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

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.

2005 ◽  
Vol 486-487 ◽  
pp. 338-341
Author(s):  
Dock Young Lee ◽  
Ki Bae Kim ◽  
Do Hyang Kim

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.


2012 ◽  
Vol 246-247 ◽  
pp. 341-345
Author(s):  
Shi Lun Zuo

In order to improve design efficiency and reduce design cost, a new method combining numerical simulation with experimental verification was proposed in this study. Firstly, controllable process parameters such as continuous casting speed and cooling water flow rate, are robustly designed according to the numerical simulation results of flow field, process experiments were subsequently done on a newly developed continuous casting machine of lead slice, then the robust optimal design for the continuous casting process were gained. The results show that the cooling water flow significantly affects axial thickness of the lead slice, while the casting speed determines mainly its circumferential thickness. When the casting speed is between 280L/min and 320L/min, and the cooling water flow rate is between 950r/min and 1100r/min at the same time, the axial thickness and circumferential thickness can been kept respectively in1.0±0.03mm and 1.0±0.1mm, which meet the robust design requirements.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 972
Author(s):  
Miran Brezocnik ◽  
Uroš Župerl

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.


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

2021 ◽  
pp. 16-21
Author(s):  
K. V. Litsin ◽  
D. M. Utyamishev

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.


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