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    <id>51587</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
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    <title language="eng">Influence of welding stresses on relaxation cracking during heat treatment of a creep-resistant 13CrMoV steel, Part III</title>
    <abstract language="eng">Efficiency and flexibility are currently a major concern in the design of modern power plants and chemical processing facilities. The high requirements for economic profitability and in particular climate change neutrality are driving this development. Consequently, plant equipment and chemical reactor components are designed for higher operating pressure and temperature. Creep-resistant CrMo steels had been used as constructional materials for decades but came to operational limitations, for example the resistance against so-called high-temperature hydrogen attack in petrochemical reactors. For that purpose, 20 years ago V-modified CrMo steels had been developed for use in the petrochemical industry due to their very good creep-strength and hydrogen pressure resistance at elevated temperatures enabling long service life of the respective components. For example, the 13CrMoV9-10 steel is applicable for process temperatures of up to 482 °C and hydrogen pressures of up to 34.5 MPa.&#13;
Due to the large dimensions and wall thickness of the reactors (wall thickness up to 475 mm) and the special alloy concept, reliable weld manufacturing of the components is extremely challenging. First, low toughness and high strength of the weld joint in the as-welded condition are critical regarding weld cracking. High welding residual stresses are the result of the highly restrained shrinkage of the component welds. For this purpose, the entire component must be subjected to Post-Weld Heat Treatment (PWHT) after completion of the welding operation. The aim is to increase the toughness of the weld joints as well as to reduce the welding induced residual stresses. Before and during PWHT, extreme caution is required to prevent cracking. Unfortunately, V-modified CrMo steels possess an increased susceptibility to cracking during stress relaxation the so-called stress relief cracking (SRC).&#13;
Available literature studies have largely focused on thermal and metallurgical factors. However, little attention has been paid on the influence of the welding procedure on crack formation during PWHT considering actual manufacturing conditions. For that reason, we investigated in our previous studies (part I and II), the influence of heat control on the mechanical properties by simulating actual manufacturing conditions prevailing during the construction of petrochemical reactors using a special 3D- acting testing facility. The focus of part I was put on the influence of the welding heat control on mechanical stresses and the effect on cracking during PWHT. Part II was mainly dedicated to the metallurgical causes of SRC during PWHT and the interaction with the occurring mechanical stresses. It could be shown that not only high welding-induced stresses due to increased weld heat input cause higher susceptibility for SRC formation. It was further intensified by an altered precipitation behaviour in presence of mechanical stresses that are caused by the component related restraint. The present part III shows how residual stresses, which are present in such welded components and significantly influence the crack formation, can be transferred to the laboratory scale. As a result, the effect on the residual stresses on the SRC behaviour can be evaluated on simplified small-scale specimens instead of expensive mock-ups. For this purpose, experiments with test set-ups at different scales and under different rigidity conditions were designed and carried out.</abstract>
    <enrichment key="eventName">IIW Annual Assembly, Meeting of Commission II-A</enrichment>
    <enrichment key="eventPlace">Online meeting</enrichment>
    <enrichment key="eventStart">20.07.2020</enrichment>
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    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Creep-resistant steel</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stresses</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Post weld heat treatment</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Stress relief cracking</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="institutes" number="">9.0 Abteilungsleitung und andere</collection>
  </doc>
  <doc>
    <id>28920</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Einfluss der Wärmeführung auf den Eigenspannungszustand in Schweißkonstrukionen aus hochfesten Feinkornbaustählen</title>
    <parentTitle language="deu">MDDK Wintersemester 2012/13</parentTitle>
    <identifier type="old">31814</identifier>
    <enrichment key="eventName">MDDK Wintersemester 2012/13</enrichment>
    <enrichment key="eventPlace">Magdeburg, Germany</enrichment>
    <enrichment key="eventStart">2013-01-24</enrichment>
    <enrichment key="eventEnd">2013-01-24</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <collection role="fulltextaccess" number="">Weder Datei noch physisches Exemplar vorhanden ("No Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>28919</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Einfluss der Wärmeführung auf die Eigenbeanspruchung in Schweißkonstruktionen aus hochfesten Feinkornbaustählen</title>
    <parentTitle language="deu">MDDK Sommersemester 2013</parentTitle>
    <identifier type="old">31813</identifier>
    <enrichment key="eventName">MDDK Sommersemester 2013</enrichment>
    <enrichment key="eventPlace">Magdeburg, Germany</enrichment>
    <enrichment key="eventStart">2013-07-04</enrichment>
    <enrichment key="eventEnd">2013-07-04</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <collection role="fulltextaccess" number="">Weder Datei noch physisches Exemplar vorhanden ("No Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>44267</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Division 9.4 – Weld Mechanics, Key aspects of component welding applying higher-strength fine-grained structural steels</title>
    <abstract language="eng">Presentation of the work of division 9.4 with focus on the Key aspects of component welding applying higher-strength fine-grained structural steels. The increased application of higher-strength steels and filler materials necessitates a more profound understanding of the interactions between the welding process, the heat input, the cooling conditions and the resulting metallurgical processes in the weld and its surroundings. Strategies, which help to improve the strength properties and life-time of welded structures to such an extent that the utilisation of higher-strength materials can be justified and their lightweight construction potential can thus be exploited to the full, can only be derived from the interaction between all the influencing factors. Examples of a few investigations on welded joints between higher-strength fine-grained structural steels with regard to the interactions between the main variables influencing the cold cracking are presented.</abstract>
    <enrichment key="eventName">MIIT Workshop</enrichment>
    <enrichment key="eventPlace">BAM, Berlin, Germany</enrichment>
    <enrichment key="eventStart">28.11.2017</enrichment>
