STP942: Cyclic Stress-Strain-Time Response of a 9Cr-1Mo-V-Nb Pressure Vessel Steel at High Temperature

    Swindeman, RW
    Metallurgist, Oak Ridge National Laboratory, Oak Ridge, TN

    Pages: 16    Published: Jan 1988


    Abstract

    Data are presented that describe the behavior of a 9Cr-1Mo-V-Nb steel under conditions of constant and cyclic loading at temperatures from 25 to 600°C. The general features of hardening under monotonic and cyclic strains are presented. Creep data for temperatures in the range 500 to 650°C and times to 10 000 h are correlated by a creep law that is used in conjunction with hardening data to construct isochronous stress versus strain curves applicable to monotonic and cyclic loading. Simple rules for hardening and recovery are postulated and used to estimate the time dependent behavior after mechanically and thermally induced reversal strains. Data from relaxation, partially restrained creep, and two-bar creep ratchetting experiments are presented, and the estimated response is compared with the test data. It is shown that simple concepts of strain hardening and reversed strain softening are adequate for estimating the material behavior under most of the loading conditions that were examined.

    Keywords:

    elevated temperature, cyclic behavior, creep, high temperature design, relaxation, thermal cycling


    Paper ID: STP24478S

    Committee/Subcommittee: E08.05

    DOI: 10.1520/STP24478S


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