Simulation Study Of Solidification Process And Solidification Structure Of Continuous Casting

Whether the final molding of steel has a defect in or not a considerable extent by the impact of the quality of billet,and the quality of billet is affected by the solidification process and microstructure of molten steel.So it is very necessary to study the solidification process and microstructure of the billet.By computer numerical simulation cannot be subject to the field process,only a small amount of process conditions to be able to use numerical simulation to obtain more information than the production experiment,so as to improve the production process technology.The thermal mechanical coupling simulation,the steady state simulation of the slab and the simulation of the solidification structure were designed,based on No.45 billet process as the simulation object.Through the analysis of the thermal mechanical coupling of the billet in the mold,the temperature,solidification and stress distribution of the billet were mastered.Corned by the cooling strength of the largest,the first solidification in the mold,the mold temperature is the lowest,the maximum stress.,the influence of casting temperature and casting speed on billet was simulated.The influence of pouring temperature on the temperature and stress of billet is small.While the change of casting speed affects the surface temperature of billet and the stress of shell.In the steady state simulation,the solidification rule of slab in the whole continuous casting process is analyzed,and the length of liquid phase hole and the position and size of paste zone are determined.The influence of secondary cooling strength,casting temperature and casting speed on the impact strength was also analyzed.With the increasing of the second cold strength,the length of liquid point and paste zone became shorter and the position of paste zone was far away from the meniscus.With the increasing of pouring temperature,the longer the phase point is,the longer the length of the paste zone is,and the position is far away from the meniscus.With the increasing of casting speed,the length of liquid point and paste zone is longer,and the location of paste zone is far away from meniscus.The effect of different nucleation parameters and process on solidification structure was analyzed through the observation of solidification structure: Increasing the average undercooling can reduce the proportion of equiaxed grains and increase the grain size.When the maximum nucleation density is increased,the equiaxed grain fraction of the center increases and the grain size decreases.Reducing the second cold strength,so that the equiaxed crystal increases,the average size of the grain smaller.Increasing the casting temperature,so that the equiaxed crystal decreased,the average size of the grain size;increase the casting speed,resulting in more equiaxed crystal change,the average size of the grain decreases.While the increase of electromagnetic stirring can refine grains and increase the formation of equiaxed grains.