Improvement of Fatigue Strength of Welded Joints by Grain Refinement Using Laser Irradiation and Locally Carburized
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- TERATSUJI, Kazutaka
- Department of Naval Architecture and Ocean Engineering, Graduate School of Engineering, Kyushu University : Master course student
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- UCHIMURA, Tomoya
- Technical Division, School of Engineering, Kyushu University : Technician
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- MATSUDA, Kazuki
- Department of Marine Systems Engineering, Faculty of Engineering, Kyushu University : Associate Professor
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- GOTOH, Koji
- Department of Marine Systems Engineering, Faculty of Engineering, Kyushu University : Professor
Description
The purpose of this paper is to confirm fatigue strength of welded joints can be improved by grain refinement using laser irradiation and localized carburization considering corrosion and abrasion. / Comparing measured temperature history of laser irradiation with theoretical solutions of moving heat source and instantaneous line heat source, and effective temperature range of grain refinement are investigated. Only moving heat source agreed with the measured values. Maximum temperature and time required from 800 ℃ to 500 ℃ (Δt8/5) of the grain refinement region are obtained by applying moving heat source. It is reasonable based on the theory of phase transformation. / Four-point bending fatigue tests were conducted on T-joint specimens as welded, laser irradiated, and locally carburized. As a result, number of cycles to failure of the specimens which locally carburized and laser irradiated were equivalent and they are longer than that of the specimens as-welded. The main reason is locally carburized and laser irradiated had more gentler toe shapes than as-welded. However, the porosity was observed in the carburized specimen. It can affect fatigue strength, further improvement of fatigue strength was expected by eliminating it.
Journal
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- Proceedings of The 36th Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures (TEAM 2023)
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Proceedings of The 36th Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures (TEAM 2023) 63-70, 2023-10-12
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Details 詳細情報について
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- CRID
- 1050298532702988928
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- HANDLE
- 2324/7157262
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- Text Lang
- en
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- Article Type
- conference paper
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- Data Source
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- IRDB