Reasearch On Double-roll Thin Strip Casting Extrusion Electromagnetic Side Sealing Technology

As an important high technology in the development of contemporary steel industry,the most prominent advantages of double-roll thin strip casting and rolling technology are short production cycle,low energy consumption and low cost development.The solution side seal technology directly determines the continuity of the casting and rolling process,and also seriously affects the edge quality of thin strip.At present,the main application and development of side sealing methods are solid side sealing technology and electromagnetic side sealing technology.Although the solid side seal technology is widely used in industrial production,its problems such as high impact on the quality of cast and rolled thin strip,high material consumption and lack of environmental protection are difficult to meet the requirements of modern industrial production.The electromagnetic side seal technology has become a hot research topic with its advantages of no contact with the melt,better casting and rolling continuity and longer service life.However,the existing electromagnetic side seal method still has the defects of heating the casting roll,making the melt temperature unevenly distributed along the axis of the roll and the inability to balance the fluctuating changes of the melt in the melt pool,resulting in constant changes in the edge width of the cast and rolled thin strip.It seriously affects the side sealing effect of electromagnetic side seal,which greatly limits the development of electromagnetic side seal technology and the scope of engineering applications.Therefore,it is of great theoretical significance and engineering application value to study the extrusion type electromagnetic side seal method of metal melt pool to solve the above defects.Based on the basic theory of magneto-hydrodynamics,the interaction between magnetic field and conducting fluid and the flow behavior of metal melt under the action of magnetic field are analyzed to derive the electromagnetic pressure equation for two-roll thin strip casting and rolling extrusion type electromagnetic side seal,to give the guidelines for the use of electromagnetic pressure equation in practical applications,and to calculate the required magnetic induction strength and magnetic dynamic potential of the side seal melt along the depth direction of the melt pool.A two-dimensional numerical simulation model of the extruded electromagnetic side seal is established to analyze the effects of different electromagnetic parameters on the magnetic induction intensity and electromagnetic pressure in the melt pool,and to determine the material selection of the side seal device.The structure design of multiple pairs of magnetic poles and coil winding is proposed,a three-dimensional numerical simulation model of the side seal device is established,and the variation of magnetic induction intensity and electromagnetic pressure in the melt pool along the depth direction of the designed extruded electromagnetic side seal structure is analyzed to improve the structure of the side seal device and further improve the overall design of multiple pairs of magnetic poles and coil winding.Conduct static physical simulation experiments on extruded electromagnetic side seals,and simplify the side seal device model according to the application scenarios of extruded electromagnetic side seals and existing equipment and instruments.An experimental platform based on the extruded electromagnetic side seal device is built.Measure the magnetic field distribution and temperature change inside the melt pool under different working conditions by changing the values of electromagnetic parameters.Record the shape changes of the free surface of the side seal of the melt pool under different electromagnetic parameters.To verify whether the designed extrusion type electromagnetic side seal device can achieve the reduction of heating to the rolls and the effective control of the edge width of the thin strip.The paper addresses the technical defects of the existing electromagnetic side seal technology and proposes corresponding technical theories and improvement methods,which can largely reduce the heating of the cast rolls by the applied magnetic field and more effectively balance the fluctuation changes in the melt pool and control the edge width of the cast strip,providing the key technology and scientific basis for the melt pool extrusion type electromagnetic side seal.