70results about How to "Promotes buoyant removal" patented technology

The invention discloses a smelting method capable of reducing inclusions of spring steel. The smelting method includes the following steps of (1) smelting through a high carbon withdrawing process; (2) argon blowing; (3) refining in an LF furnace; (4) vacuum treatment; (5) LF soft blowing; and (6) spring steel rolling. Especially, aluminum-free deoxidation is adopted during smelting through the high carbon withdrawing process, and a low-alkalinity slag process is adopted during refining in the LF furnace. According to the smelting method capable of reducing inclusions of spring steel, on the basis of researching thermodynamics and kinetics for separation out of inclusions, the content of oxides is lowered by controlling the deoxidation depth during smelting, the low-alkalinity slag process facilitates plasticization of inclusions, the plasticized inclusions can easily aggregate and grow up, flotation removal is facilitated during soft blowing in secondary refining, and therefore the purpose of controlling the level of nonmetal inclusions of spring steel is achieved; and the problem of judgment amending caused by exceeding of inclusions is completely solved, and the production cost is greatly lowered.

The invention discloses a production method for aluminum killed molten steel containing sulfur, and the production method mainly solves the technical problems that control over impurities in the aluminum killed molten steel containing the sulfur produced by converter smelting in the prior art is difficult, and normal casting of a slab continuous casting machine cannot be met. According to the technical scheme adopted by the invention, the production method for the aluminum killed molten steel containing the sulfur comprises the following steps of: adopting a top-bottom combined blowing converter to smelt molten steel, and adding the following raw materials of metal main ingredients including, by weight, 92%-100% of molten iron and the balance light waste steel; controlling slagging auxiliary materials in a converter smelting process, and adding the converter slagging auxiliary materials to conduct slagging while introducing oxygen to ignite by a converter oxygen lance; controlling a converter smelting end point, and detecting w[C] in molten steel at the converter smelting end point; immediately tapping after converter blowing is ended; transporting molten steel to a refining furnace for controlling the temperature of the molten steel and regulating alloy components; and transporting the molten steel to an RH furnace to refine. The aluminum killed molten steel containing the sulfur is produced by the method and is good in quality and good in pourability.

The invention discloses an independent adjustable combined electromagnetic braking device and method for controlling flowing of molten steel. The device comprises a crystallizer, wherein horizontal magnetic poles are arranged on the wide surface of the crystallizer, horizontal excitation coils are arranged on the outer sides of the two horizontal magnetic poles correspondingly, a magnetic yoke isarranged on the crystallizer in a sleeve mode, the magnetic yoke corresponds to the horizontal excitation coils, the inner surface of the magnetic yoke is in clearance fit with the outer surfaces of the horizontal excitation coils and the outer surface of the crystallizer, vertical magnetic poles are arranged on the positions, above the horizontal magnetic poles, of the wide surface of the crystallizer, vertical excitation coils are arranged between the crystallizer and the vertical magnetic poles, the horizontal magnetic poles are not connected with the vertical magnetic poles, horizontal iron cores or vertical iron cores are arranged on the two groups of vertical magnetic poles, one end of an immersion type water opening is connected with a middle bag, and the other end of the immersiontype water opening extends into the crystallizer. The device is formed by combining one pair of horizontal magnetic poles and two pairs of vertical magnetic poles, and the current intensity applied bythe excitation coils on the three pairs of magnetic poles can be independently regulated and controlled according to the actual flowing state of the molten steel in the crystallizer.

The invention discloses a preparation method for a molten steel purifying agent, and belongs to the technical field of steel purifying and smelting. The preparation method comprises the following steps of: mixing active ingredients with adhesion components to obtain a purifying agent mixture, wherein a mass ratio of the active ingredients to the adhesion components is (5-10) to 1, the active ingredients comprise metal aluminum, lime powder, silicon carbide powder, titanium dioxide and biomass, and the adhesion components comprise kaolin and sulfonated phenolic resin; and under action of a briquetting machine or a pelletizer, adhering and pelletizing the purifying agent mixture to obtain a granular purifying agent, and drying and cooling the granular purifying agent for later use. The purifying agent prepared by the preparation method reduces content of oxygen in molten liquid, and CO gas generated by reaction promotes floating removal of inclusion, so that removal of inclusion in steel is promoted; molten liquid treated by the purifying agent is relatively small in residual inclusion dimension and is uniform in distribution; and the active ingredients are matched with the adhesion components, so that the purifying effect of molten steel can be improved.

