Kinetics of Galvanic Corrosion of Carbon Steel to Arsenic and Antimony Couples

Abstract

Carbon steel has been observed to experience accelerated corrosion in some pH adjusted geothermal brines. The damage mechanisms observed in service have included; localised under-film corrosion, galvanic corrosion and erosion corrosion. The magnitude of these differing damage mechanisms has been difficult to deduce from the in-service history of corrosion and a laboratory study has been initiated to better quantify the effects of pH, temperature, aeration and chloride content on localised corrosion under heavy metal scales and galvanic corrosion. The study of antimony has progressed as this material is readily available in solid form. Arsenic is not readily available and a programme of work with vapour deposited arsenic layers on carbon steel initiated. This paper will describe progress in the study of the corrosion properties of galvanic couples of carbon steel to antimony and carbon steel to arsenic in laboratory solutions at temperatures up to 80⁰C.