Technical note: Corrosion of welded aluminium coated steel in saturated H 2 S solution

Aluminium coated low carbon steel, welded using an austenitic stainless steel electrode, has been exposed to an acidified sodium chloride solution saturated with H₂S gas. The results show that pitting attack occurs in the Fe–Al alloy layer on the surface of the heat affected zone of the parent metal while electrochemical attack in the fusion zone is concentrated at the interface between the ferritic base metal and the austenitic weld metal. The results are discussed in the light of the published literature on mechanisms of H₂S induced degradation in steels.