Ratcheting deformation of advanced 316 steel under creep-plasticity condition

A series of mechanical ratcheting tests under tension-torsion biaxial conditions has been conducted with an advanced 316 stainless steel at 923 K. Accumulation of torsional ratcheting strain was measured with a cyclic axial strain ranges of 0.005-0.02, cyclic axial strain rate of 10^-5 to 10^-3 S^-1 and steady torsional stresses of 24.5/(SQRT)3 to 73.5/(SQRT)3MPa. The accumulation of ratcheting shear strain is mainly affected by the cyclic axial strain range and the steady shear stress, and increases with an increase of both these parameters. A simple evaluation of the accumulation of ratchet strain is proposed. Although this procedure is based on the separation of creep and plasticity and uses experimental data to skip the plasticity analysis, the obtained results show good agreement with the experimental results. © 1999 Elsevier Science S.A. All rights reserved.