Комп’ютерне моделювання формування 50-тонного листового злитка

• Дата: 2023
• Автори: Біктагіров, Ф.К., Шаповалов, В.О., Гнатушенко, О.В., Качан, Р.Ю.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: плоский злиток; моделювання; MagmaSoft; розливка; температура металу; затвердіння; двофазна зона; усадкові дефекти
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/158
• Назва журналу: Metal and Casting of Ukraine

This article is devoted to investigation of peculiarities of 50-ton sheet ingot formation from steel of the type 15Г2СФ, which is used to manufacture steel plates. With the use of the software package “MagmaSoft” computer simulation of casting and solidification of metal was performed. It is shown, that after completion of siphon casting, the metal in central axial zone of the ingot has a higher temperature than the overlying horizons. Central zone by height of the mold is also more heated to a temperature of 650–700 °C. According to the simulation results, the total solidification time of the metal upon making this ingot is about 8 hours. As the metal solidifies, the length of the two-phase zone increases and, starting from about 2 hours after the end of casting, the rate of the liquid-solid state volume growth increases sharply. By 3 o’clock from the beginning of the solidification period, the length of the two-phase zone along the ingot axis is about 35 % of the ingot body height, and by 4.5–5 hours it is already almost 80 %. Modeling shows that a narrowing of the metal bath at the top of the mold gradually occurs and by 3.5 hours after the end of the casting, the two-phase zone in the upper part of the ingot completely covers the underlying areas of the liquid state. Therefore, from this time on, it is difficult for liquid metal to flow deep down in the ingot, which leads to the formation of shrinkage voids and increased metal porosity at the distance of 300–500 mm from the ingot top. The revealed features of 50-ton sheet ingot formation indicate the presence of shrinkage origin defects in it, which can be detected with ultrasonic thick plates testing. Therefore, it is necessary to improve the initial cast billet quality, for example, using the electroslag heating and feed technology, that allows you to improve both physical and chemical homogeneity of such ingots.