Journal of Casting & Materials Engineering
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ISSN 2543-9901
Issue Date
2022
Volume
Vol. 6
Number
No. 4
Description
Journal Volume
Journal of Casting & Materials Engineering
Vol. 6 (2022)
Projects
Pages
Articles
Optimization of ladle tilting speed for preventing temperature drops in the die casting process
(AGH University Press, 2022) Ando, Haru; Minamide, Daichi; Takagi, Yuto; Yano, Ken'ichi; Nakamura, Naoto; Sano, Masahiro; Aoki, Takahiro; Nemoto, Yasunori
In die casting, molten metal poured into a shot sleeve is pressed into a mold by a plunger at high speed. The temperature of the metal drops significantly while it is being poured from the ladle to the shot sleeve, resulting in casting defects such as misrun flow lines. Although it is important to control the temperature at all stages of the process, a method for minimizing temperature loss has not yet been clarified to date. In this study, the cause of the temperature drop in the shot sleeve was clarified, and a method of optimizing the ladle tilting speed was proposed to prevent temperature drop. First, experiments were conducted to measure the decrease in metal temperature in the sleeve during pouring. These experiments revealed that the metal cools significantly from the moment it touches the shot sleeve. Therefore, the time from the first contact between the shot sleeve and the metal to the start of pouring was set as the objective function. A genetic algorithm was then used to derive the optimal ladle tilting speed pattern to suppress the temperature drop. This analysis confirmed that the metal was poured without flowing out or running ahead and that the immediate liquid level vibration after pouring was suppressed, thus ensuring stable pouring.
The optimization of a numerical steel foundry simulation through a characterization of the thermal properties of the materials
(AGH University Press, 2022) Souêtre, Morgan; Vaucheret, Alexis; Jacquet, Philippe; Carton, Jean-François
In many foundries, numerical simulation is used to determine the origins of different defects as this tool allows the acceleration of the design process. However, the databases provided by different software do not seem to tally with the actual properties of the material. In fact, every foundry uses a different grade of steel and varying mixtures of sand. An evaluation of the impact of different material properties showed the importance of measuring every physical property to improve the database of the software. Following this, an experiment was conducted to evaluate the gap between numerical simulations and the results obtained through experimentation. This experiment, called thermal analysis, consists in measuring the solidification and cooling of a cylinder filled with liquid steel. After the calculation of the steel properties and a simulation with real experimental parameters, a comparison between each cooling curve was realized. This comparison shows that the calculated properties provide a simulated cooling curve which is closer to the experimental curve than the properties in the original database. We did not explore all of the metal properties in this study, but the modification of the sand properties was explored, together with the thermal conductivity of the steel and sand. These other measurements will be obtained in a future study.
The formation, properties and use of dispersed iron-graphite metallurgical waste
(AGH University Press, 2022) Dan, Leonid; Maslov, Vladimir; Trofimova, Larisa Alekseevna; Cios, Grzegorz
Dispersed wastes containing graphite, iron, and its oxides, getting into the air and accumulating in landfills, cause serious harm to human health and the environment. Moreover, even if the issue of the localization of these wastes has been solved successfully, their disposal has not yet been fully organized. In the present study, a systematic analysis of the dispersed iron-graphite waste (IGW) conditions for the formation at metallurgical enterprises, their structure, and their properties were carried out. In this case, special attention is focused on the electrophysical properties: specific saturation magnetization and volume resistivity. The presence of magnetic properties in IGW, combined with low electrical resistivity, makes IGW a promising and inexpensive raw material for obtaining cheap composite materials with radio shielding and radio absorbing properties in the microwave range. As a result of the research, effective ways of improving the magnetic properties of IGW by high-temperature treatment were obtained. The practical result of the research was the development and implementation of a technological scheme of dispersed IGW complex processing, which makes it possible to solve a twofold task - to exclude the ingress of iron-graphite wastes into the environment and to obtain a cheap material for protection against microwave radiation.