A Flow Stress Model of 300M Steel for Isothermal Tension

To investigate the effect of hot working parameters on the flow behavior of 300M steel under tension, hot uniaxial tensile tests were implemented under different temperatures (950 degrees C, 1000 degrees C, 1050 degrees C, 1100 degrees C, 1150 degrees C) and strain rates (0.01 s(-1), 0.1 s(-1), 1 s(-1), 10 s(-1)). Compared with uniaxial compression, the tensile flow stress was 29.1% higher because dynamic recrystallization softening was less sufficient in the tensile stress state. The ultimate elongation of 300M steel increased with the decrease of temperature and the increase of strain rate. To eliminate the influence of sample necking on stress-strain relationship, both the stress and the strain were calibrated using the cross-sectional area of the neck zone. A constitutive model for tensile deformation was established based on the modified Arrhenius model, in which the model parameters (n, alpha, Q, ln(A)) were described as a function of strain. The average deviation was 6.81 MPa (6.23%), showing good accuracy of the constitutive model.

Automated summary

The study investigated the flow behavior of 300M steel under tension through hot uniaxial tensile tests at different temperatures and strain rates. Compared to compression tests, tensile flow stress was higher and ultimate elongation of 300M steel was influenced by temperature and strain rate. A constitutive model based on the modified Arrhenius model showed good accuracy with an average deviation of 6.81 MPa.