Study On The Computer Simulation And Process Optimization Of Low Carbon Steel In Hot Bar Rolling

In recent years, the steel is widely used with the continuous development of China’s economic construction. The rolling technology is one of the main material molding methods. In the iron and steel industry, more than 90% steels were produced by the means of rolling technology. They are widely used in those industries which have important impacts on our economy, such as cars, buildings, energy, transportation. It’s needed to develop some new crafts to improve the quality and mechanical properties of the product in order to develop new markets. By now, using the computer to simulate the entire process of rolling is a new method. It can forecast the material’s manufacturability and quality. For the above reasons, this paper will take research on 20 A steel’s dimensional accuracy in its molding process, mechanical properties and quality, and some other issues. The following are those works done:(1) the theoretical study about 20A’s constitutive model and dynamic recrystallization model is done. Its stress-strain curve is got by carry the experiment on G1500-leeble, and analyse the rules between deformation conditions and the flow stress. Then its constitutive model under high temperature and dynamic recrystallization model are buided, it will help to simulate and analyze the rolling prosses.(2) The roll groove is designed based on the theoretical data provided by factories and the theories of designing the rolling holes.(3) The secondary developent of materials database in Deform-3D is also one of my works. Its three-dimensional mode is buided by UG. The material’s theoretical model and its thermal properties are added in the database. The three-dimensional mode is based on the designed roll pass.(4) To find the optimal process parameters, orthogonal experiments are carried out. Besides, finite element simulation is also used to analyze the forming process under different conditions of rolling billet and forecast the stress field during hot rolling stage, equivalent strain field, temperature field, the metal flow and grain size evolution.(5) Finally, experiment is carried out to verify the process. The Sampling of 20 A steel which is produced under the optimal plan is used to test its properties: overall size, hardness, and surface morphology and microstructure. The results are compared with the simulation.The results shows that finite element simulation is viable to simulation the rolling process, optimize the rolling parameters and groove, and shorten development cycle, even reduce the production costs and risk of product development, provide a good foundation for rolling mills to improve product quality and develop scientific rolling process.