Applicability of the Master Curve method to Ultra High Strength Steels

Kim Wallin, Sakari Pallaspuro, Päivi Karjalainen-Roikonen, Pasi Suikkanen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    4 Citations (Scopus)


    Although Ultra High Strength Steels (UHSS) with nominal strengths up to 1500 MPa have been available on the market for many years, the use of these steels in the civil engineering industry is still rather uncommon. One critical point limiting the use of UHSS steels lies in their rather poorly documented fracture properties in relation to more conventional steels covered by the codes. The major concept governing the assessment of steels is the Master Curve (MC) methodology. It provides a description for the fracture toughness scatter, size effect and temperature dependence in the ductile to brittle transition region. It enables a complete characterization of brittle fracture toughness of a material based on only a few small size specimens. The method combines a theoretical description of the scatter, a statistical size effect and an empirically found temperature dependence of fracture toughness. The fracture toughness in the brittle fracture regime is thus described with only one parameter, the transition temperature T0. At this temperature the mean fracture toughness for a 25.4 mm thick specimen is 100 MPa√m. The Master Curve method as defined in ASTM E1921-13a is applicable to ferritic structural steels with yield strength between 275 MPa and 825 MPa. Very few studies have been made with respect to the applicability of the Master Curve to Ultra High Strength Steels with yield strengths in the excess of 900 MPa. This is the topic of this work. Focusing on novel directly quenched high performance steels, the applicability of the Master Curve methodology with special emphasis on the temperature dependence will be investigated. Possible improvements to the Master Curve will be proposed for further consideration.
    Original languageEnglish
    Title of host publicationASME 2015 Pressure Vessels and Piping Conference
    Subtitle of host publicationCodes and Standards
    Place of PublicationBoston
    PublisherAmerican Society of Mechanical Engineers (ASME)
    Number of pages16
    ISBN (Print)978-0-7918-5693-2
    Publication statusPublished - 2015
    MoE publication typeA4 Article in a conference publication
    EventASME 2015 Pressure Vessels and Piping Conference, PVP 2015 - Boston, United States
    Duration: 19 Jul 201523 Jul 2015


    ConferenceASME 2015 Pressure Vessels and Piping Conference, PVP 2015
    Abbreviated titlePVP 2015
    Country/TerritoryUnited States


    • high strength steel


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