Scientific Foundations for the Development of Innovative Technological Solutions for Producing Next-Generation Structural Steels with Enhanced Properties

The results of fundamental investigations of the physicochemical properties of the slags in the CaO–SiO2–FeO–MnO–P2O5–MgO and CaO–SiO2–B2O3–Al2O3–MgO systems are presented. They are the basis of a technology developed to melt semifinished steel products in oxygen converters and modern electric arc furnaces (EAFs) under magnesia-based slags. This technology provides a high-durability refractory lining in EAFs and a guaranteed low phosphorus content. Moreover, it includes innovative technological solutions for deep desulfurization and direct boron microalloying of structural steels in ladle furnaces (LFs) using environmentally friendly basic boron-containing slags. The introduction of these technological solutions has allowed for the production of next-generation low-carbon low-manganese-alloy boron-containing structural steels. These steels have a low sulfur content and enhanced mechanical properties, making them ideal for large-diameter strength class X80 pipes.