Influence of H2S on the general corrosion and sulfide stress cracking of pipelines steels for supercritical CO2 transportation

This article presents a literature review and corrosion testing outputs to fill the knowledge gaps about the effect of H2S on corrosion and sulfide stress cracking (SSC) of pipeline steels in supercritical CO2 (s-CO2) environments. In H2O-saturated s-CO2, H2S facilitates the formation of a protective FeS layer with a threshold content less than 50 ppm. Increasing temperature or adding O-2 destroys the integrity of FeS layer and remarkably enhances corrosion. The corrosion is likely to be controlled by gas chemical reactions instead of electrochemical reactions. The SSC susceptibility of strained pipeline steels is lower than expected.

Automated summary

In H2O-saturated supercritical CO2, H2S promotes the formation of a protective FeS layer, but increasing temperature or adding O-2 can destroy the integrity of this layer and enhance corrosion significantly. The corrosion is likely controlled by gas chemical reactions instead of electrochemical reactions, and the sulfide stress cracking susceptibility of strained pipeline steels is lower than expected.