Artificial flaw simulation in ultrasonic inspection of austenitic stainless steel weld

Master's thesis

    Research output: ThesisMaster's thesisTheses

    Abstract

    Nuclear power plant primary circuit components are made from austenitic stainless steels. They provide mechanical properties combined with corrosion resistance and weldability. The structural integrity of the components needs to be verified to allow the safe operation of nuclear power plants. Austenitic stainless steel welds are inspected with ultrasound. The austenitic weld distorts, attenuates, deviates and scatters the ultrasonic beam making the inspection difficult.
    When conducting ultrasonic inspection at the power plants, the time allowed for the in- spection is short as the components are only accessible during outages. Due to the limited time and required qualifications, the inspection plan and procedure are validated before- hand. The ultrasonic method is verified using test block, but acquiring test blocks with service induced flaws is difficult. Instead, mock-ups can be used. Producing real like flaws in the mock-ups is also expensive and time consuming. Artificial flaws, like elec- trical discharge machined (EDM) notches can be used as more cheap alternatives. Simu- lation is also a possibility to verify the methods of ultrasonic inspection.
    The aim of this thesis is to study the validity of ultrasonic simulations in austenitic stain- less steel weld. An existing test block with five EDM notches is inspected and then the same procedure is carried out in a CIVA simulation. The simulation is done with smooth flaws and flaws that have surface roughness. The results of the carried out measurements are compared with the results of the simulations.
    Original languageEnglish
    QualificationMaster Degree
    Awarding Institution
    • Tampere University of Technology (TUT)
    Supervisors/Advisors
    • Vippola, Minnamari, Supervisor, External person
    • Koskinen, Tuomas, Advisor
    Award date15 Aug 2018
    Publisher
    Publication statusPublished - Aug 2018
    MoE publication typeG2 Master's thesis, polytechnic Master's thesis

    Fingerprint

    Austenitic stainless steel
    Welds
    Inspection
    Ultrasonics
    Defects
    Mockups
    Nuclear power plants
    Weldability
    Structural integrity
    Outages
    Corrosion resistance
    Power plants
    Surface roughness
    Mechanical properties
    Networks (circuits)

    Keywords

    • Ultrasound
    • austenitic stainless steel
    • weld
    • artificial flaw
    • flaw
    • defect
    • Inspection
    • NDE
    • NDT

    Cite this

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    title = "Artificial flaw simulation in ultrasonic inspection of austenitic stainless steel weld: Master's thesis",
    abstract = "Nuclear power plant primary circuit components are made from austenitic stainless steels. They provide mechanical properties combined with corrosion resistance and weldability. The structural integrity of the components needs to be verified to allow the safe operation of nuclear power plants. Austenitic stainless steel welds are inspected with ultrasound. The austenitic weld distorts, attenuates, deviates and scatters the ultrasonic beam making the inspection difficult.When conducting ultrasonic inspection at the power plants, the time allowed for the in- spection is short as the components are only accessible during outages. Due to the limited time and required qualifications, the inspection plan and procedure are validated before- hand. The ultrasonic method is verified using test block, but acquiring test blocks with service induced flaws is difficult. Instead, mock-ups can be used. Producing real like flaws in the mock-ups is also expensive and time consuming. Artificial flaws, like elec- trical discharge machined (EDM) notches can be used as more cheap alternatives. Simu- lation is also a possibility to verify the methods of ultrasonic inspection.The aim of this thesis is to study the validity of ultrasonic simulations in austenitic stain- less steel weld. An existing test block with five EDM notches is inspected and then the same procedure is carried out in a CIVA simulation. The simulation is done with smooth flaws and flaws that have surface roughness. The results of the carried out measurements are compared with the results of the simulations.",
    keywords = "Ultrasound, austenitic stainless steel, weld, artificial flaw, flaw, defect, Inspection, NDE, NDT",
    author = "Oskari Jessen-Juhler",
    year = "2018",
    month = "8",
    language = "English",
    publisher = "Tampere University of Technology",
    address = "Finland",
    school = "Tampere University of Technology (TUT)",

    }

    Artificial flaw simulation in ultrasonic inspection of austenitic stainless steel weld : Master's thesis. / Jessen-Juhler, Oskari.

    Tampere University of Technology, 2018. 76 p.

    Research output: ThesisMaster's thesisTheses

    TY - THES

    T1 - Artificial flaw simulation in ultrasonic inspection of austenitic stainless steel weld

    T2 - Master's thesis

    AU - Jessen-Juhler, Oskari

    PY - 2018/8

    Y1 - 2018/8

    N2 - Nuclear power plant primary circuit components are made from austenitic stainless steels. They provide mechanical properties combined with corrosion resistance and weldability. The structural integrity of the components needs to be verified to allow the safe operation of nuclear power plants. Austenitic stainless steel welds are inspected with ultrasound. The austenitic weld distorts, attenuates, deviates and scatters the ultrasonic beam making the inspection difficult.When conducting ultrasonic inspection at the power plants, the time allowed for the in- spection is short as the components are only accessible during outages. Due to the limited time and required qualifications, the inspection plan and procedure are validated before- hand. The ultrasonic method is verified using test block, but acquiring test blocks with service induced flaws is difficult. Instead, mock-ups can be used. Producing real like flaws in the mock-ups is also expensive and time consuming. Artificial flaws, like elec- trical discharge machined (EDM) notches can be used as more cheap alternatives. Simu- lation is also a possibility to verify the methods of ultrasonic inspection.The aim of this thesis is to study the validity of ultrasonic simulations in austenitic stain- less steel weld. An existing test block with five EDM notches is inspected and then the same procedure is carried out in a CIVA simulation. The simulation is done with smooth flaws and flaws that have surface roughness. The results of the carried out measurements are compared with the results of the simulations.

    AB - Nuclear power plant primary circuit components are made from austenitic stainless steels. They provide mechanical properties combined with corrosion resistance and weldability. The structural integrity of the components needs to be verified to allow the safe operation of nuclear power plants. Austenitic stainless steel welds are inspected with ultrasound. The austenitic weld distorts, attenuates, deviates and scatters the ultrasonic beam making the inspection difficult.When conducting ultrasonic inspection at the power plants, the time allowed for the in- spection is short as the components are only accessible during outages. Due to the limited time and required qualifications, the inspection plan and procedure are validated before- hand. The ultrasonic method is verified using test block, but acquiring test blocks with service induced flaws is difficult. Instead, mock-ups can be used. Producing real like flaws in the mock-ups is also expensive and time consuming. Artificial flaws, like elec- trical discharge machined (EDM) notches can be used as more cheap alternatives. Simu- lation is also a possibility to verify the methods of ultrasonic inspection.The aim of this thesis is to study the validity of ultrasonic simulations in austenitic stain- less steel weld. An existing test block with five EDM notches is inspected and then the same procedure is carried out in a CIVA simulation. The simulation is done with smooth flaws and flaws that have surface roughness. The results of the carried out measurements are compared with the results of the simulations.

    KW - Ultrasound

    KW - austenitic stainless steel

    KW - weld

    KW - artificial flaw

    KW - flaw

    KW - defect

    KW - Inspection

    KW - NDE

    KW - NDT

    M3 - Master's thesis

    PB - Tampere University of Technology

    ER -