Development Of Simulation Software And Numerical Analysis On Secondary Cooling Zone In Thin Slab Continuous Casting

The technology of thin slab continuous casting has greatly been evoloved in recent years. As an important technology in the continuous casting process, the secondary cooling process plays an important role in producing slab with high quality, so it's significant for the heat transfer and stress analysis in the solidification process of secondary cooling zone for thin slab continuous casting. According to the characteristic of thin slab continuous casting, expoitation of all-purpose simulation software and analysis of solidification process along with stress states in thin slab secondary cooling casting has been studied in this paper.According to structure and production process of the casting machine, the vertical and transverse boundary conditions of the mold and secondary cooling zone has been studied .Meanwhile, the mathematical model of heat transfer for the thin slab of continuous casting process was established and difference numeric analysis has been adopted to solve mathematical model. According to the features of the funnel-shaped mold thin slab, model make mold total heat transfer and the change law of heat flux are same, Realizing generalization of the heat transfer software for thin slab secondary cooling casting. At the sametime, physical property parameter of the relative steel grade is confirmed.According to the character of the thin slab caster, the all-purpose simulation software for thin slab secondary cooling casting has been developed by Visual Basic. We have considered the distinguishing feature of transverse non-uniform and jet density superposition of secondary cooling zone thin slab continuous casting in software.It can simulate the change of the transverse surface temperature of the thin slab and inhomogeneity.It can optimized the nozzle collocation and simulate morphology of the shell thickness.The main function of the software is to simulate the process of solidification heat transfer, analysis growth of the solidified shell and process simulation data.Combined with the practical process of the thin slab caster, the software has been adoped to calculate the solidification heat transfer. The forming and temperature distribution law of casting sections and the thickness of the shell has arrived, which is accordant with the practical process and metallurgic guideline.According to the boundary conditions of the mathematical model developed in the all-purpose simulation software, a 2D finite element heat transfer simulation model was developed for the thin slab continuous casting process with commercial software MSC.Marc, and the solidification process was simulated. The results of the Marc were compared and analysed with the results of all-purpose simulation software. Analysis showed surface temperature and shell thickness of thin slab simulated with all-purpose simulation software and Marc are almost the same. So the reliability of the all-purpose simulation software and its guiding significance for the actual production were validated.Based on mathematical mold of the secondary solidification process of thin-slab continuous casting which is applied with Marc software, combined with the thermal elastic-plastic stress mold theory, temperature field of Marc software has been calculated. Analyzing the stress distribution of cross section obtained by the numerical simulation, the result shows that the larger stress appeared on the surface of wide surface inner arc and the less stress in the internal and surface of corner for thin slab.With the increasing of casting speed, equivalent stress value inside becomes bigger. The equivalent stress value of roll contact region is bigger than that of non-roll contact region at the same casting speed. The crack index in different place of the thin-slab has been analyzed during continuous casting process.