    <enrichment key="eventEnd">28.11.2017</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stresses</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Higher-strength steels</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cold cracking</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Heat control</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>45623</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Welding Stress Control in High-strength Steel Components Using Adapted Heat Control Concepts</title>
    <abstract language="eng">High-strength steels are increasingly applied in modern steel constructions to meet today’s lightweight requirements. Welding of these steels demands a profound knowledge of the interactions between the welding process, cooling conditions, heat input and the resulting metallurgical occurrences in the weld and its vicinity. Additionally, welding stresses may be detrimental for the safety and performance of high-strength steel component welds during fabrication and service, especially due to the high yield ratio. For a development of strategies to adjust welding heat control, all these effects should be considered, to reach a complete exploitation of the high-strength steel potential. In recent researches at BAM, multilayer GMAW experiments were performed with high-strength steels, in which cooling conditions and resulting microstructure were analysed for varied heat control parameters. The application of a unique 3d-operating testing facility and X-ray diffraction measurements allowed the analysis of local stresses in the weld while welding and cooling under component relevant shrinkage restraints. As a result, correlations between material behaviour, welding and cooling condition and the arising multi-axial stresses and forces were found. Based on this study, statements for the development of adapted heat control concepts were derived, which are presented by means of specific analysis examples.</abstract>
    <enrichment key="eventName">71st IIW Annual Assembly and International Conference: Commission II-A</enrichment>
    <enrichment key="eventPlace">Nusa Dua, Bali, Indonesia</enrichment>
    <enrichment key="eventStart">15.07.2018</enrichment>
    <enrichment key="eventEnd">20.07.2018</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stresses</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>GMA Welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Restraint</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High-strength steels</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Process parameters</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>46611</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Auswirkung der Nahtkonfiguration und des modifizierten Sprühlichtbogens auf die Bauteilbeanspruchungen in hochfesten Schweißverbindungen.</title>
    <abstract language="deu">In modernen Stahlkonstruktionen werden immer häufiger hochfeste Feinkornbaustähle erfolgreich eingesetzt. Dies resultiert aus dem aktuellen Bestreben, leichte Komponenten zu fertigen und damit die Energie- und Ressourceneffizienz zu steigern. Die Herausforderungen an die Auslegung und Herstellung geschweißter Bauteile nimmt jedoch mit steigenden Festigkeiten und abnehmenden Dehnungsreserven der eingesetzten Werkstoffe zu. So können hohe Schweißeigenspannungen die Beanspruchbarkeit und Bauteilsicherheit kritisch herabsetzen. Untersuchungen zeigten bereits deutliche Einflüsse von Werkstoff, Wärmeführung sowie Schweißprozessparametern und der um-gebenden Konstruktion der Schweißnaht auf den Beanspruchungszustand geschweißter Bauteile. Der Einsatz moderner modifizierter Sprühlichtbogenprozesse (mod.SLB) gestattet in diesen Zusammenhang neben den bekannten wirtschaftlichen Vorteilen das Schweißen einer deutlich schmaleren Nahtgeometrie. Aufgrund des resultierenden reduzierten Gesamtwärmeeintrages sind deutlich geringere schweißbedingte Beanspruchungen und eine höhere Beanspruchbarkeit hochfester Schweißkonstruktionen erreichbar. Unter Nutzung spezieller Prüfanlagen konnten mehrlagige Schweißexperimente zur Analyse des Einflusses der Nahtgeometrie auf die Eigenspannungsausbildung und Gesamtbeanspruchung hochfester Schweißverbindungen bei bauteilähnlichen Einspannbedingungen durchgeführt werden. Für die reduzierten Nahtvolumina zeigte sich eine signifikante Absenkung des Beanspruchungsniveaus während des Schweißens und nach der Abkühlung.</abstract>
    <enrichment key="eventName">DVS Congress Große Schweißtechnische Tagung 2017</enrichment>
    <enrichment key="eventPlace">Düsseldorf, Germany</enrichment>
    <enrichment key="eventStart">26.09.2017</enrichment>
    <enrichment key="eventEnd">29.09.2017</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Eigenspannungen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>MAG-Schweißen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Hochfeste Feinkornbaustähle</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Bauteilprüfung</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>46607</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">In-situ determination of critical welding stresses during assembly of thick-walled components made of high-strength steel</title>
    <abstract language="eng">The performance and safety of welded high-strength low-alloyed steel (HSLA) components are substantially affected by the stresses occurring during and after welding fabrication, especially if welding shrinkage and distortion are severely restrained. The surrounding structure of the whole component affects loads in the far-field superimposing with welding stresses in the near-field of the weld. In this study a unique testing facility was used to restrain shrinkage and bending while analyse multiaxial far-field loads (max. 2 MN) during assembly of thick-walled component. A novel approach for the assessment of the in-situ-measured far-field data in combination with the actual weld geometry was elaborated. For the first time, analyses of the global bending moments of restrained welds based on the neutral axis of the actual weld load bearing section were achieved. Hence, far-field measurements offered the possibility to determine critical near-field stresses of the weld crosssections for the entire joining process. This work presents the approach for far-to-near field in-situ determination of stresses in detail for the 2-MN-testing system based on an extensive experimental work on HSLA steel welds, which demonstrates sources and consequences of these high local welding stresses. Thus, it was clarified, why the first weld beads are crucial regarding welding stresses and cold cracking, which is well known, but has never been measured so far. Accompanying analyses using X-ray diffraction (XRD) after welding show effects on local residual stress distributions. These analyses indicated viable prospects for stress reduction during assembly of thick-walled HSLA steel components.</abstract>
    <enrichment key="eventName">European Conference on Residual Stresses 2018 - ECRS-10</enrichment>
    <enrichment key="eventPlace">Leuven, Belgium</enrichment>
    <enrichment key="eventStart">11.09.2018</enrichment>
    <enrichment key="eventEnd">14.09.2018</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stress</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Large-scale test</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>X-ray diffraction</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>HSLA steel</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>47718</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Optimierung schweißbedingter Beanspruchungen und Eigenschaften höherfester Verbindungen mittels Wärmeführung</title>
