Modeling the hot flow behavior of a Fe–22Mn–0.41C–1.6Al–1.4Si TWIP steel microalloyed with Ti, V and Nb

Abstract

Cite this article as: I. Mejía, F. Reyes-Calderón and J.M. Cabrera, Modeling the hot flow behavior of a Fe-22Mn-0.41 C-1.6Al-1.4Si TWIP steel microalloyed with Ti, V and Nb, Materials Science & Engineering A, http://dx. AbstractThe present research work analyses the influence of Ti, V and Nb microalloying elements on the hot flow behavior of a high-Mn TWIP (Twinning Induced Plasticity) steel. For this purpose, flow curves were obtained by uniaxial hot compression tests performed at four strain rates (10 -1 , 10 -2 , 10 -3 and 10 -4 s -1 ) and three temperatures (900, 1000 and 1100 ºC). The models of Estrin, Mecking and Bergstrom; Avrami and Tegart, and Sellars were applied to determine the hot working constants used to derive the constitutive equations describing the flow curves.The analysis of modeling parameters of the hot flow curves shows that Ti, V and Nb additions to TWIP steel generated slight increase in the peak stress ( p ), retardation of the dynamic recrystallization (DRX) onset, particularly at low temperature, and decrease in the activation energy required to recrystallization (Q t ). Likewise, the softening effect promoted by DRV and DRX was more evident at high temperatures and low strain rates. On the other hand, the resulting deformed microstructures, analyzed by the SEM-EBSD technique, showed that the most important refining effect on recrystallized austenitic grain was in the presence of V and Ti. The good agreement between the experimental and predicted hot flow curves demonstrated that the developed constitutive equations predict with reasonable accuracy the hot flow behavior of the studied TWIP steels.

Microstructural and Mechanical Characterization of Ti‐Containing Twinning‐Induced Plasticity Steel Welded Joint Produced by Gas Tungsten Arc Welding Process

“…In contrast, different research works refer to the excessive equiaxial grain growth in the HAZ of TWIP steels, using different fusion welding processes such as laser and resistance spot welding . It is worth highlighting that although the HAZ of TWIP‐Ti steel showed grain growth, this growth was not excessive, which can be associated to the low heat input used in the semiautomatic GTAW process and the grain growth inhibition effect of Ti as a microalloying element …”

“…It is well known that Ti allows the formation of precipitates at high temperatures, which can inhibit grain growth . Mejia et al showed the effect of Ti as a grain refiner in TWIP steels, reporting that a TWIP steel microalloyed with Ti exhibited a grain size of 63 ± 32 μm, whereas the TWIP steel without a microalloying element showed a grain size of 104 ± 23 μm after austenitization at high temperatures. Most probably the present annealing temperature was not enough to completely dissolve the TiN particles, and therefore some abnormal grain growth took place.…”

Enhancement of grain structure and mechanical properties of a high-Mn twinning-induced plasticity steel bearing Al–Si by fast-heating annealing

“…where U and Ω are the hardening and softening parameters, respectively. Both parameters are assumed to be independent of the applied strain [30]. Thus, the dislocation density can be obtained by integration of Eq.…”

Characterization of Flow Behaviors by a PSO-BP Integrated Model for a Medium Carbon Alloy Steel

“…A large number of studies have shown that physical models are widely used to describe the complex flow behaviors of metals, such as Johnson-Cook type [5,6], Arrhenius type [7,8], Bergstrom type [9], Kolmogorov-Johnson-Mehl-Avrami type [10], etc. The physical model is based on a set of parameters that can be expressed as a function of forming temperature, strain, and strain rate.…”