30CrMo钢裂尖应力诱导氢扩散影响因素数值模拟研究

Numerical Simulation Study on the Influence of Stress-induced Hydrogen Diffusion at the Crack Tip of 30CrMo Steel

低合金钢在应力集中和高压氢气的交互作用下通常会产生以氢致开裂(HIC)为代表的环境致裂(EAC)现象。文章旨在研究高压储氢压力容器常用材料30CrMo钢在高压氢环境下的断裂力学行为,采用Abaqus/Explicit有限元软件建立30CrMo钢紧凑拉伸试样有限元模型,分析了应力强度因子及缺陷裂纹长度对裂纹尖端力学场、氢浓度场分布状态的影响。结果表明:裂尖应力强度因子的增大为裂纹扩展行为提供更大的驱动力;此外,在恒定外载条件下裂纹在扩展过程中裂尖驱动力呈逐渐增大的趋势。而裂尖所产生的奇异场将抑制可扩散氢在裂尖的最终分布状态。除去裂尖奇异场,裂尖氢浓度场随着应力强度因子的增加、裂纹长度的增加呈增大的趋势。

In low alloy steel,the combination of tension concentration and high hydrogen pressure results in environmentally induced cracking(EAC),also known as hydrogen induced cracking(HIC).This article’s objective is to investigate the fracture mechanical behavior of 30CrMo steel,which is commonly used in high-pressure hydrogen storage pressure vessels,under high-pressure hydrogen environment.The finite element model of compact tensile specimen of 30CrMo steel was established by Abaqus/Explicit finite element software.The influence of stress intensity factor and defect fracture length on the distribution of mechanical field and hydrogen concentration field at crack tip is analyzed.A higher driving force for fracture propagation behavior is provided by an increase in the stress intensity factor at the crack tip,as demonstrated by the findings.In addition,during crack propagation,when the external load remains constant,the driving force of the crack tip progressively increases.The singular field at the tip of the fissure will prevent the ultimate distribution of diffusible hydrogen there.Except for the singular field at the crack tip,the hydrogen concentration field at the crack tip increases with the stress intensity factor and crack length.