    <abstract language="deu">Der zunehmende Bedarf an hochfesten Feinkornbaustählen in modernen Schweißkonstruktionen, in einer deutlich wachsenden Anzahl von Branchen wie dem Hoch-, Anlagen- und Kranbau, führte in den letzten Jahren zur Entwicklung zahlreicher Grund- und Zusatzwerkstoffe. Neben der Erreichung anforderungsgerechter mechanischer Eigenschaften wird die wirtschaftliche Verarbeitung dieser Güten durch hohe Sicherheitsanforderungen an die Schweißnaht bestimmt. Hohe Zugeigenspannungen in der Schweißverbindung können die Beanspruchbarkeit und Sicherheit eines geschweißten Bauteils wesentlich reduzieren. Insbesondere bei einer hohen konstruktiven Schrumpfbehinderung können die Beanspruchungen auch schon während der Fertigung ein risskritisches Niveau erreichen.&#13;
Mittels geeigneten Wärmeführungen beim Schweißen und der adäquaten Auswahl von Schweißprozess und Zusatzwerkstoffen ist sowohl eine Minimierung der sich lokal in der Naht bildenden Zugeigenspannungen als auch der globalen infolge von Abstützeffekten auftretenden Reaktionsspannungen und -momente erzielbar. Im Rahmen zweier AiF-Forschungsvorhaben IGF.-Nr. 17267 N und 17978 N wurden verschiedene experimentelle Beanspruchungsanalysen durchgeführt, um den Schweißprozess hinsichtlich der resultierenden schweißbedingten Beanspruchungen zu untersuchen. Hierfür war es erforderlich, die Steifigkeitsverhältnisse so wie sie beim Schweißen realer Bauteilstrukturen auftreten, auf Schweißexperimente im Labor zu übertragen.&#13;
Dazu wurde bspw. eine an der BAM eigens entwickelte Prüfanlage eingesetzt, mit der die mehraxialen Belastungen analysiert wurden, die mit bis zu 2 MN beim Vorwärmen, Schweißen und Abkühlen auftreten. Die Schweißeigenspannungen wurden mittels Röntgendiffraktometrie bestimmt. Zwar zeigten sich für niedrige Arbeitstemperaturen beim Schweißen ein signifikant reduziertes Gesamtbeanspruchungsniveau nach der Abkühlung der gesamten Schweißnaht. Die langen Abkühlphasen während der mehrlagigen schweißtechnischen Fertigung führen jedoch speziell bei den ersten Schweißraupen zu sehr hohen Reaktionsspannungen. Dabei erwiesen sich schmalere Nahtfugen verbunden mit dem Einsatz modifizierter Schweißprozesse und der Einsatz dehnfähiger Schweißzusätze für das Wurzelschweißen als geeignete Mittel, um eine deutliche Absenkung des Beanspruchungsniveaus beim Schweißen unter Schrumpfbehinderung zu erreichen. Ferner ist damit eine weitere wesentliche Reduzierung der Gesamtbeanspruchung und insbesondere der Zugeigenspannungen in der WEZ möglich. Mithilfe dieser Erkenntnisse ist die Optimierung der schweißbedingten Beanspruchungen unter Nutzung einer adaptierten Wärmeführung zur verbesserten Ausnutzung des Festigkeitspotentials höherfester Feinkornbaustähle erreichbar.</abstract>
    <enrichment key="eventName">Forschungsseminar, TU Chemnitz</enrichment>
    <enrichment key="eventPlace">Chemnitz, Germany</enrichment>
    <enrichment key="eventStart">07.06.2017</enrichment>
    <enrichment key="eventEnd">08.06.2017</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Bauteilprüfung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Eigenspannungen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Hochfeste Feinkornbaustähle</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>MAG-Schweißen</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>61933</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Beanspruchungsgerechte Reparatur von Schweiß-Verbindungen bei der Fertigung von Bauteilen aus hochfesten Feinkornbaustählen (FOSTA P1311, IGF 20162 N)</title>
    <abstract language="deu">Zunehmende Anlagengrößen im Bereich Windenergie erfordern hochfeste Stähle, um vorhandene Leichtbaupotenziale auszuschöpfen. An die schweißtechnische Verarbeitung dieser Stahlgüten werden hohe Anforderungen gestellt. Bei mittels zerstörungsfreier Prüfung festgestellten Fehlstellen empfehlen geltende Verarbeitungsrichtlinien lokales Ausfugen und Reparaturschweißen. Degradationen der speziellen hochfesten Gefüge und Werkstoffeigenschaften sowie hohe Schrumpfbehinderungen der umliegenden Struktur ausgefugter Bereiche erhöhen das Risiko erneuter Schweißdefekte, insbesondere durch Überlagerung von globalen und lokalen schweißbedingten Eigenspannungen nach dem Reparaturschweißen. Fehlende Informationen über geeignete Reparaturkonzepte in den Regelwerken können dazu führen, dass reparaturbedingte Beanspruchungen unzureichend berücksichtigt werden. Das FOSTA-Vorhaben P1311 (IGF20162N) fokussiert das Reparaturschweißen zweier hochfester Stähle: S500MLO für Offshore- Anwendungen und S960QL für Errichterstrukturen, z. B. Mobilkräne. Simulationen von Einspannbedingungen und Bauteilanalysen sowie Versuche mit anwendungs- bzw. realitätsnahen Bauteilstrukturen ließen sich auftretende schweißbedingte Beanspruchungen mittels Röntgendiffraktometrie (XRD), Härtemessungen und metallografischer Untersuchungen ermitteln. In diesem Beitrag steht die Interaktion aus Wärmeführung und konstruktiver Steifigkeit als Einfluss auf die entstehenden Beanspruchungen bei einfacher und mehrfacher Reparatur im Vordergrund. Die Ergebnisse zeigen, dass sich risskritische Eigenspannungen durch adaptierte Wärmeführungskonzepte vermeiden lassen, und dass dies eine Grundlage für Verarbeitungsempfehlungen und für normative Vorgaben ist. Dies kann insbesondere kleine und mittelständischen Unternehmen bei einer wirtschaftlichen, beanspruchungsgerechten Reparatur hochfester geschweißter Bauteilen unterstützen.</abstract>
    <enrichment key="eventName">DVS Innovationstage 2024</enrichment>
    <enrichment key="eventPlace">Düsseldorf, Germany</enrichment>
    <enrichment key="eventStart">10.04.2024</enrichment>
    <enrichment key="eventEnd">11.04.2024</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
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    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <author>Levin Reichel</author>
    <author>Thomas Kannengießer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Reparaturschweißen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Thermisches Ausfugen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Sprühlichtbogen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Offshore</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
  </doc>
  <doc>
    <id>61927</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Evaluation of the wear protection of modified Nimocrsi alloy and machinability using ultrasonic-assisted milling</title>
    <abstract language="eng">The targets for reducing CO2 emissions are closely linked to the development of highly efficient and economical steel components in plant, process and power plant technology, which require wear protection coatings tailored to the application and steel material for high combined corrosive, tribological, thermal and mechanical stresses. There is a growing demand in industry for defined functional surfaces of high quality for these coatings. Milling is a standard process for finish machining. The desired properties of wear resistant alloys imply significant challenges for the milling process due to high tool wear and surface defects. Besides the hardness of the coating materials, especially due to the precipitations, inhomogeneous, anisotropic weld structures of the claddings lead to further deteriorations of milling processes due to unstable milling conditions and process forces.&#13;
