Temperature And Stress Finite Element Analysis Of Slab During Continuous Casting

In the continuouse casting process,the Thermal-Mechanical behavior of casting slab has an important impact on the final product quality. Therefore, the application of mathematical analysis of the temperature and stress field of slab,which has important practical significance in continuous casting production. This paper direct internal and corner crack defects of some steel grades in the vertical-bending slab caster production process, base on the basic structure of the ccaster and process parameters, According to strand solidification heat transfer and force boundary conditions under the vertical-bending slab caster in the plant, construct two-dimensional temperature and stress finite element model.In the paper, analysis of solidification heat transfer in the slab continuous casting process of horizontal and vertical two-dimensional section respectively,and application of non-steady state heat conduction equation in slab heat transfer analysis, Finite element analysis of heat transfer in MSC.Marc used Galerkin method of weighted residuals. The influence of liquid steel caused forced convection boundary conditions and thermal properties of nonlinear changes,were taken into consideration in the solidification heat transfer model.Based on two-dimensional temperature field, consideration of the impact of nonlinear mechanical behaviour of slab at the high temperature , the contact state between slab and roller, the static pressure of liquid steel, used of the yield stress and hardening modulus determined Von Mises yield criteria, were established two-dimensional horizontal and vertical section thermal elastic-plastic stress model of slab.Finite element model mesh use the high-precision rectangular unit which aspect ratio close to 1. The solve combines temperature and elastic-plastic analysis based on the commercial Finite elements method system Msc.marc?, in which a very good use of nonlinear analysis of convergence of Newton-Rafson method was applied.Calculations of Solidification heat transfer have been given two-dimensional horizontal section temperature field under particular roll position,and the longitudinal section temperature field of the overall slab caster., Analysis of the temperature fields at the cross section of mold, bending transition zone at the earlier stage of solidification and Straightening zone at the later stage of solidification three zones in the three different drawing speed. The results show that the longitudinal cornercracks is main caused by an unreasonable amount of cooling water at mold and the foot roller zone.The appropriate objectives temperature of strand at bending and straightening zone should be combined with high-temperature mechanical properties of strand , to avoid cracks formation or worsening cracks expand of slab.Base on the Temperature field calculation results, analysis of the equivalent stress changes inner strand shell associated with solidification , both inner and outer side of the slab variation of equivalent stress distribution, as well as the contact load state between slab and roller.The results show that outer side of the slab at bending transition zone and inner side of the slab at straightening zone have maximum equivalent stress. Prophase of secondary cooling zone under low drawing speed,Both inside and outside the slab in the corner have a greater stress concentration area at bending transition zone, the stress concentration area will be move inward along with the solidification progresses.Assessment of fixed constraint of contact approach in the horizontal two dimensional stress model, Results show that calculations are consistent with Normal contact force load approach.Contrast the equivalent stress value of slab centre line across the width between horizontal and vertical two dimensional stress model , Results show that application of the vertical two dimensional stress model analysis of the Force of the overall slab has more advantages.