Simulation of non-isothermal recrystallization kinetics in cold-rolled steel

Abstract

In this work, a model has been developed to determine thermal and microstructural events during non-isothermal annealing of rolled carbon steels. In the first place, the process of cold rolling under both symmetrical and asymmetrical conditions was mathematically modeled employing an elastic-plastic finite element formulation to define the distribution of plastic strain and internal stored energy. In the next step, two-dimensional model based on cellular automata was generated to assess softening kinetics in annealing treatment. At the same time, a thermal model based on Galerkin-finite element analysis was coupled with the microstructural model to consider temperature variations during heat treatment. The impact of different parameters such as heating rate, annealing temperature, and initial microstructures were all taken into account. To validate the employed algorithm, the predictions were compared with the experimental results and a reasonable agreement was found. Accordingly, the simulation results can be employed for designing a proper mechanical-thermal treatment to achieve the desired microstructure as well as mechanical properties under practical processing conditions.

Microstructural Changes During Static Recrystallization of Austenitic Stainless Steel 304L: Cellular Automata Simulation

“…Note that the recrystallized grains grow until they impinge with the other moving grain boundary, or softening fraction reaches 0.95. The growth velocity consists of grain boundary mobility associated with exponential behavior and driving pressure for growth which are calculated as a combination of the curvature and the deformation energy in each cell [27,28]. So, the velocity of moving boundary can be defined as:…”

“…After that, Vickers hardness measurements were taken to define the mechanical properties and softening fraction occurred during heat treatment. The fraction of softening was computed as [28,31].…”