Electric Furnace Steelmaking and AOD Furnace Refining Technology

Electric Furnace Steelmaking and AOD Furnace Refining Technology

As the shining pearl of modern steelmaking technology, electric furnace steelmaking occupies an important position in the steel industry with its high efficiency and flexibility. It cleverly uses the hot energy generated by the electric arc to push the temperature in the furnace to an astonishing 4000℃, providing unparalleled conditions for the smelting of steel. This process is like a flame in the hands of a magician, turning scrap steel into a soft and flexible one.

The art of electric furnace steelmaking lies in its exquisite stage division: melting period, oxidation period and reduction period, which are closely linked to each other and jointly interpret a gorgeous chapter of dephosphorization and desulfurization. Compared with the traditional blast furnace converter method, electric furnace steelmaking has the unique advantage of using scrap steel as raw material, and has shown significant savings in infrastructure investment. With the continuous advancement of direct reduction technology, the addition of metallized pellets has injected new vitality into electric furnace steelmaking, promoting its wide application in the fields of high-quality steel, alloy steel and stainless steel smelting. Electric furnaces are not only the pioneers of stainless steel smelting, but also the heroes behind the scenes of molten steel, dephosphorization and desulfurization.

The AOD furnace refining technology is a bright new star in the field of stainless steel refining. The argon oxygen decarburization method has won the favor of the industry with its simple equipment, convenient operation, strong adaptability, and relatively low investment and production costs. In the AOD furnace, blast furnace molten iron and electric furnace molten steel are intertwined. By accurately blowing in a mixed gas of O2, Ar or N2, the fine decarburization of the molten steel is achieved. At the same time, the clever use of the feeding system is like a chef who is proficient in mixing, accurately adjusting the composition and temperature of the molten steel, and finally cooking stainless steel dishes of excellent quality.

The smelting principle of the AOD furnace is deeply hidden in the transportation and regulation of the mixed gas. The gas starts from the oxygen production workshop, goes through pipeline transportation, metering, pressure reduction, regulation and mixing, and finally enters the furnace with the flow rate and proportion required by the process. At the beginning of smelting, oxygen penetrates the double-layer water-cooled oxygen blowing pipe like a sharp sword, pointing directly at the metal molten pool, and starts the battle of decarbonization. During refining, the side gun turns into a delicate brush, using the mixed gas as ink to gently depict the beautiful picture of decarbonization and chromium preservation. The synergistic effect of the three side guns is even more powerful, enhancing the oxygen supply intensity, improving the metal material recovery rate, and shortening the smelting time. The stable and reliable control system is like a rigorous commander, ensuring the orderliness of the entire smelting process and the stability of product quality.

LF furnace, as a key equipment in steel production, shines in the field of off-furnace refining with its unique refining function. It is like an elegant variant of the electric arc furnace. Through the stirring of white slag in the barrel and argon in a low-oxygen environment, combined with the gentle heating of graphite electrodes, the fine refining of the molten steel in the primary refining furnace is achieved. Argon stirring, like a diligent cleaner, promotes the chemical reaction between slag and steel; and arc heating, like warm sunshine, provides the necessary temperature compensation. With the joint efforts of the two, the oxygen and sulfur content in the steel has been reduced, and the inclusions have reached the ASTM rating of O~O.1. The LF furnace can not only work hand in hand with the electric furnace or oxygen converter to produce high-quality alloy steel; it is also a powerful assistant in the continuous casting workshop, especially in the alloy steel continuous casting production line, playing a key role in controlling the composition, temperature and preserving molten steel. Therefore, the LF furnace has become an indispensable part of the LD-LF-RH-CC (continuous casting) joint production line, contributing an important force to the production of high-quality steel.

The vacuum treatment technology of the VD furnace is another unique skill in the field of molten steel treatment. It places the molten steel from the electric furnace or converter in a closed vacuum tank, and stirs the argon gas at the bottom of the ladle to start a feast of impurity removal. Impurities such as hydrogen and nitrogen leave under the call of the vacuum; the carbon-oxygen reaction cleverly removes oxygen; and the reaction of the alkaline top slag with the molten steel effectively reduces the sulfur content. In addition, the VD furnace is like a careful blender, evenly adjusting the composition and temperature of the molten steel, laying a solid foundation for subsequent processing.