A joint project of BAM and ISAF of TU Clausthal (Fosta P1550/IGF 21959 N) investigates the optimization of these challenging machining conditions by means of alloy modifications of the welding powder for plasma transferred arc cladding, without reducing the wear protection potential and using ultrasonic assisted milling process.</abstract>
    <enrichment key="eventName">6th European Symposium on Friction, Wear and Wear Protection</enrichment>
    <enrichment key="eventPlace">Oberhof, Germany</enrichment>
    <enrichment key="eventStart">26.02.2024</enrichment>
    <enrichment key="eventEnd">27.02.2024</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic assisted milling</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Surface integrity</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
  </doc>
  <doc>
    <id>53328</id>
    <completedYear/>
    <publishedYear>2021</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Process-related influences and correlations in wire arc additive manufacturing of high-strength steels</title>
    <abstract language="eng">High-strength fine-grained structural steels have great potential for weight-optimized, efficient structures in many modern steel applications. Further advances in efficiency can be achieved through additive manufacturing and bionic design. Commercial high-strength filler materials for wire arc additive manufacturing (WAAM) are already provided by the consumable producers. Today, application would be strictly limited due to absence of quantitative findings or any guidelines for the industry regarding welding-related stresses and component safety during manufacturing and service. Hence, process- and material-related influences and design-related restraint conditions associated with formation of residual stresses and cold cracking risk are investigated. The aim is the accessibility of special WAAM self-restraining cold cracking tests and easy applicable processing recommendations, enabling an economical, fit-for-purpose and crack-safe WAAM of high-strength steels. This first study focuses on determination of interactions between WAAM process parameters, resulting layer geometry, microstructure and residual stresses, analyzed via X-ray diffraction. Defined reference specimens are automated welded using a special WAAM solid wire (yield strength &gt;820 MPa). Geometric properties can be specifically adjusted by wire feed and welding speed, but cannot be varied arbitrarily, since a high heat input causes local overheating, inadmissible changes of microstructure and mechanical properties, defects and comparable high tensile residual stresses.</abstract>
    <enrichment key="eventName">22. Werkstofftechnischen Kolloquium der TU Chemnitz</enrichment>
    <enrichment key="eventPlace">Online meeting</enrichment>
    <enrichment key="eventStart">24.03.2021</enrichment>
    <enrichment key="opus.source">publish</enrichment>
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    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Additive Manufacturing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High-strength steel</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stresses</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
  </doc>
  <doc>
    <id>59261</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Residual stress formation in DED-arc manufactured high strength steel components</title>
    <abstract language="eng">Additive manufacturing (AM) processes enable the efficient production of advanced constructions. New developments in topology optimization are leading to weight-optimized designs of increasing complexity. Direct energy deposition processes (DED) such as wire and arc-based additive manufacturing are an important method of additive manufacturing. The wire filler metals enable a wide range of materials, while the arc process provides a high deposition rate compared to laser and powder-based processes. Combined with the use of high-strength steels, the thickness of walls or components can be significantly reduced in the context of lightweight construction, which results in significant savings in energy, costs, time and resources. Suitable high-strength steel filler metals are commercially available for DED-arc AM processes. However, guidelines and quantitative knowledge about welding stresses and cold cracking issues during component production and service are lacking. This limits the industrial application considerably. In a joint project of BAM and Chemnitz University of Technology, the main influences and complex interactions of material, production process, design and processing steps on the residual stress level are investigated. The aim is to develop processing recommendations and a cold cracking test for economical processing and stress-related design of high-strength steels with DED-arc. This study focuses on residual stress analysis by neutron diffraction (ND) and X-ray diffraction (XRD) on defined test specimens. The ND analysis were performed at the Paul Scherrer Institute- Villigen, Switzerland (PSI) and the XRD analysis at BAM. The study shows a quantitative and qualitative comparison of the residual stress magnitudes and distribution between the component bulk (ND) and surface (XRD) analyses. The ND analysis reveals that in DED-arc AM walls the residual stresses dominate in the direction of welding and are negligibly small in each case transverse to the direction of welding. The topology of the analyzed residual stresses shows almost identical residual stress maps compared to XRD. In addition, the residual stresses are significantly influenced by the solid phase transformation of the material due to low cooling times and less post heat treatment cycles of following AM layers  in the area of the top layer.</abstract>
    <enrichment key="eventName">IIW Intermediate Meeting 2023 CII and CIX</enrichment>
    <enrichment key="eventPlace">Munich, Germany</enrichment>
    <enrichment key="eventStart">06.03.2023</enrichment>
    <enrichment key="eventEnd">09.03.2023</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>WAAM</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual Stresses</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High-strength Steels</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Microstructure</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cold cracking safety</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Wind energy</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
  </doc>
  <doc>
    <id>61934</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Fertigungsbedingte Beanspruchungen und Kaltrisssicherheit in generativ gefertigten Bauteilen aus hochfesten Feinkornbaustählen</title>
    <abstract language="deu">Additive Fertigungsverfahren wie das Direct Energy Deposition-Arc (DED-Arc) oder Wire Arc Additive Manufacturing (WAAM) ermöglichen die effiziente Herstellung gewichtsoptimierter, endkonturnaher Bauteile im modernen Stahlbau. Steigerungen der Effizienz können durch den Einsatz hochfester Stähle erreicht werden, insbesondere durch Verringerung von Wandstärken und Bauteilgewicht sowie signifikante Einsparung von Kosten, Zeit und Ressourcen. DED-Arc Schweißzusatzwerkstoffe sind bereits auf dem Markt verfügbar, allerdings fehlen Richtlinien und quantitative Kenntnisse über die schweißbedingte Beanspruchung während der Fertigung und im Betrieb, welche den industriellen Einsatz stark limitieren. In einem gemeinsamen Projekt der BAM und der Technischen Universität Chemnitz wurden die wesentlichen Einflüsse und komplexen Wechselwirkungen von Werkstoff, Fertigungsverfahren, Konstruktion und Bearbeitungsschritten auf die Eigenspannungen untersucht. Ziel war es, den stahlverarbeitenden Anwendern, insbesondere KMU, eine risssichere und beanspruchungsgerechte Herstellung und Modifizierung von Bauteilen und Halbzeugen aus hochfesten Feinkornbaustahl unter Verwendung MSG-basierter generativer Verfahren zu ermöglichen.</abstract>
