Constitutive equations for modeling non-Schmid effects in single crystal bcc-Fe at low and ambient temperatures

• A crystal plasticity framework is developed for modeling non-Schmid effects in bcc crystals.
• Decay of the non-Schmid stresses with increase in temperature is modeled.
• Constitutive equations are developed for decay of the non-Schmid stresses with inelastic deformation.
• The stress–strain response and hardening behavior of bcc-Fe at 298 K is modeled and fit to experiments.
• Orientation- and temperature-dependent yield stress and tension–compression asymmetry of bcc-Fe is modeled.

Constitutive equations are developed for single crystal bcc-Fe at low and ambient temperatures based on the assumption that non-Schmid effects are primarily influential on orientation dependence and tension–compression asymmetry of the initial yield stress. Temperature dependence of the non-Schmid parameters is extracted from a fit to available experimental data. Constitutive models are also developed for the decay of the influence of non-Schmid stresses with inelastic deformation. These equations are used in a dislocation density-based crystal plasticity framework to model the mechanical behavior of bcc-Fe. The stress–strain response is modeled and fit to the experimental data at 298 K. Orientation-dependent yield stress and tension–compression asymmetry simulations are compared to available experiments.