Scientific and technological bases of ladle processing by resonant-pulsating refining

Abstract

Currently, the technology of resonant-pulsating metal refining (RPR) becomes more widely used for refining cast iron and steel. The paper highlights the stages of development of resonant-pulsating refining to improve the quality of products and presents the results of physical and mathematical modeling of metal refining with nitrogen and argon. It is established that physical modeling gives a good qualitative picture of the processes of metal blowing in the ladle by tuyeres of various designs. Mathematical modeling allows us to quantify the optimal parameters of blowing with argon and nitrogen in ladles of different capacities, depending on the ladle size and on diameters of tuyere and pulsator. The influence of this type of metal blowing on gas content, microstructure of cast iron, its mechanical and performance properties of products made of it was evaluated. It was found that the strength properties of cast iron increased from 91 - 105 to 130 - 170 MPa, the hardness increased from 137 - 150 to 163 - 182 HB, and the density also increased from 6890 - 6900 to 7000 - 7200 Kg/m 3 . In addition, it should be noted that the use of the presented technology can significantly reduce the harmful effects of phosphorus. The operational stability of products made of blast-furnace cast iron has reached the best domestic and foreign indicators. This technology has also proved to be effective in continuous casting of steel on high-grade casters. It made it possible to achieve the best performance in the industry with minimal costs during implementation. The developed technology is easy to implement on existing steel non-furnace processing units and on continuous steel casting machines. It can be widely used in foundries, electric steelmaking and oxygen-converter shops.