Structural integrity of Ni-base alloy welds

Hannu Hänninen, Anssi Brederholm, Teemu Sarikka, Roman Mouginot, Petra Holmström, Tapio Saukkonen, Aki Toivonen, Päivi Karjalainen-Roikonen, Pekka Nevasmaa, Heikki Keinänen, Esa Leskelä, Matias Ahonen, Ulla Ehrnsten, Pertti Aaltonen

    Research output: Book/ReportReport

    Abstract

    The Tekes project Structural integrity of Ni-base alloy welds (SINI) was carried out at Aalto University and VTT during the period from 2010 to 2014. In nuclear industry applications, the degradation of Ni-base alloy dissimilar metal welds (DMWs), both in pressurised water reactor (PWR) and in boiling water reactor (BWR) plants, is an extensive international problem. The project participates with ongoing international cooperation in USA (Electric Power Research Institute EPRI, Alloy 690/52/152 PWSCC Research Collaboration) and in Japan (Tohoku University) for the conduction of new Ni-base alloy research. The research need is actual, especially because indications have been found in the DMWs in the reactor pressure vessel nozzle of BWRs similar to Finnish BWR designs and European pressurised water reactor (EPR PWR) -plant under construction contains a large number of varying and new types of dissimilar metal welds of which no previous experience is available. The main focus of the project was to investigate the weldability of Alloy 690 base metal corresponding filler metal Alloy 52 and the properties of the welded joint. Comparable reactor pressure vessel (RPV) safe-end weld joint was made by narrow-gap tungsten inert gas (TIG) welding with Alloy 52 filler metal for research purposes. Also prototypical BWR reactor pressure vessel (RPV) safe-end weld joint was made with Alloy 82/182 filler metals. Determination of the mechanical properties and characterization of the microstructures of the welded joints were conducted. Crack initiation tests in autoclave were made in different environments. After PINC (Program for the Inspection of Nickel Alloy Components) round-robin program new PARENT (Program to Assess Reliability of Emerging Non-destructive Techniques for Dissimilar Metal Welds) round-robin program was started where VTT participated. Based on the PINC results, new non-destructive testing methods were developed to enhance the reliability of detection and accuracy of sizing of flaws in nickel-based alloy dissimilar metal welds. Separate reports: 1. Holmström, P. (2012), The effect of mismatch on the mechanical properties of a dissimilar metal weld. M.Sc. Thesis, Aalto University, Espoo, Finland, 162 p. + app. 4 p. 2. Mouginot, R. and Hänninen, H. (2013), Microstructures of nickel-base alloy dissimilar metal welds. Aalto University publication series SCIENCE + TECHNOLOGY, 5/2013, https://aaltodoc.aalto.fi/handle/123456789/9006, Aalto University, Espoo, Finland, 178 p. 3. Keinänen, H. (2013), Computational estimation of the risk of hot cracking in narrow gap welding. Research report VTT-R-08369-13, VTT Technical Research Centre of Finland, Espoo, Finland, 27 p. + app. 10 p.
    Original languageEnglish
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Number of pages264
    ISBN (Electronic)978-951-38-8260-0
    ISBN (Print)978-951-38-8259-4
    Publication statusPublished - 2014
    MoE publication typeNot Eligible

    Publication series

    SeriesVTT Technology
    Volume175
    ISSN2242-1211

    Fingerprint

    Structural integrity
    Welds
    Dissimilar metals
    Filler metals
    Boiling water reactors
    Pressurized water reactors
    Pressure vessels
    Nickel alloys
    Application programs
    Inspection
    Nickel
    Inert gas welding
    Mechanical properties
    Microstructure
    Nuclear industry
    Weldability
    International cooperation
    Autoclaves
    Nondestructive examination
    Crack initiation

    Keywords

    • nickel-base alloys
    • welding
    • weld metal
    • dissimilar metal welds
    • nuclear power plant
    • environment-assisted cracking
    • fracture toughness
    • scanning electron microscopy
    • NDT

