Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel

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    2 Citations (Scopus)

    Abstract

    Standardised methods for the assessment of hydrogen cracking risk are mostly developed for HAZ cracking cases, where cracking often occurs as root cracking. The applied experiments are therefore usually single-pass cracking tests. For multiple-pass welding, and when the cracking sensitivity of weld metal dictates the required preheat, European standards do not give reliable guidance on how to assess the need of preheat. Standard EN 1011-2 considers the possibility of weld metal cracking, however, it does not provide the user with a validated methodology for the calculation of the actual level of 'safe' preheat temperature. The suitability of a given standard procedure, or calculation method, for multipass welds therefore has to be investigated on case by case basis. This paper is concerned with the assessment of required preheat/interpass temperature for the avoidance of hydrogen cracking in matching type multipass weld metal in a 2.25%Cr-1.0%Mo-0.25%V boiler steel using experimental and numerical methods. The applied methods were: (i) EN 1011-2 Method, (ii) Crack no crack diagram method developed by VTT, and (iii) deep-notch Implant test based analytical method developed by Osaka University and VTT. Necessary precautions for safe welding are given. Recent developments in numerical modelling of hydrogen diffusion in multipass welding are discussed.
    Original languageEnglish
    Title of host publicationBALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2
    PublisherVTT Technical Research Centre of Finland
    Pages393-407
    ISBN (Electronic)951-38-6294-1
    ISBN (Print)951-38-6293-3
    Publication statusPublished - 2004
    MoE publication typeB3 Non-refereed article in conference proceedings
    EventBALTICA VI - Life Management and Maintenance for Power Plants - Helsinki-Stockholm, Finland
    Duration: 8 Jun 200410 Jun 2004

    Publication series

    SeriesVTT Symposium
    Number234
    ISSN0357-9387

    Conference

    ConferenceBALTICA VI - Life Management and Maintenance for Power Plants
    CountryFinland
    CityHelsinki-Stockholm
    Period8/06/0410/06/04

    Keywords

    • ProperTune

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  • Cite this

    Nevasmaa, P., Laukkanen, A., & Häkkilä, J. (2004). Evaluation of weld metal hydrogen cracking risk in a 2.25Cr-1Mo-0.25V-TiB (T24) boiler steel. In BALTICA VI - Life Management and Maintenance for P ower Plants. Vol. 2 (pp. 393-407). VTT Technical Research Centre of Finland. VTT Symposium, No. 234 http://www.vtt.fi/inf/pdf/symposiums/2004/S234.pdf