Numerical Simulation On Solidification Process In Continuous Casting Of Thick Rectangular Billet Thick

In recent years,with the rapid development of national economy and bridges, tunnels,military equipment other industries also have been developing rapidly,making the demand of large section size steel in machinery and construction has increased dramatically.At the same time the quality of steel and performance are also put forward strict requirements.As a result,the study to improve the quantity and quality of the thick steel has become the most important casting research.In the production process of thick and large slab continuous casting billet,slab crack are accounted for more than half of defects in continous casting billet.Therefore it is important to control the crack and explore crack mechanism. In order to analyze the causes of the casting blank cracks,author discusses the property and magnitude of stress in the process of casting blank solidification.This paper uses finite element analysis software ANSYS and establishes the700mm×1 500 mm heavy slab continuous casting solidification heat transfer model and the elastic-plastic stress model.The numerical simulation of the temperature field and the stress field distribution form the crystallizer meniscus to the two district cooling of the solidification process of mold.At the same time,we do analysis of continuous casting process parameters,such as casting speed,superheat and quantity of on the solidification process,for the influence of the temperature field and stress field distribution.In order to investigate the mechanism of crack,prevention and reduction of crack formation to provide a basis to improve the quality of slab. Concrete work as following:(1) Establish the thick rectangular billet continuous casting of two-dimensional mathematical model of solidification heat transfer.In this paper, based on the problems of modeling,Three new models of slab casting are put forward.They are the rectangular model,fillet model and chamfering model.By using two-dimensional slice method respective finite element simulation,the temperature distribution of the slab and solidified shell growth situation are obtained,and furthermore considering which is how to change under different technological conditions,then the most reasonable slab model is determined.(2) Establish the thick rectangular billet continuous casting of two-dimensional of the elastic-plastic stress model.On the basis of the slab temperature field,at the same time taking full consideration to the material of high temperature mechanics performance parameters.Indirect method is used to analyse the stress field of billet thermal coupling simulation study.And furthermore considering which is how to change under different technological conditions.It has once again proven the validity of the new slab model.(3) Combined with the simulation results of temperature field and stress field of the slab,calculating the crack exponent on the surface of casting blank and analyzing the technique measures for reducing crack.Finite element analysis software ANSYS numerical simulation used on the700mm×1 500 mm heavy slab continuous casting process of the temperature field and stress field,can be directly clear showed the various points in the process of casting solidification temperature distribution, the growth of shell, the shell shrinkage and stress distribution of solidified shell. The changes of temperature and the formation and development of thermal stress in the process of the continuous casting can be truly reflected.It can be used to prevent the formation of defects such as cracks in the process of production,and adjust the continuous casting process parameters for certain reference value.