Безперервне розливання нікелевих сплавів у прутки круглого перерізу для отримання з них гранул

• Дата: 2025
• Автори: Chistyakov, O. V., Nuradinov, A. S., Nogovitsyn, A. V., Seredenko, O. V., Sirenko, K. A., Nuradinov, I. A.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Physico- Technological Institute of Metals and Alloys of the NAS of Ukraine 2025
• Теми: нікелеві сплави; виплавка; безперервне розливання; гранули; якість; структура
• Онлайн доступ: https://momjournal.org.ua/index.php/mom/article/view/2025-1-7
• Назва журналу: Metal Science and Treatment of Metals

Nickel alloys are one of the key materials for applications in extreme operating conditions, where high corrosion resistance, strength at high temperatures, and stability in aggressive environments are required. In this work, a method of granulating experimental nickel alloys has been developed, in which one of the stages is their continuous casting. At the same time, technological modes of their continuous (vertical and horizontal) pouring into cast blanks (rods) of round section (8 mm) were worked out. Pellets 16 mm long were obtained from round continuous cast blanks by mechanical cutting, which at the final stages were subjected to tumbling (in three stages) and ultrasonic washing. The obtained granules were subjected to X-ray phase analysis and metallographic studies using standard methods. One of the main criteria for assessing the quality of nickel alloy granules is the amount of impurities in them, because they significantly reduce the corrosion resistance and durability of such materials. The work established that to ensure the minimum amount of impurities and uniformity of the chemical compositions of the granules from the studied nickel alloys, their melting must be carried out in a protective gas environment or in a vacuum. From the analysis of the microstructures of the samples, it was found that, regardless of the method of continuous casting of the studied nickel alloys, two zones (surface and central) were found in the granules, which differed in size, morphology of the grains of the base alloys and eutectic. It is obvious that the granules of both types were formed in conditions of unstable heat dissipation, since they are characterized by alternating areas with different microstructure within both surface and central zones. The "horizontal" granules are characterized by a thinner structure, in particular, the size of the longest dendrites was three times smaller than similar crystals formed in the "vertical" granules.