The invention discloses a submerged nozzle for special-shaped blank casting and an arrangement mode thereof. The submerged nozzle is annular, and a side wall with a hollow inner cavity is formed. A circular first opening is formed in the upper end face of the side wall, and a T-shaped second opening is formed in the lower end face of the side wall. A vertical part and a horizontal part which is connected with the middle of the vertical part are arranged on the edge of the second opening, the center of the circle of the first opening and the center of the second opening are both placed on the axis of the side wall, and the area of the first opening is equal to the area of the second opening. The hollow inner cavity is formed by correspondingly extending to the edge of the second opening from the edge of the first opening in the quasi-generatrix direction in a cut-through mode. According to the scheme, a stable and even flow field can be formed in a crystallizer, particularly the temperature and component uniformity in the transverse direction of the heat center of molten steel and the cross section of the crystallizer are improved, floating removal of nonmetallic inclusion in the molten steel and primary blank shell growth can be facilitated, and casting blank texture and surface quality are improved.

The invention discloses a pneumatic rotational flow upper nozzle base brick for continuous casting tundish. The pneumatic rotational flow upper nozzle base brick comprises breathable bricks, an air chamber, an air inlet pipe and a upper nozzle base brick body; the breathable bricks are located on the upper portion of the upper nozzle base brick and arranged in the upper nozzle base brick body; each breathable brick comprises an upper fan-shaped breathable portion and a lower circular-ring-shaped breathable portion; the air chamber is located between the lower circular-ring-shaped breathable portions of the breathable bricks and the upper nozzle base brick body and communicates with the breathable bricks; and one end of the air inlet pipe is connected with the side of the air chamber, and the other end of the air inlet pipe penetrates out of the side face of the upper nozzle base brick body and is connected with an external connecting pipe. According to the pneumatic rotational flow upper nozzle base brick for the continuous casting tundish, argon is blown into the fan-shaped breathable bricks to form an annular air curtain, and inclusion floating and removing are promoted; and meanwhile, molten steel rotational flow channels are formed in spiral gaps of the fan-shaped breathable bricks, rotational flowing of molten steel in a tundish nozzle is achieved, adhesion between inclusion and the inner wall of the tundish nozzle is reduced, collision between small bubbles and the inclusion which enter the tundish nozzle is promoted, and the effects of purifying the molten steel, preventing tundish nozzle blocking and reducing casting blank rim holes are achieved.

The invention discloses a smelting method and a production process of clean steel and belongs to the technical field of steelmaking. Molten iron is subjected to desilicication and desulphurization treatment through molten iron pretreatment and then is smelted in a converter; in the tapping process, a steel ladle slag modifier is added into a steel ladle; the steel ladle slag modifier comprises light-burning dolomite; the content of P and S in the treated molten iron is controlled to meet the relation of P<=0.006% and S<=0.008%; and at the terminal stage of RH refining, a purifying agent with the adding quantity accounting for, by mass, 0.05-1.5% of the molten steel is added into the molten steel. The molten iron is subjected to desilicication and desulphurization treatment through molten iron pretreatment and then is smelted in the converter, in the tapping process, the steel ladle slag modifier is added into the steel ladle, and at the terminal stage of RH refining, the purifying agent is added into the molten steel, so that the purifying effect of the molten steel is improved, and the smelting quality of the clean steel is further improved.

The invention discloses a molten steel purifying agent for removing inclusions in molten steel, and belongs to the technical field of net steel smelting. The purifying agent is granular, and comprises an effective component and an adhesive component; the mass ratio of the effective component to the adhesive component is (5-10): 1; the effective component comprises metal aluminum, lime powder, silicon carbide powder, titanium dioxide and biomass; the adhesive component comprises kaolin and sulfonated phenolic resins; the purifying agent is spherically granular; and the granular diameter is 5-10 mm. The oxygen content in the molten steel is reduced by the purifying agent; CO gas generated by the reaction accelerates the upward floating removal of the inclusions and the removal of the inclusions in the steel; the inclusions remained in the molten steel treated by the purifying agent are smaller in size and uniformly distributed; the content of the inclusions in the steel treated by the molten steel purifying agent is prominently reduced; the inclusions in the steel are denatured; and the purifying effect of the molten steel is obvious.

The invention relates to a four-hole circulating bottom argon blowing method for rapidly mixing molten steel. Four argon blowing holes are uniformly distributed in the inner diameter 0.5-0.7R positionof the bottom of a steel ladle, when steel ladle bottom blowing begins, the four argon blowing holes blow argon in sequence and in a circulating mode, the blowing flow of the argon blowing holes is changed based on the sine rule, the blowing flow range of a sine wave peak is from 8 pi to 20 pi m<3> / h, the total blowing flow of the four argon blowing holes is 16-40 m<3> / h, and the cycle time of circulating argon blowing is 1-4 t, wherein the t is the time needed by the argon from the argon blowing holes to reach the molten steel level. According to the method, an argon flow channel can be effectively prevented from being formed in the molten steel, and the kinetic energy of the argon is fully utilized to stir the molten steel; and a higher blowing rate can be generated, stirring strength is increased, the volume of dead zone in the steel ladle is further reduced, and components and temperature of the molten steel are rapidly and uniformly distributed. The method can fully use the stirring effect of the argon on the molten steel, shorten molten steel mixing time, reduce smelting cost and improve refining efficiency.