Investigation of Continuous Casting Slag Films Sampled on Site and Comparison with Laboratory Results

2013 ◽  
Vol 13 (1-2) ◽  
pp. 103-114 ◽  
Author(s):  
Irmtraud Marschall ◽  
Nathalie Kölbl ◽  
Harald Harmuth ◽  
Guangmin Xia
Keyword(s):  
Continuous Casting ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Slag Film ◽  
Crystalline Layer ◽  
Al Content ◽  
Steel Grades ◽  
Casting Steel ◽  
The Impact ◽  
Ti Content

AbstractSlag film samples together with their associated mold fluxes were collected after service during tail out at the voestalpine Stahl GmbH continuous casting machine. The slag films were obtained after casting steel grades different in Al or Ti content and mineralogically investigated. Three distinctive layers could be determined within the slag films. A so called glassy layer, a crystalline layer and a layer, which has been liquid during casting and solidified afterwars, could be observed. Cuspidine (Ca4Si2O7F2) is the prevailing crystal phase in the crystalline layer. Casting alloyed steel grades the structure of the crystalline layer will be modified. With increasing Al2O3 content of the slag, due to interactions with the steel, nepheline ((Na,K)AlSiO4) was formed besides cuspidine. Here the distinctive needle like shaped cuspidine is remarkable. With casting steel grades with even more elevated Al content, the slag composition shows a strong decrease of silica and an increase of alumina. Therefore no longer cuspidine but fluorite (CaF2) and a so far unknown phase rich in alumina are the main crystal phases. When casting steel grades with increased Ti content, perovskite (CaTiO3) will be formed additionally to cuspidine in the crystalline layer.In addition quench tests of the original mold powders as well as DTA and viscosity measurements of the original mold powder and the slag films were performed. The methods revealed the impact of the Al2O3 and TiO2 pick-up on the crystallization temperature, the phase composition and the viscosity.

scholarly journals Study of the Influence of Intermix Conditions on Steel Cleanliness

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 852 ◽  
Author(s):  
Branislav Bul’ko ◽  
Marek Molnár ◽  
Peter Demeter ◽  
Dana Baricová ◽  
Alena Pribulová ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Negative Impact ◽  
Cast Steel ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Chemical Compositions ◽  
Negative Effect ◽  
Type Size ◽  
Steel Cleanliness ◽  
Steel Grades

Modern steel plants produce today a large portfolio of various steel grades, many for end-uses demanding high quality. In order to utilize the maximum productivity of the continuous-casting machine, it is sometimes necessary to cast steel grades with different chemical compositions in one sequence. It is important, therefore, to know the possibilities of a specific continuous-casting machine to make the Intermix connections as short as possible. Any interference with established procedures may, however, have a negative impact on the cleanliness of the cast steel. Using physical and numerical simulation tools, it was found that reducing the steel level in the tundish during the exchange of ladles makes it possible to shorten the transition zone. However, when the steel level is reduced, the flow of steel is impaired, which can have a negative effect on the cleanliness of the cast steel and, in extreme cases, may even lead to entrapment of slag in the mold. The cleanliness of cast steel was evaluated using one of the most advanced tools for automatic steel cleanliness evaluation, AZtecFeature (Oxford Instruments, Abingdon, UK), which enables determination of the type, size, distribution, and shape, as well as the chemical composition, of individual types of non-metal inclusions.

scholarly journals Influence of Cooling Conditions on a Slab’s Chill Zone Formation During Continuous Casting of Steel

2017 ◽  
Vol 62 (2) ◽  
pp. 911-918 ◽  
Author(s):  
P. Drożdż
Keyword(s):  
Continuous Casting ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Continuous Casting Of Steel ◽  
Secondary Cooling ◽  
Zone Formation ◽  
Casting And Solidification ◽  
Cooling Conditions ◽  
Chill Zone ◽  
The Impact

AbstractThe cooling conditions of a slab during continuous casting of steel have an impact on the crystalline structure formation. Numerical methods allow real processes to be modelled. Professional computer programs are available on the market, so the results of their simulations allow us to understand the processes that occur during the casting and solidification of the slab. The study attempts to evaluate the impact of the intensity of the secondary cooling on the chilled zone size. The calculations show the differences in the structure of a slab cast with various speeds while maintaining industrial cooling parameters during operation of a continuous casting machine.

scholarly journals Optimization of the Continuous Casting Process of Hypoeutectoid Steel Grades Using Multiple Linear Regression and Genetic Programming—An Industrial Study

