4
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Low heat input welding of nickel superalloy GTD-111 with Inconel 625 filler metal Translated title: Schweißen einer Nickel-Superlegierung GTD-111 mit einem Inconel 625 Zusatzwerkstoff

      research-article

      Read this article at

      ScienceOpenPublisher
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          GTD-111 precipitation-strengthened nickel-based superalloy is widely used in blades of gas turbine engines which operate at high temperature and in a hot localized corrosion atmosphere. After long-term exposure to high temperature, γ' precipitate is known to exhibit catastrophic changes in size and distribution which cause deterioration of its properties and failure of the component. In this study, a damaged blade removed froma land-based gas turbine generator was subjected to nonpre-heat-treated GTAW and laser welding repair with various welding powers in the range of 135 to 295 J × mm −1, followed by post-weld heat treatment (PWHT) at 1473 K for 7200 s and strain aging at 1118 K for 86 400 s. Results show no significant relationship between welding powers, size and area fraction of the γ' precipitate in the fcc γ matrix in both GTAW and laser-welded specimens. The final γ' precipitate size and distribution depend mainly on PWHT parameters as γ' precipitates in all GTAW and laser welded specimens showed similar size and area fraction independently of the heat input from welding. Unmixed zones are observed in all laser welding specimens which may cause preferential weld corrosion during service. Microcrack occurrence due to welding and PWHT processes is also discussed.

          Kurzfassung

          Die ausscheidungsverfestigende Nickel-Superlegierung GTD-111 wird breitflächig für Schaufeln von Gasturbinen verwendet, die bei hohen Temperaturen und in heißen korrosiven Umgebungen eingesetzt werden. Nach einer langen Zeit der Exposition bei hohen Temperaturen können Ausscheidungen des γ'-Typs bekanntermaßen katastrophale Veränderungen der Größe und Verteilung bilden und so eine Herabsetzung der Eigenschaften des Werkstoffes und Versagen der Komponenten nach sich ziehen. In der diesem Beitrag zugrundeliegenden Studie wurde eine beschädigte Schaufel, die aus einem Gasturbinen-Generator an Land ausgebaut wurde, mittels Wolfram-Inertgas-Schweißens (WIG) und Laserschweißens repariert, und zwar mit verschiedenen Streckenenergien im Bereich von 135 bis 295 J × mm −1, gefolgt von einer Wärmenachbehandlung bei 1473 K für 7200 s und einer Auslagerung bei 1118 K für 86 400 s. Die Ergebnisse zeigen keine signifikante Abhängigkeit zwischen den Schweißleistungen sowie der Größe und des Flächenanteiles der γ'-Ausscheidungen in kubisch flächenzentrierte (fcc) γ-Matrix, und zwar sowohl beim WIG- als auch beim Laserschweißen. Die finale Größe und Verteilung der γ'-Ausscheidungen hängt vornehmlich von den Parametern der Wärmenachbehandlung ab, da die γ'-Ausscheidungen in allen WIG- und lasergeschweißten Proben eine ähnliche Größe und ähnliche Flächenanteile unabhängig von der beim Schweißen eingebrachten Wärme aufweisen. Es wurde eine Entmischungszone in allen Laserschweißungen beobachtet, wo präferentielle Korrosion im Betrieb auftreten kann. Das Auftreten von Mikrorissen während des Schweißens und der Wärmenachbehandlung wird ebenfalls diskutiert.

          Related collections

          Most cited references19

          • Record: found
          • Abstract: not found
          • Article: not found

          Effect of ultrasonic vibration on unmixed zone formation

          Y Cui, C XU, Q HAN (2006)
            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            Study of the fusion zone and heat-affected zone microstructures in tungsten inert gas-welded INCONEL 738LC superalloy

              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              The liquation cracking behavior of IN738LC superalloy during low power Nd:YAG pulsed laser welding

                Bookmark

                Author and article information

                Journal
                mp
                Materials Testing
                Carl Hanser Verlag
                0025-5300
                2195-8572
                4 January 2018
                : 60
                : 1
                : 22-30
                Affiliations
                1 Bangkok, Thailand
                Author notes
                [* ] Correspondence Address, Dr. Panyawat Wangyao, Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Patumwan, Bangkok 10330, Thailand E-Mail: panyawat.w@ 123456chula.ac.th

                Athittaya Athiroj, born in 1984, is a graduate student in the Department of Metallurgical Engineering, Chulalongkorn University, Bangkok, Thailand. Her research scope is related to the development and characterization of the welding of precipitation-strengthened nickel-based superalloys. She received her Bachelor degree in Metallurgical Engineering from Chulalongkorn University in 2007. Currently, she is employed as an inspection engineer in Bangchak Corporation, Thailand.

                Dr. Panyawat Wangyao, born in 1971, is a member of the Innovative Metals Research Unit and served as Head of the Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand from 2011 to 2015. He received his PhD in Physical Metallurgy from Technical University of Kosice, Slovakia, in 2002. His research areas of expertise include high temperature materials such as superalloys, super stainless steels as well as powder metallurgy of alloys.

                Prof. Dr.-Ing. Fritz Hartung, is a visiting professor in the Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand. He received his Master degree and Dr.-Ing. in Mechanical Engineering from University of Technology Magdeburg, Germany, in 1969 and 1975, respectively. He was Head of the Faculty of Technology Mechanical Engineering, Trier University of Applied Science, Germany. His areas of expertise are welding and metal joining.

                Associate Prof. Dr.-Ing. Gobboon Lothongkum, born in 1960, is Associate Professor and a member of the Innovative Metals Research Unit, Department of Metallurgical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand. He has been serving as Head of the department since 2015. He received his Dr.-Ing. degree from University of the Federal Armed Force Hamburg, Germany and the International Welding Engineer Certificate of the International Institute of Welding in 1994 and 2006, respectively. His areas of expertise include corrosion of metals and alloys, welding and metal joining, stainless steels and high temperature materials.

                Article
                MP111131
                10.3139/120.111131
                2175ae99-1656-4bd8-b00e-70d9fca1ec28
                © 2018, Carl Hanser Verlag, München
                History
                Page count
                References: 23, Pages: 9
                Categories
                Fachbeiträge/Technical Contributions

                Materials technology,Materials characterization,Materials science
                Materials technology, Materials characterization, Materials science

                Comments

                Comment on this article