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.

Soft-Sensor for Estimation of Lead Slices Thickness in Continuous Casting Process

2011 ◽  
Vol 323 ◽  
pp. 40-45 ◽  
Author(s):  
Shi Lun Zuo ◽  
Jia Xu Wang ◽  
Tai Fu Li
Keyword(s):  
Continuous Casting ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Casting Process ◽  
Support Vector ◽  
Good Prediction ◽  
Soft Sensors ◽  
Continuous Casting Process ◽  
Study Results ◽  
Good Prediction Accuracy

Continuous casting process is a traditional and widely-used technique in producing the cathode of electric lead. In this paer, soft-sensors based on a support vector regression （SVR, in short）model and an artificial neural networks （ANNs, in short）model respectively, were presented for the estimation of the lead slices thickness in the process.Experiments had been performed on the continuous casting machine to obtain the data used for training and testing of the soft-sensors. For the continuous casting process, the soft-sensors proposed here represents a viable and inexpensive on-line sensors.The study results indicate that a good prediction accuracy of the slice thickess can be provided by the soft-sensors, and even a better performance can be achieved by using pre-processing procedures to the input data, it also shows that the SVR model is an attractive alternative to ANNs model for the soft-sensors, when the number of samples is relatively small.

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.

Numerical simulation of continuous casting process of different steel grades considering solidification and mixing of different steel grades

2015 ◽  
Vol 21 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Myunggeun Jeong ◽  
Changyoung Choi ◽  
Man Yeong Ha ◽  
Sung Jool Kim ◽  
Joong Kil Park ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Continuous Casting ◽  
Casting Process ◽  
Continuous Casting Process ◽  
Steel Grades

Microstructural Effects of Electromagnetic Stirring Strength and Casting Speed in Continuous Casting of Al Alloy

2004 ◽  
Vol 449-452 ◽  
pp. 321-324 ◽  
Author(s):  
Dock Young Lee ◽  
Ki Bae Kim ◽  
Ho In Lee ◽  
Do Hyang Kim
Keyword(s):  
Continuous Casting ◽  
Process Parameters ◽  
Casting Speed ◽  
Surface Defect ◽  
Continuous Caster ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Electromagnetic Stirring ◽  
Al Alloy ◽  
Primary Crystal

Semi-solid forming usually requires feed stock material in form of cylindrical billets with a uniform, globular and fine grain microstructure. These billets are commonly being produced by continuous casting involving agitation of the solidifying melt. The paper will present the development of a horizontal continuous casting machine using circumferential electromagnetic stirring to generate melt flow and shear rate in the continuous casting mould. The machine has been used to study the influence of various process parameters such as electromagnetic stirring strength and casting speed in the production of Al billet with a diameter of 76mm. In order to establish the quantitative relationship between microstructure and the process parameters, the morphology and primary crystal size of billet were observed according to the casting speed and electromagnetic stirring strength. A depth and distance of surface defect on the billet was decreased with increasing a casting speed and a very good smooth surface without any surface defect appeared on the billet produced at a casting speed of 600mm/min. A thickness of the solidifying shell was decreased with increasing the casting speed and the maximum casting speed without a break-out was 600mm/min in horizontal continuous caster designed in this study. Both the size and the aspect ratio of primary crystal were decreased with increasing the casting speed and electromagnetic stirring strength in the range of this study.

scholarly journals Method of Verification of Carbon Segregation Ratio Determined with Experimental Methods

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 499
Author(s):  
Jan Falkus ◽  
Katarzyna Miłkowska-Piszczek ◽  
Paweł Krajewski ◽  
Tomasz Ropka
Keyword(s):  
Continuous Casting ◽  
Continuous Caster ◽  
High Carbon Steel ◽  
Metal Flow ◽  
Casting Process ◽  
Segregation Ratio ◽  
Carbon Steels ◽  
High Carbon ◽  
Continuous Casting Process ◽  
Carbon Segregation

