Hydrogen induced cracking susceptibility in different layers of a hot rolled X70 pipeline steel

• Published in: International journal of hydrogen energy Vol. 38; no. 31; pp. 13831 - 13841
• Main Authors: Mohtadi-Bonab, M.A., Szpunar, J.A., Razavi-Tousi, S.S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 17.10.2013; Elsevier
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Coincidence site lattice (CSL) boundaries; Cracks; Crystallographic texture; Density; Energy; Exact sciences and technology; Fracture mechanics; Fuels; Grain boundaries; High angle grain boundaries (HABs); High strength low alloy steels; Hydrogen; Hydrogen permeation; Hydrogen traps; Low angle grain boundaries (LABs); Planes; Steels; Surface layer; Texture; Hydrogen permeation; Low angle grain boundaries (LABs); High angle grain boundaries (HABs); Hydrogen traps; Crystallographic texture; Coincidence site lattice (CSL) boundaries; Hydrogen; Steel; Grain boundary; Pipeline
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2013.08.046

Hydrogen induced cracking (HIC) behaviour was investigated in three layers of RD–ND plane. HIC test showed that all cracks initiated from the mid-thickness of the RD–ND plane and propagated in the rolling direction of the steel plate. Hydrogen permeation test results showed a lower permeability and diffusivity coefficient for the third layer resulting in the highest density of traps and consequently HIC susceptibility. Considering the HIC test and crystallographic texture measurements, cracks initiated from the grain boundaries associated with {100} grain orientation and arrested in regions with some strong texture components, such as {110}//ND, {112}//ND, and possibly {332}//ND. The role of HABs and CSLs boundaries was important in crack propagation. •Hydrogen permeation test showed the highest susceptibility of the third layer to the HIC.•The density of total traps and reversible traps at the third layer was higher than in other layers.•Strong resistant textures in a region were not suitable criterion for evaluation of HIC resistance.•Some especial texture components were observed after the crack path.•The role of HABs and CSLs boundaries was considerable in crack propagation.