Hydrogen fracture maps for sheared-edge-controlled hydrogen-delayed fracture of 1180 MPa advanced high-strength steels

• Published in: Corrosion science 2021-05, Vol.184, p.109360, Article 109360
• Main Authors: Li, Huixing, Venezuela, Jeffrey, Qian, Zhen, Zhou, Qingjun, Shi, Zhiming, Yan, Ming, Knibbe, Ruth, Zhang, Mingxing, Dong, Futao, Atrens, Andrej
• Format: Article
• Language: English
• Subjects: A. hydrogen embrittlement; B. advanced high-strength steel; C. shear; Crack initiation; D. DP 1180; Dual phase steels; E. Q&P 1180; High strength steels; Hydrogen; Plastic deformation; Shearing; U bends
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2021.109360

•Hydrogen-induced delayed fracture (HIDF) was studied using shear-cut U-bend specimens.•Maps identified the conditions that cause HIDF.•HIDF was controlled by the sheared edge and required a critical amount of plastic strain.•Differing response was related to the microstructure interaction with the strains introduced by shearing.•A hydrogen enhanced plasticity (HEP) mechanism caused HIDF. Hydrogen-induced delayed fracture (HIDF) of 1180 MPa martensitic (MS), dual-phase (DP), and quenched and partitioned (Q&P) advanced high-strength steels was studied using shear-cut U-bend specimens. Fracture maps identified the conditions that caused HIDF. HIDF initiation was largely independent of the bending strain, and was controlled by the sheared edge, creating the critical amount of plastic strain damage required for HIDF. A hydrogen enhanced plasticity (HEP) mechanism caused HIDF. Differing responses to HIDF of the three steels were related to how the microstructures interacted with the stress and strains introduced by shearing. Exploratory work indicated that shear burr arrangement had little influence.