    <enrichment key="eventName">DVS Innovationstage 2024</enrichment>
    <enrichment key="eventPlace">Düsseldorf, Germany</enrichment>
    <enrichment key="eventStart">10.04.2024</enrichment>
    <enrichment key="eventEnd">11.04.2024</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Karsten Wandtke</author>
    <author>Dirk Schröpfer</author>
    <author>Thomas Kannengießer</author>
    <author>Ronny Scharf-Wildenhain</author>
    <author>Andre Hälsig</author>
    <author>Arne Kromm</author>
    <author>J. Hensel</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Feinkornbaustähle</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Additive Fertigung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Kaltrisssicherheit</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Direct Energy Deposition-Arc (DED-Arc), Wire Arc Additive Manufacturing (WAAM)</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
  </doc>
  <doc>
    <id>65051</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Influence of Ultrasonic-Assisted Milling on Surface Integrity of Additively Manufactured Components Using DED-Arc/GMAW</title>
    <abstract language="eng">Additive manufacturing (AM) is increasingly used for producing complex metallic com-ponents. Subsequent machining is essential to achieve final geometries and surface conditions. The resulting surface integrity, particularly the near-surface residual stress state, plays a crucial role in component performance and fatigue life. This study inves-tigates the potential of ultrasonic-assisted milling (USAM), a hybrid machining process, to improve surface integrity and machinability compared to conventional milling (CM). Three materials were investigated, two difficult-to-cut materials CoCr26Ni9Mo5W and FeNi36 and a low-alloy steel S355J2C. The CoCr26Ni9Mo5W and FeNi36 were addi-tively manufactured via DED-Arc and then machined with varying cutting speeds and feed rates within a Design of Experiments. USAM exhibited enhanced machinability and surface integrity, particularly at low cutting speeds, by reducing cutting forces up to 40% and shifting near-surface residual stresses from tensile to compressive. For S355J2C, USAM reduced cutting forces by approximately 45% and induced surface-near compressive residual stresses up to approximately -700 MPa, leading to a 11% higher fatigue strength compared to CM. These findings highlight the advantages of ultrasonic assistance in post-AM machining, offering enhanced fatigue performance and surface quality for various metallic materials.</abstract>
    <enrichment key="eventName">4th International Conference on Advanced Joining Processes 2025</enrichment>
    <enrichment key="eventPlace">Coimbra, Portugal</enrichment>
    <enrichment key="eventStart">16.10.2025</enrichment>
    <enrichment key="eventEnd">17.10.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic-assisted milling</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Additive manufacturing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Surface integrity</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fatigue strength</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stress</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
  </doc>
  <doc>
    <id>65048</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Influence of Substrate Design on Properties and Residual Stresses in Hybrid AM/DED-Arc of High-Strength Steels</title>
    <abstract language="eng">High-strength, fine-grained structural steels are increasingly used in modern steel construction to meet economic and environmental demands through lightweight design and reduced material usage. Additive manufacturing (AM), in particularly direct energy deposition with gas metal arc welding (DED-Arc), offers significant advantages in flex-ibility, production speed, and cost efficiency. In hybrid AM, conventionally manufac-tured parts are extended or modified using AM processes. Welding-induced residual stresses, especially in the transition area, pose challenges to structural integrity. This study investigates the influence of substrate design and thermal pretreatment on the residual stress state of hybrid AM components made from base material steel S690QL and a welding filler, a modified solid wire G79. Two substrate geometries (I- and T-substrate) are analysed, which are additively and conventionally manufactured, re-spectively. Results show that substrate geometry significantly affects local residual stresses, microstructure and hardness, particularly in the transition are. The findings contribute to a better understanding of the evolution of welding stresses in hybrid AM components to achieve reliable, crack-resistant and economic high-strength steel structures.</abstract>
    <enrichment key="eventName">4th International Conference on Advanced Joining Processes 2025</enrichment>
    <enrichment key="eventPlace">Coimbra, Portugal</enrichment>
    <enrichment key="eventStart">16.10.2025</enrichment>
    <enrichment key="eventEnd">17.10.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
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    <enrichment key="opus.doi.autoCreate">false</enrichment>
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    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DED-Arc</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stress</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Hybrid additive manufacturing</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
  </doc>
  <doc>
    <id>65260</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Bericht zum Fortschritt des laufenden Projekts: „Praktikable Prüfung geschweißter Ferngasleitungen aus niedrig-legierten Stählen für den sicheren Transport von Wasserstoff“</title>
    <abstract language="deu">Das Vorhaben untersucht, wie geschweißte Ferngasleitungen aus niedriglegierten und höherfesten Stählen sicher für den Transport von Wasserstoff genutzt werden können. Im Fokus steht, in welchem Maß Wasserstoff unter verschiedenen Druck-, Temperatur- und Gaszusammensetzungen in Werkstoffe und Schweißverbindungen eindringt, deren Duktilität mindert und sprödbrüchiges Versagen verursachen kann. Dafür wird die Prüftechnik der Hohlzugproben in Kombination mit Slow-Strain-Rate-Tests weiterentwickelt, um reale Beanspruchungsbedingungen abzubilden und wirtschaftliche, praxisnahe Prüfungen zu ermöglichen. Untersucht werden insbesondere Schweißnahtgefüge, deren Interaktion, zyklische Belastungen sowie die Übertragbarkeit der Laborergebnisse auf reale Komponenten. Ziel ist ein praktikables Bewertungs- und Qualifizierungskonzept, das die H2-Readiness bestehender und neuer Rohrleitungen beschleunigt und in Normung und Industrieanwendung überführt werden kann.</abstract>
    <enrichment key="eventName">Herbstsitzung des Fachausschuss "FA 1 Schweißmetallurgie und Werkstoffverhalten"</enrichment>
    <enrichment key="eventPlace">Düsseldorf, Germany</enrichment>
    <enrichment key="eventStart">06.11.2025</enrichment>
