Heat Load Analysis And Roller Profile Design Of Work Roller Of Heavy Reduction Rolling Process

In recent years,with the broadening and thickening of continuous casting billet section,its internal cooling conditions have been significantly deteriorated,resulting in shrinkage of the core shrinkage,porosity and segregation defects become more serious.In the case of insufficient compression ratio,the defects of the continuous casting core can not be effectively eliminated in the subsequent rolling process,which will affect the final product performance and even cause serious accidents.The continuous casting of high temperature and pressure rolling is the use of continuous casting machine exit slab surface temperature is low,the temperature of the heart of the special characteristics of temperature distribution,high pressure rolling high permeability to eliminate shrinkage within the slab,Loose and other defects.High temperature and high pressure rolling mill and continuous casting machine to form a continuous casting and rolling relationship,the speed of the mill and the continuous casting machine needs to match the speed of steel,so the rolling speed is low,no intermittent time,rolling and rolling contact long,and then In addition,the high temperature of the continuous casting slab causes the heat load of the roll to become larger and the hot cracking problem of the roll surface tends to occur.In addition,the main purpose of the slab rolling under high temperature and high pressure is to eliminate the shrinkage cavity and porosity And other defects,and roll roll form of the rolling process of deformation of the core infiltration and shrinkage,loose lamination has a certain impact.Therefore,this paper focuses on the hot cracking of roll work rolls and the design of roll shape in continuous casting slab under high temperature and high pressure.The main research contents,and the results are as follows:(1)The large-scale commercial finite element software was used to simulate and analyze the temperature field of continuous casting process of GCr15 steel in a continuous casting workshop of a factory,and the finite element model was revised and verified according to the measured surface temperature on the site;The temperature field of the continuous casting slab is taken as the initial temperature field.The temperature field of the work roll in the rolling process of the continuous casting slab under high temperature and high pressure is studied by the method of finite element numerical analysis,and compared with the temperature field of the work roll in the conventional rolling process The comparative analysis shows that under the same conditions of roll cooling,the heat load of the roll under the high temperature and high pressure rolling process is obviously higher than that of the conventional rolling process.(2)In order to solve the problem of thermal cracking on the roll surface,finite element method and stress field in continuous casting process,it provides a theoretical basis for the development and design of roll cooling system for high temperature and high pressure rolling process.(3)In order to avoid the hot and cold surface of the roll during the high temperature and high pressure rolling,a new type of roll with heat conduction strip inside is designed and developed.The influence of the arrangement form of the heat conduction strip on the roll temperature field is analyzed by finite element method.(4)Based on the experimental data of thermal simulation,the constitutive equation of high temperature viscoplasticity of GCr15 steel was established.On the basis of this,the finite element numerical simulation method was used to study the relationship between the three types of roll shape of flat roll,parabolic roll and flange roll The influence law of deformation and permeability of slab core during the process of high temperature and high pressure rolling of slab has laid a theoretical foundation for the choice of work roll type and optimal design of roll type curve in continuous casting slab under high temperature and high pressure.