Effect of Cu Content on Hydrogen Diffusion Behavior in Cu x Ni 2.7 Mn and Numerical Simulation Study

This study investigates the effects of Cu content (1.35, 3.10, and 6.01 wt.%) on hydrogen diffusion behavior and hydrogen embrittlement resistance in Cu x Ni 2.7 Mn low‐carbon steel, supplemented by numerical simulations using a cellular automata (CA) model. Through hydrogen permeation experiments, mechanical property testing, and fracture surface analysis, this study systematically analyzed hydrogen diffusion parameters, hydrogen trap density, and hydrogen embrittlement susceptibility at different Cu contents. CA simulations revealed hydrogen accumulation at grain boundaries and Cu‐rich precipitation interfaces, along with copper’s reversible regulation of hydrogen distribution. Results indicate that increasing Cu content leads to grain refinement, enhanced Cu‐rich precipitation, elevated hydrogen trap density, reduced effective hydrogen diffusion coefficient, and significantly diminished hydrogen embrittlement susceptibility. Optimal hydrogen embrittlement resistance is achieved within the 3.60–5.40 wt.% Cu content range. This study provides theoretical and experimental foundations for the composition design and engineering application of Cu‐containing steels with high hydrogen embrittlement resistance.