Influence of the presence of a “shelf” on the outer surface of the submerged nozzle and the electromagnetic effect within its length on the qualitative distribution of metal flows during continuous casting of steel

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.

2011 ◽  
Vol 295-297 ◽  
pp. 1284-1288 ◽  
Author(s):  
De Wei Li ◽  
Zhi Jian Su ◽  
Li Wei Sun ◽  
Katsukiyo Marukawa ◽  
Ji Cheng He

Swirling flow in an immersion nozzle is effective on improving quality of casting block and casting speed in continuous casting process of steel. However, a refractory swirl blade installed in the nozzle is liable to cause clogging, which limit the application of the process. In this study a new process is proposed, that is a rotating electromagnetic field is set up around an immersion nozzle to induce a swirling flow in it by Lorentz force. New types of swirling flow electromagnetic generator are proposed and the effects of the structure of the generator, the coil current intensity and frequency on the magnetic field and on the flow field in the immersion nozzle are numerically analyzed.


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%.


2011 ◽  
Vol 284-286 ◽  
pp. 1115-1119
Author(s):  
Cheng Gong Yao ◽  
Shou Qian Yuan ◽  
Lie Chen ◽  
Zhi Jun Wang ◽  
Hai Long Wang ◽  
...  

Q235D is one kind of peritectic steel, so the casting production inevitably encounter the universality defects of peritectic steel casting. The bloom(250mm×280mm) of Q235D is produced by 60t consteel EBT—LF(VD)—CC process at Xining Special Steel. The main problem in the production is the transverse corner crack, finally lead to occur the cracks and “triangular gaps” at surface of round bar(Φ130mm)after rolled. In order to eliminate the defects caused by transverse corner crack of bloom, the morphology and microstructure and principle of crack formation is researched. The results showed that the crack is caused by stress along the intergranular, and no obvious segregation and particles founded around the defects. The following parameters on the continuous casting process are optimized: steel composition, superheat, the choice of a various slag, the cooling water of different section, casting speed and the electromagnetic stirring parameters. Finally the cracking defects of the bloom is eliminated, and the quality of the bar is optimized.


2012 ◽  
Vol 602-604 ◽  
pp. 478-481
Author(s):  
Hong Pan

Cut-to-length bloom can not be controlled at the end of continuous casting process, and the yield of bloom is low. In order to improve the yield of bloom, the CC tail bloom system is proposed according to the bloom continuous casting conditions of equipment and process. Importantly, it is applied in the optimization of tail bloom operation in continuous casting process. Industrial tests show that the yield of bloom is improved obviously, with the quality of bloom is controlled as before.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6309
Author(s):  
Paweł Kwaśniewski ◽  
Paweł Strzępek ◽  
Grzegorz Kiesiewicz ◽  
Szymon Kordaszewski ◽  
Krystian Franczak ◽  
...  

Today’s world is a place where lack of electrical energy would be unimaginable for most of society. All the conductors in the world, both aluminum and copper, have their origin in various types of casting lines where the liquid metal after crystallization is being processed into the form of wires and microwires. However, the efficiency of the continuous casting processes of metals and the final quality of the manufactured product strictly depend on the design of the used crystallizers, the materials used during its production and its quality. Research conducted in this paper focuses on the latter, i.e., external surface quality of the graphite crystallizer at the place of contact with the primary cooling system. In order to quantify its influence on the continuous casting process numerical analyses using the finite element method has been conducted, which results have been further confirmed during empirical tests in laboratory conditions. It has been proven with all of the proposed methods that the temperature of the obtained cast rod is closely linked to the aforementioned surface quality, as when its roughness coefficient surpasses a certain value the temperature of the obtained product increases almost twofold from approx. 150–170 °C to 300–320 °C. These values might influence the quality and final properties of the cast rod, the susceptibility to wire drawing process and possible formation of wire drawing defects and therefore be of much importance to the casting and processing industry.


2015 ◽  
Vol 60 (4) ◽  
pp. 2927-2932
Author(s):  
J. Pieprzyca ◽  
T. Merder ◽  
M. Saternus

The way and speed of steel flux flowing into mould of continuous casting (CC) machine belong to the important parameters characterizing the steel continuous casting process. Such flux causes determined kinds of steel circulation, which together with simultaneous steel crystallization influence the creation of ingots primary structure and quality of its surface. The article presents the results of modelling research which aim was to determine the optimal location of submerged entry nozzle in square moulds (130 x 130 mm and 160 x 160 mm) of CC machine. Such a research was carried out for two different grades of steel (low-carbon steel and high-carbon steel), which feature different parameters of casting.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 380 ◽  
Author(s):  
Zhufeng Lei ◽  
Wenbin Su

Control of the roll gap of the caster segment is one of the key parameters for ensuring the quality of a slab in continuous casting. In order to improve the precision and timeliness of the roll gap value control, we proposed a rolling gap value prediction (RGVP) method based on the continuous casting process parameters. The process parameters collected from the continuous casting production site were first dimension-reduced using principal component analysis (PCA); 15 process parameters were chosen for reduction. Second, a support vector machine (SVM) model using particle swarm optimization (PSO) was proposed to optimize the parameters and perform roll gap prediction. The experimental results and practical application of the models has indicated that the method proposed in this paper provides a new approach for the prediction of roll gap value.


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