    Cite this

    Hänninen, H., Brederholm, A., Sarikka, T., Mouginot, R., Holmström, P., Saukkonen, T., ... Aaltonen, P. (2014). Structural integrity of Ni-base alloy welds. Espoo: VTT Technical Research Centre of Finland. VTT Technology, Vol.. 175
    Hänninen, Hannu ; Brederholm, Anssi ; Sarikka, Teemu ; Mouginot, Roman ; Holmström, Petra ; Saukkonen, Tapio ; Toivonen, Aki ; Karjalainen-Roikonen, Päivi ; Nevasmaa, Pekka ; Keinänen, Heikki ; Leskelä, Esa ; Ahonen, Matias ; Ehrnsten, Ulla ; Aaltonen, Pertti. / Structural integrity of Ni-base alloy welds. Espoo : VTT Technical Research Centre of Finland, 2014. 264 p. (VTT Technology, Vol. 175).
    @book{4b3640a8d3c24ec8a63fe5a2c4101e31,
    title = "Structural integrity of Ni-base alloy welds",
    abstract = "The Tekes project Structural integrity of Ni-base alloy welds (SINI) was carried out at Aalto University and VTT during the period from 2010 to 2014. In nuclear industry applications, the degradation of Ni-base alloy dissimilar metal welds (DMWs), both in pressurised water reactor (PWR) and in boiling water reactor (BWR) plants, is an extensive international problem. The project participates with ongoing international cooperation in USA (Electric Power Research Institute EPRI, Alloy 690/52/152 PWSCC Research Collaboration) and in Japan (Tohoku University) for the conduction of new Ni-base alloy research. The research need is actual, especially because indications have been found in the DMWs in the reactor pressure vessel nozzle of BWRs similar to Finnish BWR designs and European pressurised water reactor (EPR PWR) -plant under construction contains a large number of varying and new types of dissimilar metal welds of which no previous experience is available. The main focus of the project was to investigate the weldability of Alloy 690 base metal corresponding filler metal Alloy 52 and the properties of the welded joint. Comparable reactor pressure vessel (RPV) safe-end weld joint was made by narrow-gap tungsten inert gas (TIG) welding with Alloy 52 filler metal for research purposes. Also prototypical BWR reactor pressure vessel (RPV) safe-end weld joint was made with Alloy 82/182 filler metals. Determination of the mechanical properties and characterization of the microstructures of the welded joints were conducted. Crack initiation tests in autoclave were made in different environments. After PINC (Program for the Inspection of Nickel Alloy Components) round-robin program new PARENT (Program to Assess Reliability of Emerging Non-destructive Techniques for Dissimilar Metal Welds) round-robin program was started where VTT participated. Based on the PINC results, new non-destructive testing methods were developed to enhance the reliability of detection and accuracy of sizing of flaws in nickel-based alloy dissimilar metal welds. Separate reports: 1. Holmstr{\"o}m, P. (2012), The effect of mismatch on the mechanical properties of a dissimilar metal weld. M.Sc. Thesis, Aalto University, Espoo, Finland, 162 p. + app. 4 p. 2. Mouginot, R. and H{\"a}nninen, H. (2013), Microstructures of nickel-base alloy dissimilar metal welds. Aalto University publication series SCIENCE + TECHNOLOGY, 5/2013, https://aaltodoc.aalto.fi/handle/123456789/9006, Aalto University, Espoo, Finland, 178 p. 3. Kein{\"a}nen, H. (2013), Computational estimation of the risk of hot cracking in narrow gap welding. Research report VTT-R-08369-13, VTT Technical Research Centre of Finland, Espoo, Finland, 27 p. + app. 10 p.",
    keywords = "nickel-base alloys, welding, weld metal, dissimilar metal welds, nuclear power plant, environment-assisted cracking, fracture toughness, scanning electron microscopy, NDT",
    author = "Hannu H{\"a}nninen and Anssi Brederholm and Teemu Sarikka and Roman Mouginot and Petra Holmstr{\"o}m and Tapio Saukkonen and Aki Toivonen and P{\"a}ivi Karjalainen-Roikonen and Pekka Nevasmaa and Heikki Kein{\"a}nen and Esa Leskel{\"a} and Matias Ahonen and Ulla Ehrnsten and Pertti Aaltonen",
    note = "Project code: 71232",
    year = "2014",
    language = "English",
    isbn = "978-951-38-8259-4",
    series = "VTT Technology",
    publisher = "VTT Technical Research Centre of Finland",
    address = "Finland",

