STP1329: Fracture Toughness Test on Precracked Charpy Specimens in The Transition Range for Linde 80 Weld Metals

    Hour, KY
    Principal Engineer, Babcock & Wilcox Company, Lynchburg Research Center, Lynchburg, VA

    Yoon, KK
    Principal Engineer, Babcock & Wilcox Company, Lynchburg Research Center, Lynchburg, VA

    Pages: 23    Published: Jan 1998


    Abstract

    The emphasis of this paper is to summarize the experience gained from an on-going B&W Owners Group test program on precracked Charpy specimens in accordance with the proposed ASTM Standard “Test Method For the Determination of Reference Temperature, T0, for Ferritic Steels in the Transition Range”. Both unirradiated and irradiated precracked Charpy specimens were tested in three-point bending, reconstituted, and retested to establish the reference temperature, T0, for various Linde 80 weld metals. Tests results were compared to those generated from an ORNL test program on Linde 80 weld metals and B&W Owners Group compact tension specimens tested in the transition range to determine the validity of using precracked Charpy specimens. Master curves were constructed for Linde 80 weld metals and then compared to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code KIc reference fracture toughness curve. The ASME lower-bound KIc curve is positioned relatively conservatively. The results indicate that the current practice of Code fracture toughness for low upper-shelf weldments is conservative. Experience gained on preparation of specimens, precracking technique, selection of test temperature, test technique, and data analysis is summarized in this paper.

    Keywords:

    fracture toughness, fracture mechanics, Linde 80 weld, reactor vessel, transition range, master curve, neutron embrittlement, reconstituted Charpy specimens, reactor vessel surveillance program


    Paper ID: STP37991S

    Committee/Subcommittee: E10.02

    DOI: 10.1520/STP37991S


    CrossRef ASTM International is a member of CrossRef.