Research progress of hydrogen compatibility testing methods and hydrogen embrittlement prevention measures for pipeline steel

Abstract

Understanding the causes of hydrogen embrittlement and its detrimental effects is essential for ensuring the integrity of pipeline steel. Various testing methods, including slow strain rate and fatigue life testing, are commonly employed to evaluate the susceptibility of metals to embrittlement. Pipeline steel materials often exhibit reduced toughness, accelerated crack propagation, and other hydrogen-related damage during slow strain rate tests conducted at hydrogen pressures below 5 MPa or in environments with a hydrogen volume fraction of 10% in blended natural gas. To simulate the conditions of steel serving in a hydrogen-rich environment,experiments incorporate methods of gas-phase hydrogenation and electrochemical hydrogenation. The former simulates the effects of different gas-phases on hydrogen embrittlement, while the latter replicates long-term hydrogen permeation. This paper provides an overview of the process and mechanisms of hydrogen embrittlement and analyzes three technologies for prevention and control:(1) modification of pipeline steel materials and processing techniques to optimize microstructure, enhance diffusion rates,and mitigate hydrogen atom aggregation;(2) introduction of gas inhibitors to slow hydrogen molecule adsorption on material surfaces through competitive adsorption; and(3) utilization of coatings on the inner pipeline wall to provide a barrier between hydrogen and the steel. Based on these insights, the paper offers suggestions for further optimizing pipeline hydrogen embrittlement control technology.

Keywords

• hydrogen embrittlement
• pipeline steel
• coating
• gas inhibitor