scholarly journals On longitudinal electromagnetic stirring in the continuous casting of steel blooms

2020 ◽  
Vol 120 (1) ◽  
pp. 129-151
Author(s):  
A. S. Nick ◽  
M. Vynnycky
2021 ◽  
pp. 17-22
Author(s):  
A. Yu. Tretyak ◽  
◽  
Qiang Wang ◽  
Chun-Lei Wu ◽  
E. I. Shifrin ◽  
...  

Today, the most promising and effective method of quality control of the continuously cast billets is electromagnetic stirring of the melt. In this case, an important component is the effect of the stirring on the jet in the nozzle. Moreover, as research has shown, this method is highly dependent on the configuration of the inner channel of the nozzle. Research have shown that positive or negative taper of the inner surface of the nozzle allows to obtain different results after applying EMS. Taper control completely changes the pattern of the melt flow and its deceleration in the mold, especially when it is casting of large billets. The results of the research show that minor changes in the taper of the nozzle significantly increase the effect of EMS implementation, which is observed already at 0.27 % of positive the taper and increases to 0.54%.


2021 ◽  
pp. 10-15
Author(s):  
A. Yu. Tretyak ◽  
Qiang Wang ◽  
Chun-Lei Wu ◽  
E. I. Shifrin

Continuous casting of steel has many ways to control the quality of the billets. The possibilities offered by electromagnetic stirring are far superior to physical eff ects, but combining these two quality control methods can be extremely effective. Research have shown the possibility of a qualitative effect on the flow of the liquid in the mold with implementation of electromagnetic stirring technology and the “skirt” is used in the form of a “shelf” on the nozzle, which is immersed in the mold. In addition, implementation of this shelf increase the possibilities of using direct-flow nozzles with the slope of the inner wall, where in each case it gives advantages, both with an expanding channel, and with a narrowing one. The design of the shelf also does not affect the implementation of electromagnetic stirring in the process of continuous casting, since it is below the level of the mold meniscus and above the level of the effect of the electromagnetic stirrer in the mold. The results of the research show that when using a “shelf” in the middle of the immersion nozzle depth, the casting process is accompanied by the control of most of the flows that are created when the jet enters into the mold and effect of EMS. It also affects the formation of vertex on the meniscus. And the implementation of a “shelf” at the outlet of the submersible nozzle completely changes the nature of the flow of the incoming jet.


Author(s):  
A.S. Nick ◽  
M. Vynnycky ◽  
P.G. Jönsson

A recent three-dimensional (3D) model that revisited earlier theoretical work for longitudinal electromagnetic stirring in the continuous casting of steel blooms is analyzed further to explore how the bloom width interacts with the pole pitch of the stirrer to affect the magnetic flux density. Whereas the first work indicated the presence of a boundary layer in the steel near the interface with the stirrer, with all three components of the magnetic flux density vector being coupled to each other, in the analysis presented here we find that the component along the direction of the travelling wave decouples from those in the other two directions and can even be determined analytically in the form of a series solution. Moreover, it is found that the remaining two components can be found via a two-dimensional computation, but that it is not possible in general to determine these components without taking into account the surrounding air. The validity of the asymptotically reduced model solution is confirmed by comparing it with the results of 3D numerical computations. Moreover, the asymptotic approach provides a way to compute the time-averaged Lorentz force components that requires two orders of magnitude less computational time than the fully 3D approach.


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