The hydrogen-assisted cracking (HAC) behavior of 2205 duplex stainless steel is investigated via experimental testing and computational modelling, with specific focus on developing a predictive methodology for the coupled effects of hydrogen diffusion and stress. The effects of duration and stress level on hydrogen-assisted fracture in the dual-phase microstructure are characterized via tensile testing of single-edge notch specimens under hydrogen diffusion conditions. Crack initiation and growth is shown to occur predominantly in the ferrite phase with the austenite phase acting to retard crack growth, leading to discontinuous crack patterns. Mixed brittle and ductile fracture characteristics were identified, due to the competitive effects of hydrogen-induced decohesion and localized plasticity. A key novelty is the development and verification of a sub-modelling finite element methodology of the dual-phase microstructure, incorporating hydrogen diffusion, coupled hydrogen-stress effects and cohesive zone cracking. The model consistently predicts observed crack length and mixed-phase induced crack morphology. Increased refinement of austenite phase is shown to increase fracture resistance of the dual-phase steel, consistent with published findings.

通过实验测试和计算模型研究了2205双相不锈钢的氢辅助开裂（HAC）行为，尤其着重于开发预测性方法，以预测氢扩散和应力的耦合效应。通过在氢扩散条件下对单边缘缺口样品进行拉伸测试，表征了持续时间和应力水平对双相组织中氢辅助断裂的影响。裂纹的产生和扩展主要发生在铁素体相中，而奥氏体相则阻碍了裂纹的扩展，导致了不连续的裂纹模式。由于氢致脱粘和局部可塑性的竞争效应，确定了混合的脆性和延性断裂特性。一个关键的新颖之处是开发和验证了双相微结构的子模型有限元方法，该方法结合了氢扩散，耦合的氢应力效应和内聚区开裂。该模型一致地预测观察到的裂纹长度和混合相诱导的裂纹形态。与已发表的发现一致，奥氏体相细化的增加显示出增加了双相钢的抗断裂性。