Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW
Polychromatic and wavelength-selective neutron transmission radiography were applied during bead-on-plate welding on 5 mm thick sheets on the face side of martensitic low transformation temperature (LTT) steel plates using gas tungsten arc welding (GTAW). The in situ visualization of austenitization...
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MDPI AG
2021-11-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/22/10886 |
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| author | Axel Griesche Beate Pfretzschner Ugur Alp Taparli Nikolay Kardjilov |
| author_facet | Axel Griesche Beate Pfretzschner Ugur Alp Taparli Nikolay Kardjilov |
| author_sort | Axel Griesche |
| collection | DOAJ |
| description | Polychromatic and wavelength-selective neutron transmission radiography were applied during bead-on-plate welding on 5 mm thick sheets on the face side of martensitic low transformation temperature (LTT) steel plates using gas tungsten arc welding (GTAW). The in situ visualization of austenitization upon welding and subsequent α’-martensite formation during cooling could be achieved with a temporal resolution of 2 s for monochromatic imaging using a single neutron wavelength and of 0.5 s for polychromatic imaging using the full spectrum of the beam (white beam). The spatial resolution achieved in the experiments was approximately 200 µm. The transmitted monochromatic neutron beam intensity at a wavelength of λ = 0.395 nm was significantly reduced during cooling below the martensitic start temperature M<sub>s</sub> since the emerging martensitic phase has a ~10% higher attenuation coefficient than the austenitic phase. Neutron imaging was significantly influenced by coherent neutron scattering caused by the thermal motion of the crystal lattice (Debye–Waller factor), resulting in a reduction in the neutron transmission by approx. 15% for monochromatic and by approx. 4% for polychromatic imaging. |
| first_indexed | 2024-03-10T05:43:01Z |
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| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T05:43:01Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-2d79ddcd16f142be9000f534181a714d2023-11-22T22:20:25ZengMDPI AGApplied Sciences2076-34172021-11-0111221088610.3390/app112210886Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAWAxel Griesche0Beate Pfretzschner1Ugur Alp Taparli2Nikolay Kardjilov3Bundesanstalt für Materialforschung und Prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyBundesanstalt für Materialforschung und Prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyBundesanstalt für Materialforschung und Prüfung (BAM), Unter den Eichen 87, 12205 Berlin, GermanyHelmholtz-Zentrum-Berlin für Materialien und Energie (HZB), Hahn-Meitner-Platz 1, 14109 Berlin, GermanyPolychromatic and wavelength-selective neutron transmission radiography were applied during bead-on-plate welding on 5 mm thick sheets on the face side of martensitic low transformation temperature (LTT) steel plates using gas tungsten arc welding (GTAW). The in situ visualization of austenitization upon welding and subsequent α’-martensite formation during cooling could be achieved with a temporal resolution of 2 s for monochromatic imaging using a single neutron wavelength and of 0.5 s for polychromatic imaging using the full spectrum of the beam (white beam). The spatial resolution achieved in the experiments was approximately 200 µm. The transmitted monochromatic neutron beam intensity at a wavelength of λ = 0.395 nm was significantly reduced during cooling below the martensitic start temperature M<sub>s</sub> since the emerging martensitic phase has a ~10% higher attenuation coefficient than the austenitic phase. Neutron imaging was significantly influenced by coherent neutron scattering caused by the thermal motion of the crystal lattice (Debye–Waller factor), resulting in a reduction in the neutron transmission by approx. 15% for monochromatic and by approx. 4% for polychromatic imaging.https://www.mdpi.com/2076-3417/11/22/10886neutron radiographyBragg-edge imaginggas tungsten arc welding (GTAW)low transformation temperature (LTT) steelaustenite-to-martensite transformationDebye–Waller factor |
| spellingShingle | Axel Griesche Beate Pfretzschner Ugur Alp Taparli Nikolay Kardjilov Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW Applied Sciences neutron radiography Bragg-edge imaging gas tungsten arc welding (GTAW) low transformation temperature (LTT) steel austenite-to-martensite transformation Debye–Waller factor |
| title | Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW |
| title_full | Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW |
| title_fullStr | Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW |
| title_full_unstemmed | Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW |
| title_short | Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW |
| title_sort | time resolved neutron bragg edge imaging a case study by observing martensitic phase formation in low temperature transformation ltt steel during gtaw |
| topic | neutron radiography Bragg-edge imaging gas tungsten arc welding (GTAW) low transformation temperature (LTT) steel austenite-to-martensite transformation Debye–Waller factor |
| url | https://www.mdpi.com/2076-3417/11/22/10886 |
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