Monotonic and cyclic stress-strain response of annealed 2 1/4 Cr--1 Mo steel

Abstract

The stress-strain response of isothermally annealed 2$sup 1$/$sub 4$ Cr-- 1 Mo steel under monotonic and cyclic loadings was characterized at 21 to 593$sup 0$C. Monotonic stress-strain curves were developed for uniaxial tensile loading of speciments at strain rates of 8.33 x 10$sup -5$ and 8.33 x 10$sup -6$ s$sup -1$. The cyclic stress-strain response was measured for the first 100 fully reversed strain cycles at strain ranges between 0.4 and 3.0 percent under uniaxial loading at a strain rate of 8.33 x 10$sup -5$ s$sup -1$. The effects of creep, stress-relaxation, and thermal-exposure hold periods on the cyclic stress- strain behavior were also investigated at 510$sup 0$C. Monotonic stress-strain curves were quantified using a power law relation between stress range and plastic-strain range. Cyclic hardening was observed at temperatures up to 427$sup 0$C. A mixture of initial cyclic hardening followed by later cyclic softening was seen at temperatures from 482 to 538$sup 0$C, and cyclic softening was observed at 593$sup 0$C. One measure of the cyclic stress-strain response was characterized by the ascending path of the stress-strain hysteresis loop for the tenth cycle. The reported results form part of the data base to be used by others in formulating similar general inelastic constitutive equations for analysis of 2$sup 1$/$sub 4$ Cr-1 Mo steel components. (auth