Strain rate continuity in 304 stainless steel during stress rate change tests

Stress rate change experiments have been used to assess the contribution of mechanical activation of dislocation glide to the inelastic deformation of 304 stainless steel. These experiments were conducted in a servohydraulic testing machine by loading at stress rates from 5 to 40 MPa/s to a constant stress between 250 and 450 MPa. An extrapolation method was developed to determine the inelastic strain rates just prior to and just after the transition in stress rate. The results of these experiments demonstrate that the inelastic strain rate is continuous in this material through a transition in stress rate. These findings, in contrast to previously published results, indicate that mechanical activation does not occur under these testing conditions.