Scale-bridging contrasting and characterization of multi-wire submerged arc welds and electron beam welds in steels
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A. Herges
has studied Materials Science at Saarland University. In 2021 he started his PhD after finishing his master thesis at the institute for functional materials from Prof. F. Mücklich.
has studied Materials Science at Saarland University. He has written his diploma thesis and his doctoral thesis in the group of Prof. F. Mücklich where he obtained a doctoral degree in 2017. As scientist, general lab manager and operator, he has taken responsibility for the group’s FIB/SEM instruments.
Abstract
For a comprehensive microstructural characterization of welds, a scale-bridging analysis of the microstructure is required. It is the only way to identify all microstructural characteristics relevant for the mechanical properties which, in turn, may cover several observation scales. The analytical methods used range from etchings for the macroscopic evaluation of the weld and heat-affected zone to the detection of so-called “local brittle zones” (LBZs) in the micrometre range. This paper will study weld joints in low-alloy steels produced by multi-wire submerged arc welding and electron beam welding. Macro and micro etching as well as electropolishing will be used for microstructural contrasting. Scanning electron microscopy will be performed to identify the finely dispersed carbon-rich secondary phase. Electron backscatter diffraction will enable the identification of so-called martensite/austenite regions (MAs) capable of acting as LBZs.
Kurzfassung
Eine vollumfängliche mikrostrukturelle Charakterisierung von Schweißnähten erfordert eine skalenübergreifende Gefügeanalyse. Nur so können alle für die mechanischen Eigenschaften relevanten Gefügemerkmale, die sich über mehrere Betrachtungsskalen erstrecken, erfasst werden. Dies reicht von Ätzungen zur makroskopischen Beurteilung von Schweißnaht und Wärmeeinflusszone bis zur Detektion sogenannter „local brittle zones“ (LBZ) im Mikrometerbereich. In der vorliegenden Arbeit werden Unterpulver- und Elektronenstrahlschweißungen niedrig legierter Stähle untersucht. Makro-, Mikroätzungen und Elektropolitur werden zur Gefügekontrastierung eingesetzt. Mittels Rasterelektronenmikroskop wird die feindisperse kohlenstoffreiche Zweitphase identifiziert. Die Elektronenrückstreubeugung ermöglicht die Identifikation sog. martensitisch-austenitischer Bereiche (MAs), die als LBZ wirken können.
About the authors
has studied Materials Science at Saarland University. In 2021 he started his PhD after finishing his master thesis at the institute for functional materials from Prof. F. Mücklich.
has studied Materials Science at Saarland University. He has written his diploma thesis and his doctoral thesis in the group of Prof. F. Mücklich where he obtained a doctoral degree in 2017. As scientist, general lab manager and operator, he has taken responsibility for the group’s FIB/SEM instruments.
5 Acknowledgements
The authors would like to thank the Federal Ministry for Economic Affairs and Climate Action (Bundesministerium für Wirtschaft und Klimaschutz, BMWK) for funding the BMWK project “Development of heavy plate for the high-performance welding of monopile foundations for the construction of offshore wind farms – High-performance plate” within which this study could be conducted. The authors would like to extend a special thanks to AG der Dillinger Hüttenwerke for providing the sample material and for the insightful discussions. The authors would also like to thank Timm Evers and Dr.-Ing. Simon Olschok for producing the electron beam welds as well as the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) and the state government of Saarland (Regierung des Saarlandes) for funding the PFIB/SEM (INST 256/510-1 FUGG) which was used for the SEM and EBSD measurements.
5 Danksagung
Die Autoren danken dem Bundesministerium für Wirtschaft und Klimaschutz für die Förderung des BMWK-Projekts „Entwicklung von Grobblechen für das Hochleistungsschweißen von Monopiles zum Bau von Wind-Offshore-Energieanlagen – HL-Blech“, in dessen Rahmen die Untersuchungen stattfinden konnten. Ein besonderer Dank für die Bereitstellung des Probenmaterials und aufschlussreichen Diskussionen geht an die AG der Dillinger Hüttenwerke. Des Weiteren gilt unser Dank Timm Evers und Dr.-Ing. Simon Olschok für die Anfertigung der Elektronenstrahlschweißungen. Die Autoren danken darüber hinaus der Deutschen Forschungsgemeinschaft und der Regierung des Saarlandes für die Förderung des PFIB/REM (INST 256/510-1 FUGG), an dem die REM- und EBSD-Messungen durchgeführt wurden.
References / Literatur
[1] Britz D.: Stahlgefüge besser verstehen – Kontrastierung, Bildanalyse und Klassifizierung niedriglegierter Stähle (2018). DOI:10.22028/D291-2802110.22028/D291-28021Search in Google Scholar
[2] Davis C. L., King J. E.: Cleavage initiation in the intercritically reheated coarse-grained heat-affected zone, Metallurgical and Materials Transactions A 25 (1994), pp. 563–573. DOI:10.1007/BF0265159810.1007/BF02651598Search in Google Scholar
[3] Kumar S., Nath S. K., Kumar V.: Effect of Single and Multiple Thermal Cycles on Microstructure and Mechanical Properties of Simulated HAZ in Low Carbon Bainitic Steel, Materials Performance and Characterization 4 (2005). DOI:10.1520/MPC2015000710.1520/MPC20150007Search in Google Scholar
[4] Bhadeshia H. K. D. H.: Bainite in Steels, 2. Auflage, IOM Communications Ltd. (2001).Search in Google Scholar
[5] Zajac S., Schwinn V., Tacke K.-H.: Characterisation and Quantification of Complex Bainitic Microstructures in High and Ultra-High Strength Linepipe Steels (2005). DOI:10.4028/0-87849-981-4.38710.4028/0-87849-981-4.387Search in Google Scholar
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Articles in the same Issue
- Contents
- Editorial
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- Structural analysis of Cu-based FeCr reinforced composites prepared by mechanical alloying
- Scale-bridging contrasting and characterization of multi-wire submerged arc welds and electron beam welds in steels
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- Failure Analysis
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- Picture of the Month
- Picture of the Month
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- News
- Meeting Dairy
- Meeting Diary
Articles in the same Issue
- Contents
- Editorial
- Editorial
- Structural analysis of Cu-based FeCr reinforced composites prepared by mechanical alloying
- Scale-bridging contrasting and characterization of multi-wire submerged arc welds and electron beam welds in steels
- Evaluation of nickel shot peening process on strength of friction stir welded AA2014-T6 aluminum alloy joints
- Failure Analysis
- How inadequate heat treatment or complete lack thereof can cause component failures
- Picture of the Month
- Picture of the Month
- News
- News
- Meeting Dairy
- Meeting Diary
