RH refining technology appeared, and its RH refining furnace also appeared.
RH is a vacuum cycle degassing device, which is used to dehydrogenate molten steel. In 1952, my country first applied vacuum smelting technology in steelmaking. Research on silicon steel containing about 2% silicon showed that "slag" phenomenon is easy to occur during continuous casting production, resulting in scrapping of molten steel, and even in severe cases, it is impossible to cast. Through many tests, it was proved that this is due to the presence of hydrogen and nitrogen in molten steel. In recent years, various vacuum purification technologies have gradually matured. With the development of vacuum melting technology, VD and RH melting technology will become the mainstream of smelting technology in the next few years.
The process flow of the RH refining furnace is: immerse the immersion tube into the molten steel to be treated, and then treat the molten steel. In the vacuum tank, due to the negative pressure of the vacuum tank, the molten steel is forced to flow into the vacuum tank in the suction tube. The two immersion tubes are the riser and the downcomer. Since argon is continuously injected into the molten steel through the riser, a large static pressure difference is formed with the descending pipe without argon blowing. The molten steel will enter from the riser, pass through the bottom of the vacuum tank, and then flow into the downpipe, forming a cycle that repeats itself. The extracted gas is cooled by the hot bend inlet air cooler and then sent out of the workshop by the vacuum pump. Under vacuum conditions, when the molten steel passes through the vacuum tank, gases such as argon, hydrogen and carbon monoxide are discharged in multiple cycles of the molten steel. On this basis, a series of smelting reactions such as carbon oxidation are carried out on the molten steel; such repeated cycles can purify the molten steel.
The traditional smelting process is divided into two stages: primary smelting and refining. Primary smelting - melting of furnace charge, dephosphorization, decarburization and alloying. On this basis, through deep decarburization, degassing, deoxidation, inclusion removal, composition control, molten steel temperature control and other means, the process and product structure are optimized, high value-added products are developed, and energy saving, cost reduction and efficiency improvement are achieved.
The RH refining furnace system is a secondary refining device used for the production of high-quality molten steel. The melting of molten steel is carried out in a vacuum tank equipped with refractory bricks. The lower part of the vacuum tank consists of two immersion pipes filled with refractory materials.
