The world’s first three-graphite electrode direct current(DC)plasma heating system(2500 kW)was successfully put into production on the 50-t tundish of a two-strand slab caster.The single metallic torch plasma tundish...The world’s first three-graphite electrode direct current(DC)plasma heating system(2500 kW)was successfully put into production on the 50-t tundish of a two-strand slab caster.The single metallic torch plasma tundish heaters were reviewed.In addition,the induction heating system was also estimated.The three-graphite electrode DC plasma tundish heating(PTH)system does not require any electrode to be fitted to the tundish.Five electrodes can be used to realize uniform and fast heating of the six-strand tundish.Heating with high power can effectively eliminate the steep temperature drop of the molten steel in the tundish during ladle change-over.The system has turned out to be very reliable,simple,and maintenance-free.The heating rate is high within 0.5 to 2.0℃/min.Some heats with ultra-low superheat(2.6-11.0℃)were observed,and the molten steels were successfully cast by the powerful heating capacity and good control performance of the system in the practical production.It can be concluded that continuous casting with superheat of 5-10℃in the tundish was fully realistic with PTH.展开更多
The electromagnetic,flow,heat transfer and inclusions motion model of the channel-type induction heating(IH)tundish was established,and the effect of the channel diameter on the metallurgical behavior of the tundish w...The electromagnetic,flow,heat transfer and inclusions motion model of the channel-type induction heating(IH)tundish was established,and the effect of the channel diameter on the metallurgical behavior of the tundish was studied.The results show that the magnetic field in the channel of the IH tundish tends to concentrate on the surface layer and the side near the coil.As the channel diameter is increased from 100 to 180 mm,the maximum value of magnetic flux density in the channel decreases by 0.125 T,and the maximum value of electromagnetic force decreases by 11.83×10^(5) N m^(-3);however,the off-center distance of magnetic field increases by 9.4 mm,and the Joule heat in the channel decreases by 1004 kW,which leads to the reduction in temperature rising rate of the tundish from 1.41 to 0.59 K min^(-1).When the channel diameter is 100,140 and 180 mm,the maximum velocity at the channel exit before heating is 0.59,0.29 and 0.18 m s^(-1),and after heating for 1800 s,it is 1.52,1.12 and 0.92 m s^(-1),respectively.In addition,the total inclusions escape ratio after heating for 1800 s with a channel diameter of 140 mm can be reduced by 12.39% compared to that before heating,and the maximum difference of escape ratios for each strand is only 4.51% and 5.32% before heating and after heating for 1800 s,respectively.Compared with the channel diameters of 100 and 180 mm,the channel diameter of 140 mm is more favorable to improve the metallurgical effect of the IH tundish.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52074030).
文摘The world’s first three-graphite electrode direct current(DC)plasma heating system(2500 kW)was successfully put into production on the 50-t tundish of a two-strand slab caster.The single metallic torch plasma tundish heaters were reviewed.In addition,the induction heating system was also estimated.The three-graphite electrode DC plasma tundish heating(PTH)system does not require any electrode to be fitted to the tundish.Five electrodes can be used to realize uniform and fast heating of the six-strand tundish.Heating with high power can effectively eliminate the steep temperature drop of the molten steel in the tundish during ladle change-over.The system has turned out to be very reliable,simple,and maintenance-free.The heating rate is high within 0.5 to 2.0℃/min.Some heats with ultra-low superheat(2.6-11.0℃)were observed,and the molten steels were successfully cast by the powerful heating capacity and good control performance of the system in the practical production.It can be concluded that continuous casting with superheat of 5-10℃in the tundish was fully realistic with PTH.
基金funded by the National Natural Science Foundation of China(NSFC)(Grant Nos.51874033 and U1860111).
文摘The electromagnetic,flow,heat transfer and inclusions motion model of the channel-type induction heating(IH)tundish was established,and the effect of the channel diameter on the metallurgical behavior of the tundish was studied.The results show that the magnetic field in the channel of the IH tundish tends to concentrate on the surface layer and the side near the coil.As the channel diameter is increased from 100 to 180 mm,the maximum value of magnetic flux density in the channel decreases by 0.125 T,and the maximum value of electromagnetic force decreases by 11.83×10^(5) N m^(-3);however,the off-center distance of magnetic field increases by 9.4 mm,and the Joule heat in the channel decreases by 1004 kW,which leads to the reduction in temperature rising rate of the tundish from 1.41 to 0.59 K min^(-1).When the channel diameter is 100,140 and 180 mm,the maximum velocity at the channel exit before heating is 0.59,0.29 and 0.18 m s^(-1),and after heating for 1800 s,it is 1.52,1.12 and 0.92 m s^(-1),respectively.In addition,the total inclusions escape ratio after heating for 1800 s with a channel diameter of 140 mm can be reduced by 12.39% compared to that before heating,and the maximum difference of escape ratios for each strand is only 4.51% and 5.32% before heating and after heating for 1800 s,respectively.Compared with the channel diameters of 100 and 180 mm,the channel diameter of 140 mm is more favorable to improve the metallurgical effect of the IH tundish.
