Pressure Dependence of CO2 Effect on Hydrogen-assisted Fatigue Crack Growth in Two Pipeline Steels

Juan Shang; Shuanghe Chi; Ruizhe Gao; Baihui Xing; Aleksander Staykov; Zhengli Hua

Abstract

This study investigated the pressure-dependent CO2 effect on the hydrogen embrittlement of X80 and GB20# pipeline steels by combining experiments and first-principles calculations. Results revealed that the CO2 effect enhanced the fatigue crack growth for GB20# steel in 10 MPa CO₂-enriched hydrogen mixtures. However, the improved degree by the CO₂ effect at 10 MPa was less pronounced than at 0.4 MPa, which was found for the first time. This was attributed to the decreased adsorption rate of CO₂ on iron as hydrogen pressure increased. Therefore, in high-pressure CO₂-enriched hydrogen mixtures, CO2 could not significantly accelerate the inherent rapid hydrogen uptake at high pressure.

Funding source: This research is supported by the National Key Research and Development Program of China (Grant No. 2022YFB4003400), State Key Laboratory of Clean Energy Utilization and Zhejiang University K.P. Chao’s High Technology Development Foundation, JSPS KAKENHI Grant Number 24K22931. All authors gratefully acknowledge the support of the Center for Energy Systems Design (CESD), International Institute for Carbon-Neutral Energy Research (WPI–I 2 CNER), sponsored by the World Premier International Research Center Initiative (WPI), MEXT, Japan.

Keywords: Carbon Dioxide ; Embrittlement & Corrosion ; Fatigue Crack Growth Rate ; First-principles Calculations ; Hydrogen Embrittlement ; Materials & Components ; Pipeline Steel

Related subjects: Transmission, Distribution & Storage

Countries: China, People’s Republic ; Japan