    }

    Hänninen, H, Brederholm, A, Sarikka, T, Mouginot, R, Holmström, P, Saukkonen, T, Toivonen, A, Karjalainen-Roikonen, P, Nevasmaa, P, Keinänen, H, Leskelä, E, Ahonen, M, Ehrnsten, U & Aaltonen, P 2014, Structural integrity of Ni-base alloy welds. VTT Technology, vol. 175, VTT Technical Research Centre of Finland, Espoo.

    Structural integrity of Ni-base alloy welds. / Hänninen, Hannu; Brederholm, Anssi; Sarikka, Teemu; Mouginot, Roman; Holmström, Petra; Saukkonen, Tapio; Toivonen, Aki; Karjalainen-Roikonen, Päivi; Nevasmaa, Pekka; Keinänen, Heikki; Leskelä, Esa; Ahonen, Matias; Ehrnsten, Ulla; Aaltonen, Pertti.

    Espoo : VTT Technical Research Centre of Finland, 2014. 264 p. (VTT Technology, Vol. 175).

    Research output: Book/ReportReport

    TY - BOOK

    T1 - Structural integrity of Ni-base alloy welds

    AU - Hänninen, Hannu

    AU - Brederholm, Anssi

    AU - Sarikka, Teemu

    AU - Mouginot, Roman

    AU - Holmström, Petra

    AU - Saukkonen, Tapio

    AU - Toivonen, Aki

    AU - Karjalainen-Roikonen, Päivi

    AU - Nevasmaa, Pekka

    AU - Keinänen, Heikki

    AU - Leskelä, Esa

    AU - Ahonen, Matias

    AU - Ehrnsten, Ulla

    AU - Aaltonen, Pertti

    N1 - Project code: 71232

    PY - 2014

    Y1 - 2014

    N2 - The Tekes project Structural integrity of Ni-base alloy welds (SINI) was carried out at Aalto University and VTT during the period from 2010 to 2014. In nuclear industry applications, the degradation of Ni-base alloy dissimilar metal welds (DMWs), both in pressurised water reactor (PWR) and in boiling water reactor (BWR) plants, is an extensive international problem. The project participates with ongoing international cooperation in USA (Electric Power Research Institute EPRI, Alloy 690/52/152 PWSCC Research Collaboration) and in Japan (Tohoku University) for the conduction of new Ni-base alloy research. The research need is actual, especially because indications have been found in the DMWs in the reactor pressure vessel nozzle of BWRs similar to Finnish BWR designs and European pressurised water reactor (EPR PWR) -plant under construction contains a large number of varying and new types of dissimilar metal welds of which no previous experience is available. The main focus of the project was to investigate the weldability of Alloy 690 base metal corresponding filler metal Alloy 52 and the properties of the welded joint. Comparable reactor pressure vessel (RPV) safe-end weld joint was made by narrow-gap tungsten inert gas (TIG) welding with Alloy 52 filler metal for research purposes. Also prototypical BWR reactor pressure vessel (RPV) safe-end weld joint was made with Alloy 82/182 filler metals. Determination of the mechanical properties and characterization of the microstructures of the welded joints were conducted. Crack initiation tests in autoclave were made in different environments. After PINC (Program for the Inspection of Nickel Alloy Components) round-robin program new PARENT (Program to Assess Reliability of Emerging Non-destructive Techniques for Dissimilar Metal Welds) round-robin program was started where VTT participated. Based on the PINC results, new non-destructive testing methods were developed to enhance the reliability of detection and accuracy of sizing of flaws in nickel-based alloy dissimilar metal welds. Separate reports: 1. Holmström, P. (2012), The effect of mismatch on the mechanical properties of a dissimilar metal weld. M.Sc. Thesis, Aalto University, Espoo, Finland, 162 p. + app. 4 p. 2. Mouginot, R. and Hänninen, H. (2013), Microstructures of nickel-base alloy dissimilar metal welds. Aalto University publication series SCIENCE + TECHNOLOGY, 5/2013, https://aaltodoc.aalto.fi/handle/123456789/9006, Aalto University, Espoo, Finland, 178 p. 3. Keinänen, H. (2013), Computational estimation of the risk of hot cracking in narrow gap welding. Research report VTT-R-08369-13, VTT Technical Research Centre of Finland, Espoo, Finland, 27 p. + app. 10 p.

