Marco and Microscopic Observations of Fatigue Crack Growth Behavior in API 2W Gr. 50 Steel Joints |
Sohn Hye-Jeong,Kim Seon-Jin |
Department of Mechanical Design Engineering Pukyong National University,Department of Mechanical and Automotive Engineering Pukyong National University |
API 2W Gr. 50 강재 용접부의 피로균열전파거동의 거시적 및 미시적 관찰 |
손혜정,김선진 |
부경대학교 대학원 기계설계공학과,부경대학교 기계자동차공학과 |
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© 2012 The Korean Society of Ocean Engineers
Open access / Under a Creative Commons License
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Keywords:
Flux Core Arc Welding, Fatigue Crack Growth, Constant Amplitude Cyclic Loading, Scanning Electron Microscopy |
핵심용어:
플럭스코어드아크용접, 피로균열전파, 일정진폭반복 하중, 주사전자현미경 |
Abstract |
It is well known that a considerable amount of scatter is shown in experimental results relating to fatigue crack growth even under identical and constant amplitude cyclic loading conditions. Moreover, flux cored arc welding (FCAW) is a common method used to join thick plates such as the structural members of large scale offshore structures and very large container ships. The objective of this study was to investigate the macro- and microscopic observations of the fatigue crack growth (FCG) behavior of the FCAWed API 2W Gr. 50 steel joints typically applied for offshore structures. In order to clearly understand the randomness of the fatigue crack growth behavior in the materials of three different zones, the weld metal (WM), heat affected zone (HAZ), and base metal (BM), experimental fatigue crack growth tests for each of five specimens were performed on ASTM standard compact tension (CT) specimens under constant amplitude cyclic loading. Special focus was placed on the fatigued fracture surfaces. As a result, a different behavior was observed at the macro-level, depending on the type of material property: BM, HAZ, or WM. The variability in the fatigue crack growth rate for WM was higher than that of BM and HAZ. |
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