The background of the production of Calcium silicon aluminum barium: Deoxidation of molten steel is an essential process in the steelmaking process, and the choice of deoxidizer is very important. From the history of deoxidizers used in steelmaking, the pure aluminum (generally aluminum cake, A1 content > 95%) used at the beginning, due to its light specific gravity (2.79gPcm3), the aluminum cake is not easy to penetrate into the molten steel, thus limiting the absorption of aluminum elements. effective utilization. Compared with silicon-calcium-barium-aluminum, silicon-aluminum-iron composed of Si and A1 is used instead of aluminum cake, so the weight increases (about 4.3gPcm3), and the effective utilization rate of A1 element is doubled. Consumption is also reduced accordingly.
In recent years, with the transformation of steel from a seller to a buyer’s market, companies are forced to pay more attention to improving the intrinsic quality of steel. Composite deoxidizer is because of having strong deoxidation ability, can obviously improve the advantages such as molten steel purity, is subjected to the general concern of numerous research institutes and iron and steel enterprises naturally, becomes the hotspot of research and development in the recent deoxidizer field, wherein especially contains alkaline earth element Ba The research on the compound deoxidizer of Ca and Ca is the most active. The choice of deoxidizer, aluminum in silicon calcium barium aluminum is used as the traditional deoxidizer for steelmaking, due to the strong affinity between aluminum and oxygen and the characteristics of complete mutual solubility between aluminum and iron. It also determines that the status of aluminum as an essential part of the final deoxidizer in steelmaking will be difficult to change for a long time, but because aluminum is added to steel, it is easy to form high melting point deoxidation products, which will make the fluidity of molten steel worse, which will seriously affect the quality of molten steel. The pourability of aluminum alloys poses a threat to the smooth flow of continuous casting production, so the amount of aluminum added during steelmaking deoxidation is limited.
Studies have shown that the introduction of strong deoxidizing element Ca into aluminum-containing deoxidizers can effectively denature the high melting point inclusions produced by deoxidation, thereby significantly improving the fluidity of aluminum deoxidized molten steel. Low solubility, light specific gravity, high vapor pressure and other weaknesses, how to improve the effective utilization rate of silicon, calcium, barium and aluminum has become a problem that must be considered when determining the composition of the deoxidizer. Studies have shown that Ba element is not only a strong deoxidizer with a large specific gravity and low vapor pressure. And it is completely miscible with Ca, and the vapor pressure of Ca will be significantly reduced with the increase of its content. Therefore, the development and use of calcium-containing high-barium and low-aluminum composite deoxidizers has become a common problem for ferroalloy manufacturers and steel mills, representing the future. The development direction of deoxidizers for steelmaking.
Silicon-calcium-barium-aluminum is the best deoxidizer and desulfurizer in barium alloys, which can minimize the oxygen in the steel, and at the same time, the complex oxides containing calcium, barium, silicon and aluminum formed are easy to float from the molten steel. Pure liquid steel improves the impact resistance toughness and processability of steel. Silicon-calcium-barium-aluminum is a high-efficiency deoxidizer and an auxiliary material for steelmaking. It is suitable for deoxidation in various forms of steelmaking, especially for converter steelmaking deoxidation. It has a strong deoxidation and desulfurization effect, can improve the flow performance of molten steel, and solve the problem of nozzle nodulation. To reduce gas in steel and reduce inclusions in molten steel, it is of great significance to accurately determine calcium in silicon, calcium, barium, and aluminum.