presents the benefits and limitations of using them as an alloying additive to the hot dip galvanizing bath.