Introduction
Rh top-blowing oxygen (RHB) technology is a process technology in which oxygen or oxygen-rich gas is blown onto the surface of the molten steel to reduce the concentration of carbon, hydrogen, nitrogen and other harmful elements in molten steel. It is a new type of process technology compared to traditional top-blowing decarbonization, and is mainly used for efficient refinement of various kinds of steels. RHB technology has been applied and studied in steelmaking all over the world, and the results of industrial applications have been very good. RHB has the advantages of high efficiency, energy saving, low pollution and good stability, which can improve the quality of steel products and reduce the emission of harmful substances in steel production.
RHB for carbon decrease
RHB technology is mainly used for decarbonization and purification of molten steel. Oxygen or oxygen-rich gas is injected into the molten steel surface to react with carbon and form carbon oxides, which is advantageous to remove the high carbon content in molten steel. According to the reaction rate, the RHB process is classified into two reaction types, active oxidation and controlled oxidation.
Active oxidation uses high-oxygen nuclear steel oxygen or oxygen-rich gas, and combines with the exothermic reaction to quickly deoxidize and reduce the carbon content in the molten steel. The high-pressure injection technology can quickly transport the high-density oxygen or oxygen-rich gas into the molten steel, accelerate the reaction rate, and obtain the purpose of decent carbon content.
Controlled oxidation is usually used for low carbon steel. Low oxygen nuclear steel oxygen is used, and a controlled injection technique is used at the same time, so that the oxygen can promote metallurgical reaction of the molten steel, reduce the carbon content and obtain the required carbon in the steel. The oxidation reaction must be carried out in a certain temperature range, and if it is too low, coking and decarburization may be caused; If the temperature is too high, the safety of the steelmaking process cannot be guaranteed.
RHB technology has the advantages of simple process, low energy consumption and low pollution, and can rapidly reduce the carbon content in molten steel below the required standard. After smelting, the molten steel is free of dregs and slag, and the steel liquid temperature is low, which is advantageous to reduce the energy consumption of subsequent processes.
RHB for other elements
The application of RHB process is not limited to carbon decrease. RHB process can also be used to reduce silicon, manganese, phosphorus, sulfur and other harmful and non-metallic inclusions in molten steel.
It is known that silicon reduces the strength, ductility and plasticity of steel, and reduces the quality of forging and casting parts. The RHB injection process can effectively reduce the silicon content in molten steel. Through the reaction between oxygen and silicon in molten steel, silicon will be oxidized and reacted with calcium boride or magnesium aluminum boride to form inclusion and enter the slag to be discharged from the furnace.
Manganese is an important element affecting the performance of steel, but excessive manganese will reduce the plasticity and impact toughness of steel. The RHB process can quickly adjust the manganese content in molten steel, and promote the oxidation reaction of manganese and other elements through the interaction between oxygen and the molten steel surface, ensuring the good quality of the molten steel.
Phosphorus and sulfur are commonly referred to as two pollutants in steel. The concentration of phosphorus and sulfur in molten steel must be controlled to make the steel meet the requirements of quality products. The RHB technology is effective in reducing the concentration of phosphorus and sulfur in molten steel by oxidizing them and discharging them in the form of slag or smoke.
In addition to carbon, silicon, manganese, phosphorus and sulfur, RHB technology can also be used to improve other elements such as vanadium, chromium and niobium in molten steel. It is believed that with the development of technology, RHB technology will be more widely used in steel refining, and exert its advantages to the fullest.
Conclusion
In the steelmaking industry, RHB technology with its advantages of high efficiency, energy saving, low pollution and good stability is widely used. Compared with traditional top blowing decarbonization, RHB technology not only can reduce the carbon content in molten steel, but also has strong adaptability in reducing the content of harmful elements such as silicon, manganese, phosphorus and sulfur. In addition, RHB can help improve the quality of molten steel by improving the content of various beneficial elements. At present, RHB technology has been widely used in steelmaking industries, and its development prospects are bright.
