The corrosion of St37 carbon steel and 316 stainless steel in molten zinc bath

Corrosion tests were conducted on St37 carbon steel and 316 stainless steel in three different molten zinc baths. It was found that، the corrosion rate of stainless steel sample was higher than that of carbon steel. Beside chemical composition of bath، steel chemical composition affected their resistance to corrosion. Available high carbon in steel resulted in forming thick layers on surface of St37 steel and reducing the corrosion. Thin behaviour come be attributed to the thinner intermetallic layer formed on S. S. than that formed on St37 stee which has been confirmed by microscopic examinations. Available lead in bath affected 316 steel coating. The presence of lead in the bath results in the dendritic structure of coating and growth of surface grains which cause to increase the more penetration of zinc into coating.