Effect of Wolastonite Mineral (CaO SiO_2) Content in Continuous Casting Powder to SEN Erosion

摘要

The basic idea of the work was to analyze the effect of the wollastonite mineral CaO SiO_2 content in the continuous casting powder related to the SEN erosion. In order to realize the research, experiments were conducted in the laboratory conditions. The research, experiment, was realized in the Magnohrom Kraljevo laboratory, and cryptonym furnace EV16 was used for refractory material behavior. Cut SEN pieces from the slag zone in the reduction atmosphere were treated in the furnace with three types of casting powder of different mixtures ratio of SRD1 (without wollastonite) and SRD2 (with wollastonite): Casting powder 1 -^sSRD1/SRD2 = 50/50 %, Casting powder 2 -^sSRD1/SRD2 = 25/75 % and Casting powder 3 -^sSRD1/SRD2 = 75/25 %. Temperature of the experiment was in the range of 1520°C - 1540°C, and treatment time was changed simulating the average casting time of the heat; one heat (45 min), two heats (90 min), and three heats (135 min). The experiment pointed out that the erosion of the SEN was reduced with the increased ratio of wollastonite in the casting powder. The erosion rate of the SEN exposed to the casting powder 2 in the laboratory conditions was 0.0055 mm/min, whilst the erosion rate of the SEN exposed to the casting powder 3 (with the least wollastonite content) was 0.0075 mm/min. Erosion rate of SEN exposed to the casting powder 2 was lower for the 26.27 % related to the casting powder 3, and 17.90% lower than the erosion rate of the casting powder 1 (the erosion rate of the casting powder 1 was 0.0067 mm/min). These laboratory experiments are very consistent with results obtained in the plant conditions [1,2,3], At that time, results indicated that SRD1 casting powder without wollastonite has the erosion rate 46 % higher than SRD2 casting powder with wollastonite. On the basis of the laboratory researches and earlier plant conditions researches it could be concluded that wollastonite mineral content in the casting powders has significant effect on the SEN erosion, in the way that the SEN erosion rate was decreased with the increased wollastonite content in the casting powders.