Research on creation and application of material models in the rolling process of medium and heavy plate leveler
Mechanical properties model of moderate/high temperature material affects leveling parameters setting. This article establishes the model as well as self-studying in rolling process and simplex optimizes the formulation of material model's deformation resistance. The model is established through this process which has a higher application in the actual production.
Material Model Describing Cyclic Elastic‐Plastic Deformation of Roller Levelling and Straightening Processes
The presented material model describes the elastic‐plastic stress‐strain course of cyclic tension‐compression deformation with variable amplitudes. The result is a hysteresis curve. Each hysteresis curve consists at maximum of three parts. Part I starts on a linear course originating from elastic strain or elastic recovery and ends at a defined point N. When the strain runs past this point, part II then follows as a non‐linear function where the superposition of a logarithmic function with a parabola proved to be in good coincidence with the real material behaviour. When the strain reaches a point T, linear hardening begins as part III. For the application of the model in practice, a file of data from special tests with cyclic tension‐compression deformations is necessary. The material model can be applied as a subsystem in a roller straightening process model. It has been successfully used in practice. The detrimental residual stresses were significantly reduced as well as the straightness of the rails was improved.
Numerical Simulation of Induction Heating Process of Continuous Casting Slab
Compared with traditional blazing furnace, the Continuous Casting-Direct Rolling is an advanced manufacturing steel technology, which can reduce energy waste, decrease pollution and enhance efficiency. The characteristics of steels during induction heating are complex, the change of material properties with temperature makes exact analysis methods very difficult to implement. Therefore, a powerful computer aided numerical tool (i.e., finite difference analysis) is selected to numerically model the induction heating process in this paper. The mathematic model coupling with electromagnetic field and thermal field was established, and it was solved by finite difference method (FDM), thus the slab temperature distribution and its variation with time were obtained, and the characteristics in whole induction heating process were studied. To validate the program feasible, the results were evaluated and compared with experiment results, which showed that the simulation results are reliable and effective. The skin effect in heating process from the two results was studied and demonstrated, the temperature change caused by different parameters such as the induced power intensity and the corner radian were also presented, which indicate that the slab temperature can be heated uniformly through adjusting these parameters, thus the continuous casting slab can meet the rolling requirement.