    <enrichment key="eventEnd">06.11.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Wasserstoffversprödung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Hohlzugproben</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Slow-Strain Rate Test</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Schweißnahtgefüge</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Wasserstoff</collection>
  </doc>
  <doc>
    <id>65245</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Begrüßung und Vorstellung der BAMund des Fachbereichs 9.2 - Zentrale Forschungswerkstatt</title>
    <abstract language="deu">Die Zentralwerkstatt der BAM übernimmt die Fertigung und Konstruktion komplexer Prüf- und Versuchseinrichtungen und adressiert zugleich zentrale Forschungsthemen zur Werkstoff- und Komponentensicherheit. Dazu gehören die Entwicklung innovativer Fertigungstechnologien, ressourceneffiziente Verarbeitungskonzepte für hochfeste und additive Komponenten sowie die Untersuchung von Fertigungseinflüssen auf Oberflächenintegrität und Werkstoffdegradation. Ein besonderer Fokus liegt auf der H₂-Sicherheit, insbesondere der Fertigung und Prüfung von Hohlzugproben für Wasserstoff-Pipelines. Ergänzend werden Automatisierungslösungen, digitale Methoden und moderne Spanntechnik zur Effizienzsteigerung eingesetzt. Die Arbeiten sind eng mit den BAM-Kompetenzzentren AM@BAM, H2Safety@BAM und WIND@BAM verzahnt und leisten einen Beitrag zur Energiewende sowie zur Normung und zum Technologietransfer.</abstract>
    <enrichment key="eventName">37. Stammtisch Metall des "Der Mittelstand BVMW e.V. "</enrichment>
    <enrichment key="eventPlace">Berlin, Germany</enrichment>
    <enrichment key="eventStart">17.09.2025</enrichment>
    <enrichment key="eventEnd">17.09.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Werkstoffsicherheit</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>H₂-Sicherheit</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Additive Fertigung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Ressourceneffizienz</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Automatisierung in der Fertigung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Prüftechnikentwicklung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Normung und Technologietransfer</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Oberflächenintegrität</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Wasserstoff</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
    <collection role="themenfelder" number="">Leichtbau</collection>
  </doc>
  <doc>
    <id>65243</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">HGF-AK "Bau wissenschaftlicher Geräte" - Neues aus der BAM / Fachbereich 9.2</title>
    <abstract language="deu">In dieser Präsentation werden die neuesten Herausforderungen und der Stand des Fachbereiches 9.2 für die Mitarbeit im AK des HGF "Bau wissenschaftlicher Geräte" dargestellt. Hierfür werden Neuigkeiten aus dem Bereich Materialprüfung in der BAM präsentiert und mit den Arbeiten der Zentralwerkstatt, die hierfür notwendig sind, in Zusammenhang gebracht.</abstract>
    <enrichment key="eventName">20. Jahrestagung des Helmholtz-Arbeitskreis "Bau wissenschaftlicher Geräte"</enrichment>
    <enrichment key="eventPlace">Jülich, Germany</enrichment>
    <enrichment key="eventStart">07.05.2025</enrichment>
    <enrichment key="eventEnd">08.05.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Fertigungskompetenz</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Fertigungsverfahren</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Wasserstoff</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
    <collection role="themenfelder" number="">Leichtbau</collection>
  </doc>
  <doc>
    <id>50278</id>
    <completedYear/>
    <publishedYear>2019</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Von der Anwendung ins Prüflabor: Maßstabsgetreues Bewerten von Spannungen in geschweißten Bauteilen</title>
    <abstract language="deu">Eigenspannungen sind von zentraler Bedeutung für die Performance geschweißter Bauteile. Die Bewertung schweißbedingter Beanspruchungen im Labormaßstab ist oft nicht zielführend. Reale Bauteilschweißungen weisen geometrisch und konstruktiv bedingt meist divergente Wärmeableitungs- und Einspannbedingungen auf. Dadurch lassen sich häufig nur eingeschränkt Aussagen über Eigenspannungshöhen, -verteilungen und die wesentlichen Einflussfaktoren treffen. Dies führt oftmals zur eher konservativen Konstruktionsauslegung und damit zu einer geringeren Ressourcen- und Energieeffizienz. Dieser Beitrag widmet sich den Bestrebungen, reale Randbedingungen beim Bauteilschweißen in das Labor zu übertragen. Es werden die Möglichkeiten eines speziell für diesen Zweck an der BAM entwickelten Prüfsystems mit einer maximalen Tragkraft von 2 MN aufgezeigt. Durch die konstruktive Gestaltung der Anlage lassen sich in Schweißversuchen schweißbedingte Beanspruchungen nachbilden und die komplexen Einflüsse und Wechselwirkungen durch Schweißprozess, Bauteilgeometrie und -konstruktion sowie durch die eingesetzten Grund- und Zusatzwerkstoffe quantifizieren. Darüber hinaus können mittels Röntgenbeugung die resultierenden lokalen Eigenspannungen präzise und mit hoher Ortsauflösung bestimmt werden. Anhand von Beispielen wird die Nachbildung realer Produktionsbedingungen im Labor erörtert und gezeigt, wie die Spannungen beim Schweißen hochfester Baustähle von konstruktiven, werkstoff- und prozessseitigen Randbedingungen abhängen. So wurde geklärt, wie erhöhte Arbeitstemperaturen zum signifikanten Anstieg der Beanspruchungen führen.</abstract>
    <enrichment key="eventName">DVS Congress</enrichment>
    <enrichment key="eventPlace">Rostock, Germany</enrichment>
    <enrichment key="eventStart">16.09.2019</enrichment>
    <enrichment key="eventEnd">17.09.2019</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Schweißen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Eigenspannungen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Bauteilprüfung</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>50277</id>
    <completedYear/>
    <publishedYear>2019</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Influence of welding stresses on relaxation cracking during heat treatment of a creep-resistant 13CrMoV steel - Part I</title>
    <abstract language="eng">Over the past years economic and environmental considerations have led to a markedly increased demand for efficiency and flexibility in petrochemical plants. The operational temperatures and pressures required today can only be achieved by using new creep-resistant grades of steel. The modified 13CrMoV9-10 vanadium steel shows a good resistance against creep and compressed hydrogen and has been in use for the construction of petrochemical reactors since the mid-1990s. Nevertheless, processing of this type of steel requires extreme care during the welding procedure. This is due to its low toughness and high strength in the welded state when not post weld heat treated combined with increased susceptibility to cracking during stress relaxation. Previous research into crack formation in creep-resistant steels has largely focused on thermal and metallurgical factors; however, little knowledge has been gathered regarding the influence of the welding procedure on crack formation during post weld heat treatment considering real-life manufacturing conditions. The influence of heat control on the mechanical properties has been investigated by simulating the welding and subsequent post weld heat treatment operations during the construction of petrochemical reactors using a special 3-D testing facility on the laboratory scale.&#13;
