Cellular Automata Simulation Of Austenite To Ferrite Transformation In Low Carbon Steel

Steel material is an indispensable structural material in national economic construction,especially the development of advanced steel materials has become a hot topic in academia and industry in recent years.During a hot-working process,the austenite grains will grow by subjecting steel material to above critical temperature.And then cooled to room temperature,the tissue transformation of the austenite phase to ferrite phase occurs.However,because of most mechanical components working at room temperature,the mechanical properties of steel are ultimately determined by the continuous cooling of austenite.Therefore,it is very important to study austenite grain growth and continuous cooling austenite-ferrite phase transition.Due to the traditional experiment can't observe microstructure evolution process in real time,so this article will study high temperature austenitic grain growth phenomenon and austenitic-ferritic phase transformation in continuous cooling process with cellular automata simulation.The main research contents of this paper include the following parts:(1)A cellular automata model has been developed to simulate the austenitic grain growth at high temperature.In order to study organization evolution process,three different temperature on the influence of the austenitic grain growth process were simulated.(2)In order to describe the austenite to ferrite transformation,a cellular automata model combining with ferrite nucleation model and growth model was developed.When dealing with the abnormal concentration of solute,an effective method for calculating austenitic/ferrite phase interface cell solute concentration was proposed.Using austenitic grain growth process of parent organization as input,and setting the initial conditions,the austenitic-ferritic phase transformation in continuous cooling process has been simulated.The results showed that the growth of ferrite was controlled by the interfacial migration and the diffusion of C atoms.In order to study the microstructural behavior and phase transformation kinetics,three different parent phase grain size and cooling rate were simulated.(3)On the basis of the previous simulation,the austenite-ferrite phase transition microstructure evolution simulation system was developed independently.The system displayed austenite grain growth and austenite-ferrite phase transformation simulated results on the onstage contact surface in real time,and realized dynamic observation of microstructure evolution.