Abstract
The fatigue and corrosion fatigue lives of S135 drill pipe steel were tested in air and in a simulated marine environment. The empirical equations for fatigue lives in different environments were obtained via regression analysis, and fatigue fracture mechanisms were elucidated. Results showed that an endurance limit existed in air, and fatigue cracks were initiated from or near the surface of specimens. The morphologies in air were cleavage fracture at the crack initiation zone and fatigue striations at the crack propagation zone. In the marine environment, fatigue striations were less at higher stress amplitudes, and fatigue lives were lower than that in air. Fatigue cracks were initiated from the corrosion pits on and near the surface of specimens. The morphologies were characteristic cleavage fracture at the crack initiation zone and cleavage fracture and secondary cracking at the crack propagation zone. Less fatigue striations occurred on the main fracture surface. The fracture mechanism in the marine environment can be summarized as follows: corrosion pit formation, crack initiation, crack propagation, piercing, and fracture.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
