The mechanical threshold stress constitutive-strength model description ofHY-100 steel

A generalized three-term mechanical threshold stress (MTS) strength model d escription, considering athermal, thermal, and strain-hardening contributio ns to flow stress, is employed to characterize the constitutive stress-stra in response of HY-100 steel. Aspects of the MTS framework pertinent to Unit ed States Navy HY steels are discussed, and a calibration methodology is pr esented for determining MTS strength model parameters. In addition, a linea r strain-hardening modification to the existing structure-evolution express ion (flow-stress saturation) is proposed to better describe the large-strai n strain-hardening behavior. Polycrystalline plasticity calculations sugges t that the linear-lice hardening behavior is a consequence of deformation-p ath-dependent texture evolution. Calculation results are applied to MTS mod el stress-strain predictions and, in part, help explain the differences bet ween compression and torsion test data.