Дослідження сучасних уявлень про природу формування відкладень в вогнетривах при розливаннi сталі. Повідомлення 2

• Дата: 2023
• Автори: Писарський, С.М., Смірнов, О.М.
• Формат: Стаття
• Мова: Українська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: розливання сталі; формування відкладень; включення; дендрити; пластинчасті включення; інгібування; кластеризація; адсорбцiонно-сольватний фактор; анізометрія; кристалізаційне зростання; переконденсація
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/149
• Назва журналу: Metal and Casting of Ukraine

Report 2 (Report 1, “Metall i lit’e Ukrainy”, № 1–2, 2019) continued analytical studies on important and poorly studied aspects of the deposit formation in refractories for casting systems. Since the deposits consist mainly of coral-like clusters, dendritic and lamellar structures close to them, and taking into account the diversity and in some cases the inconsistency of ideas on the mechanisms of their formation, the article analyzed the factors and regularities of these morphological types formation. It has been shown that the phenomenon of inhibition of individual crystal faces by surface-active impurities in iron plays an important role in the formation of the plate type crystalline structures. Taking into account the results of industrial studies and numerical modeling of the nucleation and growth of Al2O3 inclusions during the steel deoxidation, in Report 2 the conclusion is substantiated that dendritic and lamellar structures in deposits cannot be the result of deposition neither of the deoxidation product nor products of secondary oxidation of steel. They can be formed directly on the interfacial surface “refractory (deposits) – melt” in refractories for casting systems by the mechanism of crystallization growth. With regard to coral-like clusters, taking into account the available criticisms of the well-known “cavitation” clustering mechanism of crystalline Al2O3-containing inclusions in steel, qualitatively new approaches are proposed for developing a new clustering model. Within its framework, a number of characteristic features of the formation and spatial structure of such clusters are given satisfactory explanations (contact of inclusions of anisometric shape mainly along vertices, edges, lateral edges of polyhedrons and lamellar inclusions; low tendency to coagulation of spherical inclusions; high strength of clusters preventing their destruction in turbulent flows etc.). It is shown that the clustering process is an integral part of the formation of deposits. The results of the studies have permit to clarify the contours of the proposed for the development of a new physicochemical model of the phenomenon of the deposit formation in refractories during steel casting.