The effect of hydrogen evolution on corrosion pit growth under fatigue conditions

About the project

About the Project There is no funding attached to this project. The Industry and Innovation Research Institute (I2Ri) draws on talents, expertise and facilities across Sheffield Hallam University. The vision is to be the leading provider of applied research excellence delivering materials, computing, science and engineering innovations meeting the development needs of industry. PhD Research Topic: The transition to a hydrogen-based energy infrastructure is accelerating, bringing new challenges for the safe use of metallic materials in demanding environments. One of the most critical issues is the combined action of pitting corrosion, cyclic loading and hydrogen evolution , which can significantly reduce structural integrity and lead to premature failure. Corrosion pits act as local stress raisers from which fatigue cracks can initiate, while hydrogen generated within these pits can further accelerate damage through embrittlement mechanisms. Despite extensive research, the coupled interaction between pit growth, fatigue loading and hydrogen effects remains poorly understood. This project aims to address this challenge by developing a comprehensive experimental and modelling framework to investigate how hydrogen evolution influences corrosion pit growth and subsequent fatigue crack initiation and propagation . The work will generate new fundamental insight and support the development of predictive tools for engineering applications in hydrogen-rich environments. Project Overview: Pitting corrosion is widely recognised as one of the most damaging forms of localised corrosion, particularly in safety-critical structures. Under cyclic loading, pits evolve in both size and morphology, altering the local stress field and making fatigue life predictions highly uncertain. When hydrogen is present—either from the environment or generated electrochemically within the pit—the situation becomes even more complex. Hydrogen can interact with the microstructure and promote damage through mechanisms such as Hydrogen Embrittlement, yet a unified understanding of these mechanisms is still lacking. The project explores these interactions in a systematic and quantitative manner, bridging the gap between fundamental material behaviour and engineering design. Aims and Objectives: The primary aim is to understand and quantify the effect of hydrogen evolution on corrosion pit growth and fatigue behaviour. The objectives: · Characterise the evolution of corrosion pits under controlled environmental and loading conditions · Investigate the role of hydrogen in accelerating pit-to-crack transition · Quantify the influence of pit geometry on local stress/strain fields and fatigue life · Examine microstructural changes associated with hydrogen-assisted damage · Develop predictive models for fatigue life in hydrogen-active environments Experimental Programme: The project will involve a carefully designed experimental campaign combining corrosion, fatigue and hydrogen charging techniques. Metallic specimens will be subjected to controlled pitting conditions, followed by fatigue testing under well-defined loading histories. Key aspects: · Generation of corrosion pits with controlled size, depth and morphology · Fatigue testing under constant and variable amplitude loading · Exposure to environments promoting hydrogen evolution within pits · Investigation of the interaction between pit growth and cyclic deformation A major focus will be on replicating realistic service conditions relevant to hydrogen infrastructure, including pipelines, storage systems and offshore applications. Advanced Characterisation: You will use state-of-the-art experimental facilities, including high-resolution microscopy and in-situ measurement techniques. Including: 1. Scanning Electron Microscopy (SEM) for detailed fracture and microstructural analysis 2. Surface and subsurface characterisation to track pit evolution 3. Full-field strain measurements using Digital Image Correlation (DIC), enabling: · Identification of strain localisation around pits · Observation of crack initiation processes in real time · Quantification of deformation mechanisms influenced by hydrogen These techniques will provide a unique dataset linking microstructural evolution, pit geometry and fatigue behaviour. Modelling and Data Analysis: The experimental findings will underpin the development of advanced predictive models, including: · Fatigue life prediction methods incorporating pit geometry and hydrogen effects · Mechanistically informed models combining existing theories (e.g. HELP, HEDE, AIDE) · Integration of experimental data with AI-assisted analysis and modelling approaches · Exploration of multiscale modelling strategies linking microstructure to structural response The project will also consider uncertainty quantification and the development of robust design methodologies for engineering applications. Impact and Relevance: Understanding how hydrogen affects corrosion pit growth and fatigue performance is essential for the safe deployment of hydrogen technologies. This project will: · Provide new insight into hydrogen-assisted fatigue mechanisms · Support the design of more durable materials and structures · Contribute to the development of safer hydrogen infrastructure · Inform standards, guidelines and lifecycle assessment strategies The outcomes will be highly relevant to industries such as energy, transport, offshore engineering and infrastructure. Eligibility: All applicants should hold a strong undergraduate degree (2.1 or above) and/or a relevant masters qualification (or expectation of the same). Related disciplines include mechanical engineering and materials engineering. An interest in fatigue, corrosion, or experimental mechanics is desirable. Experience with microscopy, electrochemistry or numerical modelling is beneficial but not essential. We welcome applications from all candidates irrespective of age, pregnancy and maternity, disability, gender, gender identity, sexual orientation, race, religion or belief, or marital or civil partnership status. International candidates are required to provide an IELTS certificate with a score of at least 6.5 overall, and a minimum of 6.0 in all components. For further information on English Language requirements, please click here . For further details on entry requirements, please click here . How to apply: All applications must be submitted via the online application form . Please include the title of the project that you are applying for in your application. As part of your application, please upload: · A research proposal (max. 1500 words) in your own words, briefly outlining the proposed research, the current knowledge and context referencing key background literature; a proposed methodology or approach to answer the key questions, and any potential significance or impact of the research · Copy of your highest degree certificate · Non-UK applicants must submit IELTs results (or equivalent) taken in the last two years and a copy of their passport. Applicants must provide 2 references, with at least one to be academic. References must be received directly from the referees. We strongly recommend you contact the lead academic, Dr Matthew Kitchen – m.kitchen@shu.ac.uk , to discuss your application. For further information on how to apply please visit https://www.shu.ac.uk/research/degrees

Research areas