Study On Solidification And Friction Of Molten Steel In Continuous Casting Slab Mould

With the development of modern continuous casting technology,how to improve the efficiency of continuous casting has become the primary task of contemporary metallurgical workers.However,there are still many defects in the continuous casting production,among which steel leakage is the most dangerous production accident in the continuous casting process,which will not only reduce the quality of the slab,but also endanger the personal safety.Based on the current theoretical research of heat transfer and friction in continuous casting mold,the influence of friction between slab and mold on pull out leakage is studied by numerical calculation and finite element simulation,mainly including the following aspects:Firstly,the finite element models of the heat transfer of molten steel solidification and the heat transfer of copper plate in the mold are established by using ANSYS software,and the distribution of the two temperature fields is simulated,and the temperature changes of the characteristic parts are obtained.By changing the drawing speed,the temperature variation of continuous casting slab and mould copper plate is studied,which provides temperature data for friction calculation.Secondly,N-S equation and Coulomb's law are used to calculate the friction distribution between slab and mould.The law that the increase of solid friction is faster than that of liquid friction is obtained.At the same time,change the casting temperature and compare the change of friction force under different casting temperature.Finally,the finite element model of the shell is established by using SolidWorks software and the thickness distribution of the shell,and the stress state of the shell is analyzed.In this paper,the contact algorithm of ANSYS software is used to assume that the mold copper plate is a rigid body to make it contact with the shell.The equivalent stress distribution in the shell is simulated and calculated under the conditions of thermal stress,friction force and static pressure of molten steel,and the relationship between the stress and the critical stress is analyzed,which provides a theoretical basis for judging the pull leakage.The main conclusions of this paper are as follows: the pulling speed has a great influence on the friction between the mold and the slab.In the case of sinusoidal vibration,when the pulling speed increases from 0.75m/min to 1.25m/min,the friction will increase accordingly.With the increase of the pulling speed,the surface stress of the shell exceeds the critical stress in turn near the meniscus and at the alternation of solid-liquid friction,and the probability of pulling leakage increases.At the same casting speed,the casting temperature increases from 1538 ? to 1552 ?,and the friction force decreases.The casting temperature has little effect on the friction force,but it is beneficial to increase the lubrication length.