A review on recent finite element modeling advancements for studying hydrogen embrittlement in steel

• A review of numerical methods for hydrogen embrittlement (HE) is provided. • Continuum damage models, cohesive zone models, extended finite element methods, and phase field methods are discussed. • Modeling techniques for HE mechanisms using numerical methods, with a focus on industrial applications, are reviewed. • The advantages and disadvantages of each method are discussed. Hydrogen, in addition to being the lightest and most abundant element in the universe, is also the smallest, which allows it to enter and diffuse through various materials. Thus, its presence particularly in steels, can lead to hydrogen embrittlement (HE), which poses a significant challenge in the integrity and reliability of these materials when exposed to hydrogen environments. As the global energy transition progresses, hydrogen is increasingly recognized as a clean energy carrier, making the study of HE more critical than ever for ensuring the safe and efficient use of hydrogen technologies. This review provides a comprehensive analysis of recent advancements (2017-present) in finite element-based numerical methods employed to study HE mechanisms. The mechanisms contributing to HE are examined, specifically decohesion-based and plasticity-driven mechanisms, to assess their impact on material degradation and fracture. The modeling of hydrogen transport is reviewed, considering diffusion laws, stress-driven diffusion, trapping phenomena, and their incorporation into numerical frameworks. Constitutive hydrogen degradation laws are analyzed for their ability to represent the degradation of mechanical properties due to hydrogen interaction. Additionally, plasticity modeling approaches are evaluated to assess their compatibility with various HE mechanisms. Four distinct numerical approaches (continuum damage mechanics model, cohesive zone model, extended finite element method and phase field method) are critically analyzed. Particular attention is given to their formulation, implementation strategies, integration of hydrogen transport models and effectiveness in simulating HE mechanisms as well as their synergistic interactions. Each method’s strengths, limitations and application scenarios are evaluated. This critical review aims to provide researchers with a clear understanding of the current state-of-the-art in HE modeling, identify gaps in existing finite element approaches, and propose future research directions to improve predictive capabilities for HE in steel.