Solidification End Position Determination Of Continuous Casting Slabs Based On Force Feedback Model

The internal quality problems of continuous slabs such as center segregation and center porosity seriously hinder the development of slab continuous casting technology towards the direction of high efficiency,continuity and automation.The results show that in the area near the end point of solidified liquid core of the billet,using the fan-shaped section down roller to conduct the soft reduction technology of solidified end of the billet can effectively improve the quality defects existing in the billet.The position of the soft reduction technology is not accurate,which will worsen the quality of the billet or improve the internal defects of the billet.The existing methods to predict the solidified end position of the billet include the pin-shooting method and the thermal tracking calculation method,both of which are subject to the actual working conditions of the production site and other factors,and the result of determining the solidified end position of the billet is not accurate enough.The establishment of a more accurate determination model of solidification end position of billet is of great significance to the development of continuous casting technology and soft reduction technology.A two-dimensional mathematical model of unsteady heat transfer of slabs was established to study the heat transfer of slabs during cooling and solidification.A two-dimensional finite element model of slab heat transfer was established to simulate the solidification heat transfer process of the slab in the crystallizer and secondary cooling zone.The influence of different drawing speed and superheat on the cooling and solidification heat transfer process was analyzed.The mechanical model of shell bulging deformation was established and the mechanical properties of shell bulging deformation during continuous casting were obtained.A mathematical model for determining the solidification end position of the billet was established based on the force feedback of the support roller in the sector section.According to the changing law of the reaction force of the support roller in the sector section when the solidification end position of the billet changed,the force feedback model for determining the solidification end position of the billet was obtained.The finite element simulation model of shell bulging deformation was established to simulate the bulging deformation of shell with different thickness,and the variation rule of shell bulging deformation with shell thickness increasing or decreasing was obtained.Built up the finite element simulation of casting solidification end force feedback analysis model,the different core status of slab process under the pressure of force feedback analysis,get down slab cross section in the process of stress change rule of feature points,as well as the supporting roller force feedback results,the corresponding relationship between slab solidification end location of the fan-shaped section of support roll force feedback is used to determine method of slab solidification end location.