This work is subdivided in two parts. In part I of this study the stresses resulting from preheating, welding, dehydrogenation heat treatment and the final post weld heat treatment were analyzed during experiments under varied heat control. In all experiments stress relief cracks formed during post weld heat treatment could be observed. The total crack lengths correlated with the welding induced stresses. &#13;
Part II of this work is dedicated to the characterization of the cracks and the microstructure. The application of a special acoustic emission analysis indicated that the cracks formed in a temperature range between 300 °C and 500 °C during the post weld heat treatment. In comparison to small scale specimens welded without additional shrinkage restraint, the toughness of the restrained welds was significantly decreased. SEM and TEM analyses of all samples revealed accelerated aging due to early precipitation of special carbides during post weld heat treatment under component relevant restraint.</abstract>
    <enrichment key="eventName">IIW Annual Assembly</enrichment>
    <enrichment key="eventPlace">Bratislava, Slovakia</enrichment>
    <enrichment key="eventStart">08.07.2019</enrichment>
    <enrichment key="eventEnd">12.07.2019</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Creep-resistant steel</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Post weld heat treatment</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Stress relief cracking</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Welding</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>47725</id>
    <completedYear/>
    <publishedYear>2019</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Kaltrissvermeidung in Schweißverbindungen aus hochfesten Feinkornbaustählen bei engen Nahtspalten und fokussiertem Lichtbogen</title>
    <abstract language="deu">Heute werden in Stahlkonstruktionen zunehmend hochfeste Baustähle (Streckgrenze ≥ 960 MPa) eingesetzt. Daher sind auch in Schweißnähten solche hohen Festigkeiten gefordert. Jedoch können hohe Eigenspannungen aufgrund geringerer plastischer Dehnungsreserven in diesen Schweißnähten die Sicherheit der Bauteile vermindern. Diese sind insbesondere im Zusammenhang mit Wasserstoff und Härtegefügen risskritisch. Niedrige Bauteilbeanspruchungen und Kosteneinsparungen lassen sich heutzutage mit modernen fokussierten Lichtbogenvarianten und engeren Nahtspalten erreichen. Die vorliegende Studie zeigt allerdings, dass diese modernen Schweißprozesse und die angepasste Nahtgeometrie höhere Wasserstoffkonzentrationen und signifikant gesteigerte oberflächennahe Zugeigenspannungsniveaus bedingen. Anhand mehrlagiger Schweißversuche an S960QL unter Variation von Wärmeführung, Lichtbogenvariante und Nahtöffnungswinkel wurden die Effekte und Wechselwirkungen unter Zuhilfenahme von Eigenspannungsanalytik mittels Röntgendiffraktometrie und Wasserstoffanalytik mittels Trägergasheißextraktion systematisch untersucht. Das Schweißgefüge führte unter kritischer mechanischer Beanspruchung und erhöhtem Gehalt an diffusiblem Wasserstoff insbesondere bei geringem Nahtöffnungswinkel und fokussiertem Lichtbogen zu einer deutlichen Ausbildung von Mikrorissen. Die Mikrorisse führten teils zu einer makroskopischen Ausprägung. Durch Analysen zur Nachwärmung aus der Schweißwärme heraus konnten suffiziente Wärmeführungsparameter für eine effektive Prävention solcher Risse erarbeitet werden. Die vorliegende Arbeit zeigt anhand des Interaktionssystems bei der wasserstoffunterstützten Kaltrissbildung Gefüge-Beanspruchung-Wasserstoff, welche Wärmeführungs- und Schweißparameter sich für die hochfesten Feinkornbaustähle zur Kaltrissvermeidung eignen.</abstract>
    <enrichment key="eventName">3. Niedersächsisches Symposium Materialtechnik</enrichment>
    <enrichment key="eventPlace">Clausthal-Zellerfeld, Germany</enrichment>
    <enrichment key="eventStart">14.02.2019</enrichment>
    <enrichment key="eventEnd">15.02.2019</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Eigenspannungen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Hochfeste Feinkornbaustähle</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Kaltrisse</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>MAG-Schweißen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Wasserstoff</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Wärmeführung</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
  </doc>
  <doc>
    <id>65189</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Wear resistance of modified Ni based claddings in relation to the resulting machinability via ultrasonic-assisted milling</title>
    <abstract language="eng">In the field of plastics processing, extruder screws are subjected to significant wear stresses. The extruder screw is the main wear component in those production machines and is usually coated with intermetallic wear protection alloys composed of Ni-based alloys, specifically Colmonoy C56 PTA (NiMoCrSi). There is a growing demand for providing an economic machinability of these alloys to achieve defined contours with a sufficient surface integrity. Recent investigations exhibit promising results applying ultrasonic milling for such hard-to-cut materials. The Colmonoy C56 is modified by various alloying additions Ti, Nb, Mo, Hf, and Al, and then cladded on a steel S355 via Plasma Transferred Arc process. The effect of alloying additions on the microstructure is analyzed regarding their resistance to abrasive and adhesive wear. With Miller test ASTM G75 the influence of alloying elements on resistance to abrasive wear for two abrasive materials is investigated (high-grade corundum F220 and quartz powder). The wear loss is not increased for additions of Nb and Ti compared to the base material C56. Modifications with Hf or Al reduces the resistance to abrasive wear and significantly increases material loss. The extruder screw is also subject to adhesive wear, which can be quantified by means of the pin-roll test. It is demonstrated that the addition of Hf, for example, contributes to a reduction in wear loss. Aim of the investigations is to find suitable modifications for the wear claddings of C56 for a sufficient machineability, without compemising the wear resistant. The machinability is considerably affected by the alloy additions, and is determined using ultrasonic-assisted milling. The addition of hafnium reduces machinability, i.e. significantly increases cutting forces. The incorporation of Nb exhibits a significant reduction of cutting forces, and results in reduced tool wear and an enhanced of surface integrity (roughness, density of defects, residual stresses).</abstract>
    <enrichment key="eventName">Wear of Materials 2025</enrichment>
    <enrichment key="eventPlace">Sitges, Spain</enrichment>
    <enrichment key="eventStart">13.04.2025</enrichment>
    <enrichment key="eventEnd">17.04.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Abrasive wear</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Adhesive wear</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Colmonoy C56</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>PTA welding</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Service life and efficiency</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Substitution of critical raw materials</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Surface integrity</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic-assisted milling process</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
