Study On Wetting Behavior Of Molten Steel And Foam Ceramic Under Electric Field

At present,there are many kinds of inclusion removal technologies in the metallurgical process.Such as gas agitation,slag washing,vacuum treatment,flow control and electromagnetic purification,etc.However,the fine inclusions are still not well removed.In recent years,foam ceramic filter inclusion technology has been widely used in non-ferrous metals and small castings.However,there are still many problems in filtering large castings,such as foam ceramics are not strong enough,the filtration efficiency is low,long filtration time leads to severe temperature drop,causing blockage of the filter channels and affecting the quality of the casting.Increasing the pore size of the ceramic foam can avoid the above phenomenon,but the filtration efficiency has greatly reduced.Therefore,how to improve the filtration efficiency of macroporous foam ceramics is particularly important.In this paper,the filtration efficiency of large-aperture foam ceramics is improved from the viewpoint of improving the wettability between foam ceramics and molten steel by using an applied electric field.The influence of applied electric field on the wetting behavior between low temperature alloy and ZrO2,SiC and other refractory materials is discussed.The principle is analyzed theoretically.The influence of applied electric field on the wetting behavior between molten steel and ceramic materials such as ZrO2 and SiC was studied.The theoretical analysis was carried out from the aspects of interfacial tension,interface electric double layer and interface reaction.Finally,in the actual filtration experiment,the influence of applied electric field on the filtration of inclusions in molten steel using macroporous foam ceramic has been investigated.The conclusions are as follows:(1)The applied electric field has a great influence on the contact angle between ZrO2,SiC,Al2O3,MgO,graphite and other materials and low temperature alloys.Within a certain range,as the voltage or current increases,the wetting angle gradually decreases.(2)The applied electric field has a great influence on the contact angle between ZrO2,SiC,Al2O3,MgO,graphite,nozzle and other materials,and within a certain range,the wetting angle is gradually reduced with the increase of voltage or current.(3)The applied pulsed electric field has a great influence on the contact angle between the conductive material such as the nozzle and the molten steel,and within a certain range,the wetting angle is significantly reduced as the pulse current increases,and the pulse current can be compared with the direct current.The wet angle changes more rapidly,but the final result is consistent with the DC current.(4)The applied electric field can significantly improve the adsorption capacity of the macroporous foam ceramics on the inclusions in the steel,thereby more effectively filtering the inclusions in the steel and improving the filtration efficiency.Therefore,it is sufficient to apply an applied electric field to the large-aperture foam ceramic for filtering inclusions in the steel.