Recrystallization behavior of a Nb-microalloyed steel during hot compression

• Published in: Applied mathematical modelling Vol. 35; no. 7; pp. 3268 - 3275
• Main Authors: Bao, Siqian, Zhao, Gang, Yu, Chibin, Chang, Qingming, Ye, Chuanlong, Mao, Xinping
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Inc 01.07.2011; Elsevier
• Subjects: Applied sciences; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Creep; Cross-disciplinary physics: materials science; rheology; Dynamic recrystallization (DRX); Exact sciences and technology; Fundamental areas of phenomenology (including applications); Inelasticity (thermoplasticity, viscoplasticity...); Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nb-microalloyed steel; Physics; Solid mechanics; Static recrystallization (SRX); Structural and continuum mechanics; Treatment of materials and its effects on microstructure and properties; Zener–Hollomon parameter; Nb-microalloyed steel; Zener–Hollomon parameter; Dynamic recrystallization (DRX); Static recrystallization (SRX); Creep; Yield criterion; Compressive testing; Thermomechanical properties; Activation; Dynamic loads; Regression analysis; High temperature; Experimental study; Empirical model; Zener-Hollomon parameter; Microalloyed steel; Recrystallization; Modelling; Kinetics; Semiempirical method; Strain rate
• ISSN: 0307-904X
• DOI: 10.1016/j.apm.2011.01.024

Using a Thermecmastor-Z hot simulator, dynamic recrystallization (DRX) and static recrystallization (SRX) behavior of a Nb-microalloyed steel was investigated by single-hit compression tests and double-hit compression tests, respectively. The experimental results show that DRX will more easily occur at higher deformation temperature and lower strain rate. The deformation activation energy and stress exponent for the Nb-microalloyed steel are calculated to be 379.29 ± 23.56 kJ/mol and 5.76 in temperature range of 950 °C to 1100 °C by regression analysis, respectively. Furthermore, a semi-empirical model is developed to identify the peak stress and strain for DRX. It is found that SRX kinetics follows Avrami’s law, and the softening fraction predicted by the model agrees well with experimental results.