Hydrogen uptake during active CO2-H2S corrosion of carbon steel wires in simulated annulus fluid

Abstract

The hydrogen uptake of five carbon steel wires exposed to a corrosive CO2/H2S environment where protective film formation was not favorable was measured. The hydrogen uptakes decreased with the accumulation of retained carbide for most of the materials. It is assumed that hydrogen adsorbed on carbides at some distance from ferrite will not easily diffuse to the steel, hence giving the beneficial effect. This effect was not observed for the material with the lowest carbon content. Apart from this material, the hydrogen uptake increased with the carbon content, probably due to hydrogen trapping on ferrite-cementite interfaces.