Physical Modeling of Steel Resistance to Hydrogen Embrittlement

Abstract

Hydrogen can be used in the same energy processes as natural gas and become a tool for implementing the transition to a sustainable low-carbon economy. The level of contamination resulting from controlled combustion of hydrogen or methane-hydrogen mixture is relatively low, which will significantly reduce CO2 emissions. However, the use of hydrogen can involve considerable difficulties associated with the hydrogen compatibility of materials. With the increase in the production, storage and transportation of hydrogen gas, including through gas pipelines, hydrogen-resistant materials are needed. The main problem with hydrogen is its embrittling effect. Under the influence of hydrogen, pipelines materials can probably have the following: hydrogen charging of the surface layer under pressure, loss of plasticity at tensile loads, formation of cracks and blisters (by decogesia mechanism), diffusion to the stress concentrator according to adsorption theory, accumulation of hydrogen at the top of the crack (which can lead to cracking) and so on. To assess the possibility of using a pipeline system for transportation of hydrogen gas in large volumes, it is necessary to know hydrogen compatibility of pipe steel. Physical modeling of steel resistance to hydrogen embrittlement can be carried out using electrochemical and gas charging methods.

Effect of Dissolved CO2 on the Interaction of Stress and Corrosion for Pipeline Carbon Steels in Simulated Marine Environments

“…However, CO 2 has been observed to have a strong impact on the corrosion rates of pipeline steels [4,5]. CO 2 enhances cathodic reaction rates and can also have a direct contribution to hydrogen charging of the steel's surface layer, especially when under pressure, resulting in the loss of ductility at tensile loads and the formation of blisters or cracks [5,6]. The risk of hydrogen embrittlement of these steels, associated with CO 2 transportation, is one of the major concerns related to their usage [4].…”

“…Fe 2+ + CO 3 2− → FeCO 3 (6) Carbon steels in pipeline applications are subjected to two forms of stress corrosion cracking (SCC): high-pH SCC and near-neutral pH SCC [17,18]. High-pH SCC is characterized by an intergranular mode of cracking and has been observed in concentrated carbonate/bicarbonate solutions with pH values higher than 9 [19][20][21][22].…”