An Investigation on the Corrosion behavior of 316 Stainless Steel and 1015 Carbon steel in molten zinc bath

Corrosion tests on 1015 low-carbon steel and 316 stainless steel were conducted in two molten zinc baths in order tostudy the reaction mechanisms that occur during the degradation of submerged hardware at industrial hot dip galvanizing baths. It was found that, in general, 1015 carbon steel has a better dissolution resistance than 316 stainless steel, despite of the fact that there are high percentage of Cr and Ni in 316 stainless steel, and that the 316 stainless steel have a face-centered-cubic (FCC) structure which is more compact than 1015 carbon steel with a body-centered-cubic (BCC). Microscopic studies showed that a reason for the difference of corrosion behavior of these two steels, is that the thickness of inter-metallic layer is thinner on the stainless steel than 1015 carbon steel. The presented lead in the bath had no penetration into the formed coating on 1015 carbon steel while it affected 316 steel coating. The presence of lead in the bath results in the dendritic structure of coating and growth of surface grains which causes more penetration of zinc into coating.