Unified Modelling of Flow Stress and Microstructural Evolution of 300M Steel under Isothermal Tension

Constitutive models that reflect the microstructure evolution is of great significance to accurately predict forming process forging. Through thermal tension 300M steel under various temperatures (950~1150 °C) and strain rates (0.01~10 s−1), material flow evolutions were investigated. In order describe both exponential hardening phenomenon at a higher temperature, softening due recrystallization lower constitutive model considering was proposed based on Kocks–Mecking model. It found stress-strain curve be in work-hardening stage could improve prediction precision. The average error 2.43% (3.59 MPa), showing more precise than modified Arrhenius kinetics grain size also constructed. This work enabled curves with accuracy, broadened applicable range