scholarly journals A Model-Based Predictive Controller of the Level of Steel in the Mold with Disturbances Using a Repetitive Structure

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1458
Author(s):  
Rogério P. do A. Pereira ◽  
Gustavo M. de Almeida ◽  
José L. Felix Salles ◽  
Marco A. de S. L. Cuadros ◽  
Carlos T. Valadão ◽  
...  
Keyword(s):  
Steel Industry ◽  
Casting Process ◽  
Real Data ◽  
Nonlinear Mathematical Model ◽  
Continuous Casting Process ◽  
Periodic Disturbances ◽  
Steel Slab ◽  
Repetitive Structure ◽  
Predictive Controller

Keeping the level of steel in the mold of the continuous casting process constant is fundamental for the quality of the steel produced and, consequently, its commercial value. It is challenging, considering the several disturbances that cause undesired variations in the mold level. The aim of this paper is to apply a repetitive structure composed of two controllers, a generalized predictive controller (GPC) and a repetitive GPC (R-GPC) with constraints to mitigate the bulging and clogging/unclogging disturbances and the casting speed variation in the mold level of the process. The R-GPC controller has the same characteristics as the GPC, such as performance, robustness to disturbances, and insertion of constraints, and its advantage is the elimination of periodic disturbances. The repetitive structure will be implemented with a robustness filter and tuned by a genetic algorithm (GA). The controller tests are performed by simulations of a nonlinear mathematical model of the mold level, validated using real data from the steel industry. The proposed controller reduces the bulging disturbance amplitude by 98.5% and at 25% of the frequency of reversions in the valve. Consequently, the proposed controller allows an increase in the valve life span, a reduction in maintenance costs, and quality improvement in the steel slab.

Development of Electromagnetic Swirling Flow in Immersion Nozzle in Continuous Casting Process of Steel

2011 ◽  
Vol 295-297 ◽  
pp. 1284-1288 ◽  
Author(s):  
De Wei Li ◽  
Zhi Jian Su ◽  
Li Wei Sun ◽  
Katsukiyo Marukawa ◽  
Ji Cheng He
Keyword(s):  
Continuous Casting ◽  
Swirling Flow ◽  
Casting Process ◽  
Continuous Casting Process ◽  
New Process ◽  
Electromagnetic Generator ◽  
Set Up ◽  
The Magnetic Field ◽  
Immersion Nozzle

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.

Effect of Strain Rate on Nb(C,N) Precipitation in Micro Alloy Steel Slab

2012 ◽  
Vol 535-537 ◽  
pp. 633-638 ◽  
Author(s):  
Zheng Hai Zhu ◽  
Sheng Tao Qiu
Keyword(s):  
Continuous Casting ◽  
Strain Rate ◽  
Alloy Steel ◽  
Casting Speed ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Precipitation Model ◽  
Strain And Strain Rate ◽  
Steel Slab

It was analyzed by strain-induced precipitation model that Nb(C,N) precipitation in micro alloy steel slab was effected by strain rate during continuous casting process. The results are as follows: The changing of casting speed could effect the time for 5%precipitation of Nb(C,N), which was decreasing with increasing casting speed at certain temperature and strain rate. Slab strain and strain rate were too small in bending zone and leveling zone. The effect of slab strain rate on Nb(C,N) precipitation could be ignore when Nb(C,N) precipitation in continuous casting process was studied.

scholarly journals Study of the Effect of Carbon on the Contraction of Hypo-Peritectic Steels during Initial Solidification by Surface Roughness

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 982 ◽  
Author(s):  
Dazhi Pu ◽  
Guanghua Wen ◽  
Dachao Fu ◽  
Ping Tang ◽  
Junli Guo
Keyword(s):  
Surface Roughness ◽  
Cooling Rate ◽  
Solidification Process ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Peritectic Steel ◽  
Laser Confocal Microscope ◽  
Initial Solidification

In the continuous casting process, the shrinkage of the peritectic phase transition during the initial solidification process has an important influence on the surface quality of peritectic steel. The initial solidification process of 0.10C%, 0.14C%, and 0.16C% peritectic steels was observed in situ by a high temperature laser confocal microscope, and the contraction degree during initial solidification was characterized by surface roughness. The results showed that under the cooling rate of 20 °C/s, the surface roughness value Ra(δ/γ) of 0.10C% peritectic steel was 32 μm, the Ra(δ/γ) value of 0.14C% peritectic steel was 25 μm, and the Ra(δ/γ) value of 0.16C% peritectic steel was 17 μm. With increasing carbon content, the contraction degree of the δ→γ transformation decreased, and the value of the surface roughness Ra(δ/γ) declined. Therefore, surface roughness can characterize the contraction degree of the δ→γ transformation in the initial solidification process of peritectic steel under the condition of a large cooling rate.

Research of Transverse Corner Crack and Optimization of Concasting Process for Bloom of Peritectic Steel Q235D

2011 ◽  
Vol 284-286 ◽  
pp. 1115-1119
Author(s):  
Cheng Gong Yao ◽  
Shou Qian Yuan ◽  
Lie Chen ◽  
Zhi Jun Wang ◽  
Hai Long Wang ◽  
...  
Keyword(s):  
Crack Formation ◽  
Cooling Water ◽  
Casting Process ◽  
Electromagnetic Stirring ◽  
Continuous Casting Process ◽  
Steel Composition ◽  
Corner Crack ◽  
Peritectic Steel ◽  
Casting Production

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.

Optimization of CC Tail Bloom Operation

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

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.

scholarly journals External Surface Quality of the Graphite Crystallizer as a Factor Influencing the Temperature of the Continuous Casting Process of ETP Grade Copper

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6309
Author(s):  
Paweł Kwaśniewski ◽  
Paweł Strzępek ◽  
Grzegorz Kiesiewicz ◽  
Szymon Kordaszewski ◽  
Krystian Franczak ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Surface Quality ◽  
External Surface ◽  
Cooling System ◽  
Casting Process ◽  
Electrical Energy ◽  
Wire Drawing ◽  
Roughness Coefficient ◽  
Continuous Casting Process

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.

Cases Analysis of Nonconformity in Ultrasonic Flaw Detection for Steel Plates

2011 ◽  
Vol 295-297 ◽  
pp. 917-920
Author(s):  
Yi Qiang Sun ◽  
Li Xin Wu ◽  
Ping Zhang ◽  
Zhi Fen Wang
Keyword(s):  
Flaw Detection ◽  
Casting Process ◽  
Slag Inclusion ◽  
Optical Microscope ◽  
Steel Plates ◽  
Continuous Casting Process ◽  
Ultrasonic Flaw Detection ◽  
Ultrasonic Flaw ◽  
Scanning Electron

The Optical Microscope and Scanning Electron Microscope were used to analyze the causes of Nonconformity in ultrasonic flaw detection for three steel plates. The metallographic and energy spectrum analysis show that the main reasons were inclusions, porosity and cracks respectively, which were caused by the slag inclusion, center porosity and center segregation of the billets. Improving the quality of the steel water and optimizing continuous casting process could reduce the defects, and increase the percent qualified in ultrasonic flaw detection.

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