Low-cycle fatigue mechanical behavior of 30CrMo steel under hydrogen environment and numerical verification of chaboche model

Abstract

In order to investigate the fatigue behavior of the hydrogen storage material, 30CrMo steel, in a hydrogen environment, an electrochemical hydrogen charging method was employed. Low-cycle fatigue experiments were conducted on the material to obtain half-life stress–strain hysteresis curves, cyclic response characteristics, and strain-life relationships under different hydrogen charging durations. The results indicate that the material exhibited an overall cyclic softening behavior, transitioning from ductile fracture to brittle fracture after hydrogen charging, resulting in a significant reduction in fatigue life. The Manson-Coffin formula was fitted based on material cyclic response characteristics and strain-life relationship curves. Additionally, fatigue toughness and Chaboche kinematic hardening models were fitted based on low-cycle fatigue test data. Finite element analysis was used to validate the accuracy and reliability of the Chaboche kinematic hardening model. The Chaboche kinematic hardening model showed minimal error compared to experimental data and accurately described the influence of hydrogen on the low-cycle fatigue mechanical behavior of 30CrMo steel.

Keywords

• 30CrMo
• Low-cycle fatigue
• electrochemical hydrogen charging
• mechanical properties
• Chaboche model