scholarly journals Development of a Two-Chamber MHD Tundish for Metal Ca

2021 ◽  
Vol 17 (4) ◽  
pp. 19-24
Author(s):  
Oleksii Smirnov ◽  
Anatoliy Narivskiy ◽  
Yevgen Smyrnov ◽  
Aleksei Verzilov ◽  
Anastasiia Semenko ◽  
...  

Introduction. The multifunctional magnetodynamic tundish prototype is the first world magnetodynamic mixer and batcher for steel, which has a capacity of up to 10 tons of melt and an inductor electric power of 600 kW. Ithas been successfully introduced into industry. Further works aim at adapting this device to continuous casting, in particular at obtaining semi-continuous cast billets at metallurgical micro-plants.Problem Statement. Today, the study of the effect of electromagnetic field on melt stirring and removal of non-metallics in the inlet chamber of MD-T is an urgent task.Purpose. The purpose of this research is to substantiate and to create MD-T as a two-chamber aggregate additionally equipped with a few electromagnetic & MHD devices for different purposes, to be used at metallurgical micro-mills.Materials and Methods. Physical modelling has been applied for studying liquid metal stirring under the action of electromagnetic field and the removal of non-metallics.Results. The behavior of the liquid jet falling from the ladle into the centrifugal chamber has been studied. The influence of the rational liquid level in the centrifugal chamber, which is exposed to the direct action of the electromagnetic field, has been estimated. It has been established that the effect of rotation of the total liquid volumehas been achieved at the height of application of electromagnetic field, which is 0.2—0.3 of the total fill height. Increasing the height of the application of a magnetic field leads to the capture of the upper layers of the liquid.Conclusions. There have been proposed a new design of magnetodynamic tundish (MD-T) for continuous casting of steel. The use of tundish with a rotational motion of the flow may significantly reduce the number of large oxide inclusions (larger than 10 µm) in steel. The device has been successfully tested and its application will improve the quality of cast billets, extend the functionality of equipment and technologies, and enable the realization of modern high-efficiency processes of continuous casting.

2014 ◽  
Vol 59 (2) ◽  
pp. 747-751 ◽  
Author(s):  
J. Szajnar ◽  
M. Stawarz ◽  
T. Wróbel ◽  
W. Sebzda

Abstract In paper problem concerning modification of grey cast iron EN-GJL-200 Grade, which is realized mainly by intensification of liquid metal movement in horizontal continuous casting mould containing electromagnetic stirrer is presented. The range of studies contains influence of electromagnetic field on morphology of graphite and usable properties i.e. tensile strength, hardness and machinability. Moreover the influence of velocity of ingot pulling on microstructure was analyzed. The results of studies and their analysis show possibility of improvement in quality of grey cast iron continuous ingot firstly in result of elimination of hard spots in structure by properly selection of velocity of ingot pulling and second in result of unification of size, shape and distribution of flake graphite by application of electromagnetic field.


2007 ◽  
Vol 26-28 ◽  
pp. 377-380
Author(s):  
Chun Hua Hui ◽  
Ting Ju Li ◽  
Wen Zhong Jin

In order to improve the quality of tin-phosphor bronze strips, the horizontal electromagnetic continuous casting technology, i.e. imposing alternating electromagnetic field to the horizontal continuous casting process of tin-phosphor bronze strips was developed. The effect of electromagnetic field on the quality of tin-phosphor bronze strips was studied with electron probe microanalysis (EPMA) and optical microscope. The results showed that when the alternating electromagnetic field with 50 Hz frequency and 18 A current was imposed, the crystal grain of the tin-phosphor bronze strips was obviously refined and the segregation and shrinkage cavity were greatly reduced. The quality of tin-phosphor bronze strips was remarkably improved, so the annealing time was shortened from 7 hours to 5 hours, and the service life of graphite mold was extended from 168 hours to 334 hours.


1988 ◽  
Vol 85 (3) ◽  
pp. 237-244 ◽  
Author(s):  
S. Kawasaki ◽  
Y. Suzuki ◽  
I. Takagi ◽  
H. Yasunaka

Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.


Alloy Digest ◽  
1989 ◽  
Vol 38 (4) ◽  

Abstract Ductile Iron grade 45-12 produced by continuous casting has consistent density and fine grain structure. It is the softest of the regular grades of ductile iron and it machines at high speeds with good surface finish. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties. It also includes information on heat treating, machining, and joining. Filing Code: CI-58. Producer or source: Federal Bronze Products Inc..


Author(s):  
Roberto Barcala-Furelos ◽  
Cristian Abelairas-Gómez ◽  
Alejandra Alonso-Calvete ◽  
Francisco Cano-Noguera ◽  
Aida Carballo-Fazanes ◽  
...  

Abstract Introduction: On-boat resuscitation can be applied by lifeguards in an inflatable rescue boat (IRB). Due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) and recommendations for the use of personal protective equipment (PPE), prehospital care procedures need to be re-evaluated. The objective of this study was to determine how the use of PPE influences the amount of preparation time needed before beginning actual resuscitation and the quality of cardiopulmonary resuscitation (CPR; QCPR) on an IRB. Methods: Three CPR tests were performed by 14 lifeguards, in teams of two, wearing different PPE: (1) Basic PPE (B-PPE): gloves, a mask, and protective glasses; (2) Full PPE (F-PPE): B-PPE + a waterproof apron; and (3) Basic PPE + plastic blanket (B+PPE). On-boat resuscitation using a bag-valve-mask (BVM) and high efficiency particulate air (HEPA) filter was performed sailing at 20km/hour. Results: Using B-PPE takes less time and is significantly faster than F-PPE (B-PPE 17 [SD = 2] seconds versus F-PPE 69 [SD = 17] seconds; P = .001), and the use of B+PPE is slightly higher (B-PPE 17 [SD = 2] seconds versus B+PPE 34 [SD = 6] seconds; P = .002). The QCPR remained similar in all three scenarios (P >.05), reaching values over 79%. Conclusion: The use of PPE during on-board resuscitation is feasible and does not interfere with quality when performed by trained lifeguards. The use of a plastic blanket could be a quick and easy alternative to offer extra protection to lifeguards during CPR on an IRB.


2013 ◽  
Vol 27 (2) ◽  
pp. 175-180 ◽  
Author(s):  
D. Łuczycka ◽  
A. Czubaszek ◽  
M. Fujarczuk ◽  
K. Pruski

Abstract Possibilities of using electric methods for determining admixtures of oat meal to wheat flour, type 650 are presented. In wheat flour, oat meal and mixtures containing 10, 20 and 30% of the oat meal, moisture, protein, starch and ash content, sedimentation value, yield and softening of wet gluten were determined. In samples containing 0, 5, 10, 15, 20, 25, 30 and 100% of oat meal, the dielectric loss factor and conductivity were determined using an impedance analyzer for electromagnetic field frequency ranging from 0.1-20 kHz. It was found that the dielectric loss factor varied for tested material. The best distinguishing between tested mixtures was obtained at the measuring electromagnetic field frequency of 20 kHz. The loss factor was significantly correlated with the yield of wet gluten and the sedimentation value, parameters indicating the amount and quality of gluten proteins in flour.


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