X-ray diffraction study of microstructural changes during fatigue damage initiation in pipe steels: Role of the initial dislocation structure
| Autor: | Jacky Lesage, Edoardo Bemporad, Ilson Paranhos Pasqualino, Bianca Pinheiro, Noureddine Benseddiq |
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| Přispěvatelé: | Laboratoire de Mécanique de Lille - FRE 3723 (LML), Université de Lille, Sciences et Technologies-Ecole Centrale de Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Pinheiroa, B, Lesage, J, Pasqualino, I, Benseddiq, N, Bemporad, Edoardo |
| Rok vydání: | 2013 |
| Předmět: |
Diffraction
Materials science Dislocations 02 engineering and technology 01 natural sciences Focused ion beam Stress (mechanics) Residual stress 0103 physical sciences General Materials Science Pipe steels Fatigue Microdeformations 010302 applied physics Mechanical Engineering Metallurgy Fatigue damage initiation 021001 nanoscience & nanotechnology Condensed Matter Physics X-ray diffraction Full width at half maximum Mechanics of Materials Transmission electron microscopy X-ray crystallography Dislocation 0210 nano-technology |
| Zdroj: | Materials Science and Engineering: A Materials Science and Engineering: A, Elsevier, 2013, 580, pp.1-12. ⟨10.1016/j.msea.2013.05.042⟩ |
| ISSN: | 0921-5093 |
| DOI: | 10.1016/j.msea.2013.05.042 |
| Popis: | International audience; The present work is the second part of an ongoing study of microstructural changes during fatigue damage initiation in pipe steels [B. Pinheiro et al., Mat. Sci. Eng., A 532 (2012) 158-166]. Microdeformations and residual stresses (macrostresses) are evaluated by X-ray diffraction during alternating bending fatigue tests on samples taken from an API 5L X60 grade steel pipe. Microdeformations are evaluated from the full width at half maximum (FWHM) of the diffraction peak and residual stresses are estimated from the peak shift. Here, to understand the role of the initial dislocation structure, annealed samples are considered. As previously found for as-machined samples, the evolution of microdeformations shows three regular successive stages, but now with an increase during the first stage. The amplitude of each stage is accentuated with increasing stress amplitude, while its duration is reduced. Residual stresses show a similar trend, with stages of the same durations than those observed for FWHM, respectively. Additionally, changes in density and distribution of dislocations are observed by transmission electron microscopy combined with the technique of focused ion beam. The results are very encouraging for the development of a future indicator of fatigue damage initiation for pipe steels based on microstructural changes measured by X-ray diffraction. |
| Databáze: | OpenAIRE |
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