The problem of macrosegregation of alloying elements occurring during cast strand solidification in the continuous casting process is still valid; it is the subject of numerous experiments and theoretical considerations. A large percentage of this research is dedicated to carbon segregation, which, for understandable reasons, is vital for the production of high-carbon steels. The background knowledge on the mechanism of segregation occurrence indicates that it is a very complex effect, and a broad range of factors influencing the continuous casting process need to be considered. Therefore, it is difficult to translate information (provided by complex models of metal flow through a diphase area at the solidification interface of a cast strand) into practical engineering recommendations to reduce the macrosegregation effect. The presented study shows the latest research related to the carbon macrosegregation effect for selected high-carbon steel grades cast with a continuous caster. Problems related to the recording of the effect concerned have been pointed out. The second part of the paper presents the influence of selected casting parameters on carbon macrosegregation intensity when casting 160 × 160 billets with a six-strand caster. In this case, the main subject of the research was the influence of the casting speed on macrosegregation intensity. In the following step, an attempt was made to find the relationship between the cast strand structure and the distribution of carbon content on its cross-section. The ultimate objective of the presented study was to find an answer to the question on the technological capabilities of restricting the segregation effect.

scholarly journals A Comparison of Models Describing Heat Transfer in the Primary Cooling Zone of a Continuous Casting Machine

2015 ◽  
Vol 60 (1) ◽  
pp. 239-244 ◽  
Author(s):  
K. Miłkowska-Piszczek ◽  
M. Rywotycki ◽  
J. Falkus ◽  
K. Konopka
Keyword(s):  
Continuous Casting ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Casting Process ◽  
Research Problem ◽  
Cooling Zone ◽  
The Finite Element Method ◽  
Cast Slab ◽  
Thermal Boundary Conditions

Abstract This paper presents the findings of research conducted concerning the determination of thermal boundary conditions for the steel continuous casting process within the primary cooling zone. A cast slab - with dimensions of 1100 mm×220 mm - was analysed, and models described in references were compared with the authors’ model. The presented models were verified on the basis of an industrial database. The research problem was solved with the finite element method using the ProCAST software package.

Thermo-Mechanical Model of Steel Continuous Casting Process

2012 ◽  
Vol 57 (1) ◽  
pp. 355-361 ◽  
Author(s):  
K. Sołek ◽  
L. Trębacz
Keyword(s):  
Continuous Casting ◽  
Mechanical Model ◽  
Low Carbon Steel ◽  
Casting Process ◽  
Low Carbon ◽  
Continuous Casting Process ◽  
Casting Technology ◽  
Steel Continuous Casting ◽  
Simulation Of Casting Processes ◽  
Steel Grades

Thermo-Mechanical Model of Steel Continuous Casting Process In the paper a numerical model of heat and mass transfer in the mould zone in the steel continuous casting technology was presented. The model has been developed using ProCAST software designed for simulation of casting processes. It allows to determine temperature and stress distribution in continuous castings in order to optimize the most important process parameters. In this work calculations were executed for low carbon steel grades casted in the industry. In the simulations the real rheological properties measured in the experimental work and the boundary conditions determined on the basis of the industrial data were used.

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 Comparación y Efecto del Homogenizado en Billets de Aluminio AA 6063

2018 ◽  
Vol 3 (1) ◽  
pp. 322
Author(s):  
Bladimiro Hernán Navas Olmedo ◽  
Hernán Alberto Navas Moscoso
Keyword(s):  
Heat Treatment ◽  
Continuous Casting ◽  
Continuous Casting Machine ◽  
Casting Machine ◽  
Casting Process ◽  
Weight Percent ◽  
Alloying Elements ◽  
Negative Effect ◽  
The Difference ◽  
Aluminum Profiles

The lack of comparative studies about the distribution of the main alloying elements along aluminum billet´s AA 6063 widely use in extrusion companies to produce aluminum profiles, It makes necessary to counterpoise the difference between homogenized billet produced in horizontal continuous casting machine and a billet produced in vertical semi-continuous casting process. Applying spectrometric tests to quantify the weight percent of main alloying elements, brings out its own nature of each production process on every billet. Nevertheless, helped out by a metallographic test reveals in one billet the negative effect of an inadequate process of homogenization after the heat treatment process T5 in the aluminum profiles that holds it back to reach an adequate Webster hardness related to quality assurance. It reflects that is not enough to have a billet with a uniform chemical composition but the importance of an adequate billet´s heat treatment in order to be use in the extrusion process.Keywords: AA 6063, Billet, Comparison, Homogenized

The Air Reoxidation and the Formation of Large Inclusions in Continuous Casting Process

1973 ◽  
Vol 59 (1) ◽  
pp. 72-84 ◽  
Author(s):  
Kichinosuke MATSUNAGA ◽  
Chikakazu NAMIKI ◽  
Taiji ARAKI
Keyword(s):  
Continuous Casting ◽  
Casting Process ◽  
Continuous Casting Process
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