Flow Behavior and Metallurgical Phenomena of Micro-alloy Steel Under Elevated Temperature Conditions

The hot flow behavior of 5CT micro-alloy steel was investigated under high temperatures of 900 to 1100 degrees C and strain rates of 0.001 to 1 s(-1). The experiments displayed the complex stress behaviors in which the flow curves exhibited an obvious softening mechanism during deformation as single-peak and multi-peak curves. Microstructural analyses of the experimental steel revealed that dynamic recrystallization (DRX) was the primary softening mechanism during hot deformation, especially at low strain rates emerging as cyclic DRX in the multi-peak stress-strain curves. The constitutive equation was established based on the strain-compensated Arrhenius model, considering the relationship between material constants of the equation and true strain by a sixth-order polynomial. The flow behavior predicted by the developed model delineated a precise prediction of complex flow stress during hot working conditions.