: processing capacity; circulating factor; the degassed time; circulation flow; degree of vacuum and suction capacity of vacuum pump in the vacuum of the work. Processing capacity, costumes, steel ladle of water, a small steel water temperature will reduce the excessive reach processing purposes. Ladle the general capacity of ≥ 30t. When the molten steel capacity, thermal stability, could easily be processed to achieve good treatment results World Steel Pipe News . The pressure of the vacuum chamber of the vacuum circulation degassing equipment is about 50 ~ 100Pa need 3min, totaling 10min to complete degassing of molten steel after three cycles, each cycle, coupled with 5min alloying and other operating requiring a total of 20min. Vacuum circulation degassing has to deal with fast-paced features, to be compatible with the rhythm of converter smelting. Can slow down the rhythm of the vacuum circulation degassing equipment used in the electric arc furnace shop. The circulation flow rate of the vacuum cycle by rising steel water pipe (t / min) per unit time. Factors affecting the circulation flow rate in the riser or downcomer diameter; improve gas flow; to enhance the steel surface of the distance of the gas from the vacuum chamber. Increase the value of these parameters can improve the circulation flow of the molten steel. But after a large increase in density is too small to make molten steel and the gas mixture, gas blocking the passage of the molten steel to reduce the circulation flow. The vacuum pump must have sufficient capacity to ensure that the vacuum level in the degassing treatment to ensure the quality of molten steel handling. Circulating factor, also known as cycles, refers to the steel water and ladle steel water than through the vacuum chamber in the process. General circulation factor of 3, after three cycles to complete the degassing process World Steel Pipe News . The
treatment effect after 30 years of development, the vacuum cycle approach can accomplish the following functions: (1) molten steel degassing, deoxidation. In the molten steel [H] ≤ 1 × 10-6, [N] ≤ 10 × 10-6. ; [T.O] ≤ 10 × 10-6; (2) decarbonization. Oxygen to the vacuum chamber of the steel surface of the water under reduced pressure, and can make the carbon content of molten steel to be reduced to 10 × 10 -6; (3) desulfurization. Injection to the vacuum chamber of the steel surface with synthetic slag, the sulfur content of molten steel to be reduced to the level of 3 × 10-6; (4) The composition of fine-tuning. Vacuum recycling of molten steel in the reduction of state and composition of adjustment to obtain an accurate composition of accuracy; (5) heating. Vacuum cycle processing can be used heating chemical heat of molten steel, molten steel to rapid warming in order to meet the requirements of the follow-up of molten steel handling. Species diversity and high quality molten steel after vacuum recycling to meet the user requirements. Steel processing unrestricted, from the very low carbon IF steel to the carbon content is high, bearing steel and high alloy content of stainless steel can be processed, and all can be satisfied with the results. The
Development and Prospects of liquid steel vacuum circulation degassing method development process, some new approaches to increase its functionality, such as the installation of jet oxygen lance deep decarburization RH-OB RH-KTB method in the upper part of the vacuum chamber. additional water-cooled oxygen lance and processing in RH at the same time dusting RH-IJ law. RH Light treatment is the use of carbon and oxygen in molten steel and vacuum conditions, while reducing the carbon and oxygen in molten steel. Vacuum recycling of carbon and oxygen in the molten steel from the balance in the atmosphere to the 50Pa balance, reduce the dissolved oxygen content in molten steel. Since Riga aluminum to the molten steel in order to achieve the stability of the aluminum recovery rate. Re-by RH circulation mixing steel composition is uniform, so that the recovery rate of aluminum in molten steel to ensure a stable control.
Vacuum circulation degassing method as an external furnace refining means the use of trend in the steelmaking process used in conjunction with the LF furnace, play the advantages of deoxidation and desulfurization advantage of LF refining process and degassing of the RH method.
In short, the RH-vacuum cycle processing After nearly 40 years of development, refining function continues to expand into a multi-functional processing equipment has grown from a simple degassing equipment. Its quick handling characteristics so that it can in conjunction with the converter's fast-paced, vacuum circulation treatment is especially suitable for rapid processing of large quantities of molten steel, and large-capacity electric arc furnace or converter can be satisfied with. Due to the advantages of vacuum-cycle approach, making it one of today's fastest-growing furnace refining equipment. It can be said that the RH of development far beyond the invention of metallurgy workers at the beginning of its expectations. Has become a degassing, deoxidation, decarbonization, desulfurization, heating, composition control, and refined ultra-low carbon steel, stainless steel smelting, the multifunction refining equipment. And RH is simple to handle molten steel volume advantages, and so has developed rapidly.
Vacuum circulation degassing of molten steel France (RH-Vacuum degassing)
a liquid steel vacuum processing technology. Jointly developed by the Federal Republic of Germany Ruhr (Ruhrstahl,) steel and Hellas (Heraeus) in 1956, so the prefix of the two companies named RH vacuum degassing method, referred to as RH France. The degassing
principle and process vacuum circulation degassing is the principle of the use of air Yang pumps. First, the molten steel inhalation of the vacuum chamber, then blown into the argon gas to the molten steel in the two immersed tube sidewall. The rapid expansion of argon gas in the molten steel in high temperature and low pressure vacuum chamber of the role of lead to the density of the mixture of molten steel and gas continue to lower the height direction along the immersed tube under the pressure difference generated by the density difference between the role of The molten steel to enter the vacuum chamber. Into the vacuum chamber of molten steel and gas mixture in a high vacuum under the effects of the release of gas at the same time, so that the molten steel into steel drops, For the removal of the gas within the steel droplets under high vacuum to vacuum release in the process of steel drops into smaller steel drops, so as to achieve a very good degassing effect. Release of gases in molten steel along the down pipe to return to the ladle.