Failure analysis of a failed anchor chain link
The failure of a metal chain link with stud during an anchoring operation of a ship is examined. Visual observation, optical and scanning electron microscopy analyses of the fracture surfaces in combination with hardness and tensile tests are used to establish the cause of failure. The chemical elem...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/142794 |
| _version_ | 1811677722876837888 |
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| author | Idapalapati, Sridhar Akisanya, Alfred R. Loh, Kelvin K. M. Yeo, Stedston |
| author2 | School of Mechanical and Aerospace Engineering |
| author_facet | School of Mechanical and Aerospace Engineering Idapalapati, Sridhar Akisanya, Alfred R. Loh, Kelvin K. M. Yeo, Stedston |
| author_sort | Idapalapati, Sridhar |
| collection | NTU |
| description | The failure of a metal chain link with stud during an anchoring operation of a ship is examined. Visual observation, optical and scanning electron microscopy analyses of the fracture surfaces in combination with hardness and tensile tests are used to establish the cause of failure. The chemical element composition, tensile strength, yield strength and elongation of the base metal of the chain link are within the recommended design values. However, cross-sectional microstructure examination revealed that the fracture occurred along the flash butt weld and initiated from a pre-existing edge radial crack on the outer surface which had been painted over. The presence of inclusions near the outer surface, decarburized boundaries of the inclusions and a decarburized thin strip along the entire weldment had resulted in weldment strength reduction and subsequent initiation of the surface crack. The main cause of the chain link failure is improper flash welding and heat treatment resulting in localised carbide segregations and embrittlement, leading to initiation of surface crack and consequent overload of the remaining net-section area of the chain. There was no evidence of fatigue crack growth. Better inspection and maintenance would have led to early detection of the surface crack during any the periodic non-destructive testing. |
| first_indexed | 2024-10-01T02:41:53Z |
| format | Journal Article |
| id | ntu-10356/142794 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:41:53Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | ntu-10356/1427942020-06-30T09:21:53Z Failure analysis of a failed anchor chain link Idapalapati, Sridhar Akisanya, Alfred R. Loh, Kelvin K. M. Yeo, Stedston School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Anchor Chain Link Failure Analysis The failure of a metal chain link with stud during an anchoring operation of a ship is examined. Visual observation, optical and scanning electron microscopy analyses of the fracture surfaces in combination with hardness and tensile tests are used to establish the cause of failure. The chemical element composition, tensile strength, yield strength and elongation of the base metal of the chain link are within the recommended design values. However, cross-sectional microstructure examination revealed that the fracture occurred along the flash butt weld and initiated from a pre-existing edge radial crack on the outer surface which had been painted over. The presence of inclusions near the outer surface, decarburized boundaries of the inclusions and a decarburized thin strip along the entire weldment had resulted in weldment strength reduction and subsequent initiation of the surface crack. The main cause of the chain link failure is improper flash welding and heat treatment resulting in localised carbide segregations and embrittlement, leading to initiation of surface crack and consequent overload of the remaining net-section area of the chain. There was no evidence of fatigue crack growth. Better inspection and maintenance would have led to early detection of the surface crack during any the periodic non-destructive testing. 2020-06-30T09:21:53Z 2020-06-30T09:21:53Z 2018 Journal Article Idapalapati, S., Akisanya, A. R., Loh, K. K. M., & Yeo, S. (2018). Failure analysis of a failed anchor chain link. Engineering Failure Analysis, 89, 258-270. doi:10.1016/j.engfailanal.2018.03.007 1350-6307 https://hdl.handle.net/10356/142794 10.1016/j.engfailanal.2018.03.007 2-s2.0-85043530192 89 258 270 en Engineering Failure Analysis © 2018 Elsevier Ltd. All rights reserved. |
| spellingShingle | Engineering::Mechanical engineering Anchor Chain Link Failure Analysis Idapalapati, Sridhar Akisanya, Alfred R. Loh, Kelvin K. M. Yeo, Stedston Failure analysis of a failed anchor chain link |
| title | Failure analysis of a failed anchor chain link |
| title_full | Failure analysis of a failed anchor chain link |
| title_fullStr | Failure analysis of a failed anchor chain link |
| title_full_unstemmed | Failure analysis of a failed anchor chain link |
| title_short | Failure analysis of a failed anchor chain link |
| title_sort | failure analysis of a failed anchor chain link |
| topic | Engineering::Mechanical engineering Anchor Chain Link Failure Analysis |
| url | https://hdl.handle.net/10356/142794 |
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