INELASTIC STRESS-STRAIN RESPONSE OF 2-1/4CR1MO STEEL UNDER COMBINED TENSION-TORSION AT 600-DEGREES-C

The results of the third-phase activity of the Subcommittee on Inelastic Analysis and Life Prediction of High Temperature Materials, JSMS, are summarized in this series of papers. As the first part, the evaluation of inelastic constitutive models under plasticity-creep interaction conditions is presented in extension of the previous report of the phase 2 activity. Seven types of experiment were performed under multiaxial loading of tension and torsion with normalized and tempered 2 1/4 Cr-1Mo steel at 600 degrees C: (i) step-up/down creep, (ii) uniaxial tension with strain rate change, (iii) cruciform stressing, (iv) biaxial mechanical ratcheting, (v) cyclic torsion, (vi) in-phase cyclic straining and (vii) out-of-phase cyclic straining. The experimental results of these benchmark tests are compared with the simulated results by seven types of constitutive models to evaluate their accuracy in simulating the experimental behaviour of the material.