STP1372: Fatigue Crack Growth Thresholds Measurements in Structural Materials

    Lindström, R
    Researcher, section head, and technical director, Studsvik Material AB, Nyköping,

    Lidar, P
    Researcher, section head, and technical director, Studsvik Material AB, Nyköping,

    Rosborg, B
    Researcher, section head, and technical director, Studsvik Material AB, Nyköping,

    Pages: 11    Published: Jan 2000


    Abstract

    Fatigue crack growth thresholds and da/dN-data at low ΔKI-values (<10 MPa√m) have been determined for type 304 stainless steel, nickel-base weld metal Alloy 182, nickel-base metal Alloy 600, and low-alloy steel in air at ambient temperature and in high-temperature water and steam. The stainless alloys have been tested in water with 0.2 ppm O2 at 288°C and the low-alloy steel in steam at 286°C. The fatigue crack growth threshold was defined as the ΔKI-value resulting in a crack growth rate of 10-7 mm per cycle. The measured fatigue crack growth thresholds (at frequencies from 0.5 to 20 Hz) are quite similar independent of the material and the environment.

    A relatively inexpensive and time-saving method for measuring fatigue crack growth thresholds, and fatigue crack growth rates at low ΔKI-values, has been used in the tests. The method is a ΔKI-decreasing test with constant KIMax.

    Keywords:

    fatigue crack growth rates, fatigue crack growth thresholds, DC potential drop, type 304 stainless steel, Alloy 182, Alloy 600, low-alloy steel, air, high-temperature water


    Paper ID: STP13445S

    Committee/Subcommittee: E08.06

    DOI: 10.1520/STP13445S


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