Prediction Of Microstructure And Properties Of Rolling Process Based On ABAQUS Secondary Development

Currently, ABAQUS of finite element software has been widely used in thermal processing industry with metal material, due to the defect that hatamacroscopic and microscopic constitutive model failed to establish the mechanism for high-strength low-alloy steel Q345 B with simulation of hot-rolling process, based on this study elastoplastic theory and mixed reinforcement theory, Considering precision defects of organization performance prediction in actual strip rolling process, based on real stress-strain mathematical model of the dynamic recrystallization model and microstructure model in rolling process of low alloy steel, and by VUMAT and USDFLD data interface, based on the finite element software ABAQUS, there is a secondary development research for material subroutine and its microstructure model.Finally, it is verification of simulation by Q345 B strip hot rolling process.The reserch covers the following three stages:Firstly,this paper puts to use the stress-strain mathematical model of dynamical recrystallization with suiTab. for low alloy steels. Based on the ABAQUS software platform, with the help of its interface, there is the realization of two development of VUMAT user material subroutine by the application of elastoplastic stress strain increment theory and the mixed hardening model, which updates stress with using the method of tangential radial return forecast.Secondly, during the process the metal material not noly occurs softening of dynamic recrystallization but also occurs softening of static recrystallization and sub dynamic recrystallization, at the same time it is to accompany by changes of microstructure and phenomena of grain growth, which plays the vital role in the final properties of austenitic evolution for the strip rolling. By deriving the explicit expression of the microstructure prediction model, this paper is to write the austenite recrystallization function by the Fortran language, in which call in the VUMAT user material subroutine,and writing USDFLD user subroutine is to realize two development of austenite grain growth model. The austenite microstructure prediction model can analyse the changes of microstructure during the strip hot-rolling.Finally, relying on the before and after treatment platform of ABAQUS and the nonlinear solution platform of ABAQUS, it is modelling for the strip and roller, assembly, finite element modeling and finally submitting the job by choosing.for file. And then it has the macro and micro thermodynamic simulation in hot-rolling process for Q345 B. Comparative analysis for the data of process simulation and industrial test data validated high prediction accuracy for the model, thus VUMAT subroutines and USDFLD subroutine provides a theoretical basis for the preparation of hot rolling strip.By comparative analysis of simulation results in ABAQUS post-processing extraction and industrial test data, based on the hybrid recrystallization mechanism, finite element calculation results is closer to the measured values, and anastomotic degree is high, which verified that the model forecast precision is higher; By the change rule research of austenite grain size,and by the analysis of the degree of refinement, it can adjust the finish rolling temperature, rolling speed and it can set up reasonable reduction to achieve good product organization performance and it provides the basis. Based on the model developed VUMAT subroutines and USDFLD subroutine provide theoretical basis for the preparation technology of HSM.