Numerical Simulation on Hydrogen Induced Cracking Behavior of 4130X Hydrogen Storage Vessel With Defect

Abstract This study aims to investigate the hydrogen-induced cracking behavior of the cylinder of 4130X hydrogen storage vessel in a 45 MPa high-pressure hydrogen environment under the synergistic influence of hydrogen and crack depth. Firstly, finite element analysis was performed via a modified hydrogen diffusion/plasticity coupled model to study the coupling behavior of hydrogen diffusion and plastic deformation in a hydrogen storage vessel with a crack. Then we used the modified hydrogen diffusion/plasticity coupled model to study the effect of crack depth on the hydrogen-induced cracking behavior in the hydrogen storage vessel. Results show that the hydrogen is mainly concentrated in the trap at the crack tip of the vessel, and the crack tip is always the position with the highest total hydrogen concentration. The distribution of plastic strain and trap hydrogen concentration on the crack surface is small along the axial direction of the cylinder, but large along the radial direction of the cylinder. With the increase of the initial crack depth, the pressure difference corresponding to the crack propagation from radial direction to unstable propagation and the depth of the crack propagation show a decreasing trend, and the hydrogen pressure of unstable propagation also decreases gradually. The greater the depth of cylinder crack, the more difficult it is to prevent cylinder failure.