Grain Growth And Recrystallization Simulation Of LZ50 Steel Based On Cellular Automata Method

As one of the key parts of the train,the quality and performance of the train axle is directly related to the safety of the train. While in the thermoplastic forming process of axle production, the microstructure and grain size are important parameters to evaluate the forming properties. With the changing of its external shapes, the grain size of internal microstructure also changes accordingly. With the constantly development of the hot processing technology in materials, more attention has been paid to the evolution of the internal microstructures of the materials. LZ50 steel, as a common medium carbon steel, is widely used in the production of axle. In this paper, LZ50 steel was used as the research object, and a cellular automata model was established in its austenite grain growth period, when forged in the heating process. In the process of simulation, the energy conversion mechanism and data visualization methods were combined together, and the internal structure and the morphology in the high-speed forging process of LZ50 steel was simulated dynamically. At the same time, the evolution in the internal grain morphology of the LZ50 steel at different temperatures and holding times was discussed in detail, and the accuracy of CA simulation method was verified, further by experimental research, the grain growth rules were analyzed, and the relevant grain growth model was also established. In addition, the influence in the final grain size was discussed by setting different parameters at the single and double pass compression. The microstructure grain recrystallization behavior and mechanism of LZ50 steel were studied under the isothermal compression condition, by analyzing the experimental results, the corresponding model of static recrystallization and sub-dynamic recrystallization model was established. In summary, the numerical simulation, physical simulation and experimental study was combined in this dissertation, to research the grain growth and recrystallization behavior of the LZ50 axle steel in high-speed forging process, related numerical model was also established in detail, which provides a theoretical basis for the forging of LZ50 steel axle.