STUDYING THE HOT WORKING CHARACTERISTICS AND DYNAMIC RECRYSTALLIZATION BEHAVIOR OF CONVENTIONAL LOW CARBON STEEL DURING IN-LINE STRIP PRODUCTION PROCESS

摘要

Thin slab casting and direct rolling (TSDR) technologies are one of the most developing steel making processing methods to maintain steel as a major material in industrial applications. Inline Strip Production (ISP) which is one of TSDR routes conditions are simulated in laboratory scale using Thermae and torsion tester. The activation energy for deformation (Q_(def)) and material parameter (n) of conventional low carbon steels with different contents of nitrogen are determined from Zener-Hollomon parameter relationships. The critical stresses and strains for the onset of dynamic recrystallization during roughing section in ISP process are calculated using method given by Najafizadeh and Jonas. They have proposed a third order polynomial equation to fit the strain hardening rate (θ) versus flow curve (σ), and the critical stress for the onset of dynamic recrystallization is given by the simple relationships. The relationships between several hot deformation parameters and Zener-Holomon parameter will be discussed.