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Influence of load interaction and hydrogen on fatigue crack growth behavior in steel pipelines under mean load pressure fluctuations
Author(s) -
Tehinse Olayinka,
Lamborn Lyndon,
Chevil Karina,
Gamboa Erwin,
Chen Weixing
Publication year - 2021
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/ffe.13414
Subject(s) - materials science , structural engineering , corrosion fatigue , paris' law , fracture mechanics , crack closure , pipeline transport , magnitude (astronomy) , amplitude , pipeline (software) , corrosion , mechanics , composite material , engineering , physics , quantum mechanics , astronomy , environmental engineering , mechanical engineering
Crack propagation in near neutral pH (NNpH) environment causes significant threat to pipeline integrity. Internal pressure fluctuations during pipeline operation create variable amplitude loading condition that can propagate corrosion fatigue cracks in NNpH environments. This study is aimed at understanding the effect of load interaction due to mean load pressure fluctuations on crack propagation in pipeline steel under NNpH conditions. The loading condition involved underload followed by an overload at set intervals among minor cycles. The effect of minor cycles, magnitude of overload, and NNpH environment were considered and compared to control test in air. Results showed optimum reduction in crack growth rate at low magnitude of overload in mean load pressure fluctuation. Mini striations observed on fracture surface suggest the contributions of minor cycles to crack propagation due to load interaction. Significant increase in crack growth at high magnitude of overload in NNpH environment indicates the influence of hydrogen.