    AB - The Tekes project Structural integrity of Ni-base alloy welds (SINI) was carried out at Aalto University and VTT during the period from 2010 to 2014. In nuclear industry applications, the degradation of Ni-base alloy dissimilar metal welds (DMWs), both in pressurised water reactor (PWR) and in boiling water reactor (BWR) plants, is an extensive international problem. The project participates with ongoing international cooperation in USA (Electric Power Research Institute EPRI, Alloy 690/52/152 PWSCC Research Collaboration) and in Japan (Tohoku University) for the conduction of new Ni-base alloy research. The research need is actual, especially because indications have been found in the DMWs in the reactor pressure vessel nozzle of BWRs similar to Finnish BWR designs and European pressurised water reactor (EPR PWR) -plant under construction contains a large number of varying and new types of dissimilar metal welds of which no previous experience is available. The main focus of the project was to investigate the weldability of Alloy 690 base metal corresponding filler metal Alloy 52 and the properties of the welded joint. Comparable reactor pressure vessel (RPV) safe-end weld joint was made by narrow-gap tungsten inert gas (TIG) welding with Alloy 52 filler metal for research purposes. Also prototypical BWR reactor pressure vessel (RPV) safe-end weld joint was made with Alloy 82/182 filler metals. Determination of the mechanical properties and characterization of the microstructures of the welded joints were conducted. Crack initiation tests in autoclave were made in different environments. After PINC (Program for the Inspection of Nickel Alloy Components) round-robin program new PARENT (Program to Assess Reliability of Emerging Non-destructive Techniques for Dissimilar Metal Welds) round-robin program was started where VTT participated. Based on the PINC results, new non-destructive testing methods were developed to enhance the reliability of detection and accuracy of sizing of flaws in nickel-based alloy dissimilar metal welds. Separate reports: 1. Holmström, P. (2012), The effect of mismatch on the mechanical properties of a dissimilar metal weld. M.Sc. Thesis, Aalto University, Espoo, Finland, 162 p. + app. 4 p. 2. Mouginot, R. and Hänninen, H. (2013), Microstructures of nickel-base alloy dissimilar metal welds. Aalto University publication series SCIENCE + TECHNOLOGY, 5/2013, https://aaltodoc.aalto.fi/handle/123456789/9006, Aalto University, Espoo, Finland, 178 p. 3. Keinänen, H. (2013), Computational estimation of the risk of hot cracking in narrow gap welding. Research report VTT-R-08369-13, VTT Technical Research Centre of Finland, Espoo, Finland, 27 p. + app. 10 p.

    KW - nickel-base alloys

    KW - welding

    KW - weld metal

    KW - dissimilar metal welds

    KW - nuclear power plant

    KW - environment-assisted cracking

    KW - fracture toughness

    KW - scanning electron microscopy

    KW - NDT

    M3 - Report

    SN - 978-951-38-8259-4

    T3 - VTT Technology

    BT - Structural integrity of Ni-base alloy welds

    PB - VTT Technical Research Centre of Finland

    CY - Espoo

    ER -

    Hänninen H, Brederholm A, Sarikka T, Mouginot R, Holmström P, Saukkonen T et al. Structural integrity of Ni-base alloy welds. Espoo: VTT Technical Research Centre of Finland, 2014. 264 p. (VTT Technology, Vol. 175).