1. Subsea Bolt Failure Analysis Using Advanced Forensics.
- Author
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Lindley, R., Li, M., Chen, W.-Y., Hudson, C., and Xiao, X.
- Subjects
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FAILURE analysis , *ELECTRON microscope techniques , *STEEL alloys , *PETROLEUM prospecting , *NATURAL gas prospecting , *FORENSIC medicine - Abstract
Resistance to environmentally assisted cracking is a key consideration in the selection of materials for subsea drilling safety critical equipment bolting applications. This paper describes several unique forensic tools used in combination to examine a safety critical bolt that failed during subsea oil and gas exploration in the Gulf of Mexico, one of several failures in a single flange. The method of examination presented here represents a new and unique toolset for examining failures in subsea bolts. The two-inch-diameter coated bolt, specified as AISI 4340 steel alloy, sheared near one of the threaded ends. The sheared bolt end was removed and cut approximately in half to examine microscopic cracks. Scanning electron microscopy techniques were utilized to examine the flat, cut face of the bolt interior. The sample and individual small sections were examined at the Advanced Photon Source at Argonne National Laboratory using high-energy synchrotron X-rays with energy levels up to 100 keV. The X-ray examinations produced a three-dimensional picture of the sample. Based on the results and discussions, design recommendations were made for increased corrosion resistance in subsea environments. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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