  </doc>
  <doc>
    <id>65215</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Comparative residual stress analysis on a DED-Arc manufactured high-strength steel component using the contour method and XRD</title>
    <abstract language="eng">Lightweight construction is a vital approach for reducing CO₂ emissions. It contributes to the development of more energy-efficient structures and supports the overall goal of achieving carbon neutrality in the transition to sustainable manufacturing. Thus, a topology-optimized design often leads to complex geometries. Additive manufacturing (AM) processes such as direct energy deposition with arc (DED-Arc) offers a great design freedom due to the build-up of components in layers. Furthermore, they enable efficient production due to the high deposition rate, process reliability and good automation capability. Further efficiency can be achieved through weight optimization, enabled by high-strength steels. However, a major challenge is the process induced residual stresses (RS) in the component. High tensile residual stresses are detrimental as they increase the risk of cold cracking. Knowledge of residual stress distribution is crucial for predicting service life of the component and structural integrity assessment, especially for safety critical applications. Therefore, this study focuses on the use of Contour method (CM) to analyse the full field longitudinal residual stresses in an open hollow cuboid component (dimensions: 120 x 50 x 30 mm3) manufactured by DED-Arc (yield strength &gt; 730 MPa). In the contour method, the component is cut along a desired plane of interest and the contour of deformed cut surface is measured. A finite element model is used to reconstruct the residual stresses field in the 2-dimensional plane of cut. In this paper a modified cutting strategy was employed, post cutting the deformed cut surfaces were measured utilizing two surface measurement techniques i.e., coordinate measuring machine (CMM) and a 3D Scanner. The accuracy of the contour method was validated against surface stresses measured using X-ray diffraction. Additionally, a comparison of neutron diffraction experiments was conducted. The residual stresses were further correlated with hardness measurements. The results from surface measurement techniques showed good agreement regarding the measured displacement contours and the contour method results revealed peak stresses in the DED-Arc walls, bending deformation in substrate induces tensile stresses at the bottom of the substrate plate and compressive stresses in the middle top region. The residual stresses obtained from diffraction and contour method showed a good agreement and correlated qualitatively with the hardness measurements.</abstract>
    <enrichment key="eventName">78th IIW Annual Assembly and International Conference on Welding and Joining</enrichment>
    <enrichment key="eventPlace">Genoa, Italy</enrichment>
    <enrichment key="eventStart">22.06.2025</enrichment>
    <enrichment key="eventEnd">27.06.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stress</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Contour method</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DED-Arc/M</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High-strength steel</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Filler metals</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>XRD</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Neutron diffraction</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
    <collection role="themenfelder" number="">Leichtbau</collection>
  </doc>
  <doc>
    <id>65209</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>lecture</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Residual stress evaluation using the contour method of an additive manufactured high-strength steel solid cuboid</title>
    <abstract language="eng">Direct Energy Deposition with Arc (DED-Arc) enables the weight-optimized and near-net-shape manufacturing of complex structures. Lightweight construction principles allow a reduction of CO2 emissions by saving time, costs, and resources. Further optimisations can be achieved by using high-strength steel. This allows for a reduction in wall thickness and optimisation of weight. However, manufacturing intricate geometries using high-strength steels poses challenges in managing residual stresses (RS), which are essential for ensuring the structural integrity of welded components. High residual stresses can increase the risk of cold cracking, arising from the complex interactions between material properties, process conditions, and component design. Despite the availability of suitable filler metals, the lack of comprehensive knowledge and guidelines on residual stress formation limits the industrial application. &#13;
Therefore, in the present study, the contour method (CM) was used to analyse the full field longitudinal residual stresses in an solid cuboid component (dimensions: 120 × 50 × 35 mm³) manufactured by DED-Arc. The CM enables the analysis of the two-dimensional map of residual stresses normal to a cutting plane using a finite element model. For this purpose, a solid cuboid component was welded fully automatically with a high-strength solid wire specially adapted for DED-Arc (yield strength &gt; 790 MPa) onto conventionally manufactured substrates made of S690QL. The residual stresses from CM in the volume are compared with residual stress analyses using X-Ray diffraction on the surface. Additionally, comparative data from previous studies on hollow cuboid structures was included in order to identify similarities and differences in the resulting stress state, and to complement and validate the CM results. These results demonstrate the significant influence of the geometry on the residual stress profiles within the solid cuboid in relation to the open hollow.</abstract>
    <enrichment key="eventName">4th International Conference on Advanced Joining Processes 2026</enrichment>
    <enrichment key="eventPlace">Coimbra, Portugal</enrichment>
    <enrichment key="eventStart">16.10.2025</enrichment>
    <enrichment key="eventEnd">17.10.2025</enrichment>
    <enrichment key="InvitedTalks">0</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>Dirk Schröpfer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Residual stress</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Contour method</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DED-Arc/M</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High-strength steel</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Filler metals</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Neutron diffraction</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="">9 Komponentensicherheit</collection>
    <collection role="institutes" number="">9.2 Versuchsanlagen und Prüftechnik</collection>
    <collection role="institutes" number="">9.4 Integrität von Schweißverbindungen</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Material</collection>
    <collection role="themenfelder" number="">Degradationsmechanismen</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Präsentation</collection>
    <collection role="themenfelder" number="">Additive Fertigung</collection>
    <collection role="themenfelder" number="">Windenergie</collection>
    <collection role="themenfelder" number="">Leichtbau</collection>
  </doc>
</export-example>