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 972
Author(s):  
Miran Brezocnik ◽  
Uroš Župerl
Keyword(s):  
Tensile Strength ◽  
Continuous Casting ◽  
Continuous Caster ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Strength Tests ◽  
Steel Grades ◽  
Hypoeutectoid Steel

Štore Steel Ltd. is one of the major flat spring steel producers in Europe. Until 2016 the company used a three-strand continuous casting machine with 6 m radius, when it was replaced by a completely new two-strand continuous caster with 9 m radius. For the comparison of the tensile strength of 41 hypoeutectoid steel grades, we conducted 1847 tensile strength tests during the first period of testing using the old continuous caster, and 713 tensile strength tests during the second period of testing using the new continuous caster. It was found that for 11 steel grades the tensile strength of the rolled material was statistically significantly lower (t-test method) in the period of using the new continuous caster, whereas all other steel grades remained the same. To improve the new continuous casting process, we decided to study the process in more detail using the Multiple Linear Regression method and the Genetic Programming approach based on 713 items of empirical data obtained on the new continuous casting machine. Based on the obtained models of the new continuous casting process, we determined the most influential parameters on the tensile strength of a product. According to the model’s analysis, the secondary cooling at the new continuous caster was improved with the installation of a self-cleaning filter in 2019. After implementing this modification, we performed an additional 794 tensile tests during the third period of testing. It was found out that, after installation of the self-cleaning filter, in 6 steel grades out of 19, the tensile strength in rolled condition improved statistically significantly, whereas all the other steel grades remained the same.

scholarly journals Investigation of internal defects formation reasons in copper billet obtained at rotary continuous casting machine (CCM)

2020 ◽  
Vol 28 (1) ◽  
pp. 48-54
Author(s):  
A.N. Smirnov ◽  
◽  
V.E. Ukhin ◽  
A.P. Verzilov ◽  
Ali Naseri ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Internal Defects

Sensorless electric drive of the mixture supply system in the mold of the continuous steel casting installation

2021 ◽  
pp. 16-21
Author(s):  
K. V. Litsin ◽  
D. M. Utyamishev
Keyword(s):  
Continuous Casting ◽  
Electric Drive ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Steel Production ◽  
Angular Speed ◽  
Quality Level ◽  
Actual Direction ◽  
Vector Control System ◽  
The Cost

The system of automatic feeding of the slag-forming mixture into the mold of the continuous casting machine was investigated in this article. The necessity of using a slag-forming mixture in the process of steel production has been substantiated. The proofs are given that the consumption of the slag-forming mixture significantly affects the cost of the final product. The quality level of the final product depends on the uniformity and consistency of the mixture supply to the crystallizer. Therefore, the actual direction is the automation of the process of feeding the slag-forming mixture into the mold of the continuous casting machine. The description of the developed automatic installation, which implements the supply of slag-forming mixture, is presented. The necessity of using a sensorless electric drive for moving the trolley has been substantiated. A simulation model of a bogie electric drive with a vector control system based on sensorless determination of the angular speed of the engine has been developed. The description of the method for determining the angular speed of the motor based on the known values of phase voltages is given. The simulation of the developed electric drive system in the Matlab Simulink program, confirming the adequacy of the developed system. The introduction of a sensorless electric drive into the system for feeding the mixture into the mold of the continuous casting machine will increase the reliability of the entire system and reduce its weight and dimensions.

Microstructural Evolution of Electromagnetically Stirred Al Alloy during Isothermal Reheating in Solid-Liquid Region

2005 ◽  
Vol 486-487 ◽  
pp. 338-341
Author(s):  
Dock Young Lee ◽  
Ki Bae Kim ◽  
Do Hyang Kim
Keyword(s):  
Continuous Casting ◽  
Casting Speed ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Electromagnetic Stirring ◽  
Al Alloy ◽  
Liquid Region ◽  
Α Phase ◽  
Solid Liquid ◽  
Holding Temperature

The effects of reheating in solid-liquid region on the microstructure of electromagnetically stirred Al alloy have been investigated. The billet of Al alloy was produced at a various casting speed from 200 to 500 mm/min in a continuous casting machine with an electromagnetic stirring device. The microstructure of the billet, which was isothermally reheated in a solid-liquid region during holding for from 0.5 to 15 min, was examined. The roundness and size of primary α phase of electromagnetic stirred Al alloy was measured according to the reheating time. The roundness of primary α phase was obtained a minimum during holding for from 3 to 7 min at a holding temperature of 584°C and was deteriorated at a longer reheating time due to a dominant coalescence. Also the spheroidization of primary α phase during reheating in solid-liquid region was significantly dependent on initial microstructure of the billet.

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