Metallographic approaches to the study of melt produced in EAF with adaptation of classical thermal-time treatment to modern electric smelting

Modern liquid steel production technology provides the maximum iron content (more than 99 %), and the minimum impurity content at the final stage of electric smelting, as well as during metal tapping into a ladle with deoxidation and desulfurization. Many years of production experience show that one of the most important reserves for reducing the structural and chemical heterogeneity of steel and improving the quality of steel products in the steel industry is to develop the smelting technology and obtain an equilibrium, maximally homogeneous melt before crystallization. Metal crystallization occurs from a nonequilibrium state, which increases the chemical and physical heterogeneity of solid metal, reduces its service characteristics and leads to significant deviations in its quality from heat to heat. There are different ways to bring the melt into equilibrium. The most accessible way to obtain an equilibrium melt is through high-temperature exposure. Experimental work in the conditions of JSC “Vyksa Metallurgical Plant” showed that melt preparation for crystallization by thermal-time treatment (TTT) affects the solidification process and improves the microstructure and properties of solid metal. It is suggested to carry out a high-temperature effect of TTT on the melt precisely at the stage of smelting in an electric arc furnace (EAF).

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