Cheng, FrankSun, Yinghao2021-07-192021-07-192021-07-13Sun, Y. (2021). Dissociative Adsorption, Absorption and Permeation of Hydrogen on Steel Pipelines (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.http://hdl.handle.net/1880/113646Hydrogen is a green, clean fuel. Development of hydrogen energy is critical to achieving the net-zero emission target. Pipelines provide a promising alternative for hydrogen transportation. However, hydrogen embrittlement becomes a major concern to the safety of the pipelines. This research investigates entrance and permeation of hydrogen by modelling and experimental methods. Dissociative adsorption on Fe (100) could happen in wide temperature/pressure ranges, but spontaneous dissociation could be neglected as an effective H-atoms source. Fe-H bonds are formed by hybridization via charge accumulation on H atoms and weakened by coverage and stress. Corrosion enhancement following mechano-electrochemical (M-E) interaction is found at heat affected zone (HAZ) of X80 weld, where substantial hydrogen trapping sites are included. Elastic stress elevates hydrogen entrance and diffusion while plastic stress slows down diffusion but further increase hydrogen uptake. Stress concentration near weldment and interactions between hydrogen permeation and stress would lift degradation susceptibility at HAZ.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.Density functional theoryFinite element methodHydrogen pipelineMaterials Sciencemaster thesis10.11575/PRISM/39020