Uniaxial cyclic deformation behaviour of SA 333 Gr 6 piping steel at room temperature

摘要

The paper reports the cyclic deformation behaviour of SA333 Gr 6 piping material subjected to room temperature stress and strain controlled cyclic tests. Cyclic straining trends at constant total strain amplitude at each of the three different strain levels tested have shown initial softening prior to attaining cyclic saturation. Ratcheting behaviour under stress-controlled conditions has been studied at different stress ratios and stress rate combinations. The ratcheting experiments have shown that strain accumulation depends on both stress rate and stress ratio. The formation and propagation of cyclic Liiders bands has been attributed to play a significant role in determining the cyclic deformation characteristics under stress and strain controlled conditions. The ratcheting results have been qualitatively explained in terms of a synergistic interaction between stress rate and stress ratio during cyclic softening. It has been attempted to describe the experimental data from the various tests using empirical equations.