Work

Influence of H2S and CO2 Partial Pressures and Temperature on the Corrosion of Superduplex S32750 Stainless Steel

Year: 2025

Type: article

Abstract: This study analyzes the effects of varying H2S and CO2 concentrations and temperature on the pH of geothermal fluids flowing through superduplex S32750 stainless-steel pipelines, classified as corrosion-resistant alloys (CRAs). Corrosive decay is evaluated by comparing OLI Studio software simulations with experimental data from the literature. The results indicate that an increase in the partial pressure of either gas lowers pH levels, with temperature exerting a more pronounced exponential effect on corrosion than gas partial pressure. When both gases are present, the dominant gas dictates the corrosion behavior. In cases where CO2 and H2S are in equal proportions, FeS2 forms as the primary corrosive product due to the higher potential corrosivity of H2S. The H2S/CO2 ratio influences the formation of passive films containing chromium oxides or hydroxides (Cr2O3, Cr(OH)3), iron oxides (Fe2O3, Fe3O4), or iron sulfides (FeS).

Source: Corrosion and Materials Degradation

DOI: 10.3390/cmd6020020

Authors: Naroa Iglesias, Esperanza Díaz

Institutions: University of the Basque Country, Centre for Electrochemical Technologies, Basque Center for Materials, Applications and Nanostructures

Language: English

Topic: Corrosion Behavior and Inhibition

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,207

Funder: Eusko Jaurlaritza