13results about How to "Reduce secondary oxidation" patented technology

The invention discloses a spherical sealing pressure balance type steel ladle long nozzle which comprises a steel ladle collector nozzle and a steel ladle long nozzle body, the steel ladle collector nozzle, the steel ladle long nozzle body and a sealing gasket are sealed through pressing, and a plurality of argon balance channels are formed in a lower body of a spherical sealing section of the steel ladle long nozzle body. And the argon balancing channel is communicated with the external argon sealing cavity and the inner cavity of the water gap, so that the negative pressure of the inner cavity caused by molten steel circulation is balanced during use. The matched sealing mode of the steel ladle long nozzle and the steel ladle collector nozzle is improved, the tolerance of installation centering degree is improved, the sealing effect is improved, and the operation complexity is reduced; and meanwhile, the internal pressure of the long nozzle is balanced, and the risk of external air entrainment caused by internal negative pressure of the long nozzle is reduced.

This invention discloses a method for controlling sulfides in sulfur-containing gear steel, belonging to the field of metallurgical technology, including converter, LF refining, RH refining, and continuous casting processes. Converter process: molten steel tapping temperature 1630±20℃, carbon-oxygen product controlled below 0.0020; LF refining process: aluminum content in molten steel controlled at 0.035-0.045%, LF slag composition adjusted to R: 1.5-2.5, FeO+MnO: 1.0-2.0%; RH refining process: ferrotitanium added in one step to adjust the composition appropriately; Continuous casting process: argon-blown stopper rods and submerged entry nozzles are used for continuous casting, and 150-200 kg of low-basicity tundish covering agent is added to the tundish. The sulfur-containing gear steel produced by this invention can be continuously drawn for more than 10 heats, and the level of Class A inclusions can be stably controlled at A coarse ≤ 1.0 grade and A fine ≤ 1.5 grade, with a pass rate of over 99.9%.

The present application relates to the field of steel smelting, and discloses a method for removing inclusions in steel, comprising the following steps: S1, bottom argon blowing is performed on molten steel in a ladle at a first argon blowing flow rate; S2, power ultrasound is applied to the molten steel at a first frequency to refine argon bubbles; S3, power ultrasound is applied to the molten steel at a second frequency lower than the first frequency to promote diffusion of the refined argon bubbles; and S4, bottom argon blowing is performed on the molten steel at a second argon blowing flow rate lower than the first argon blowing flow rate. By refining the size of the argon bubbles and changing the motion trajectory of the argon bubbles, the present application improves the contact probability of the argon bubbles and non-metallic inclusions in the molten steel, and strengthens the removal effect of the non-metallic inclusions by the ladle bottom argon blowing process.

The invention relates to the technical field of surface treatment, and proposes a surface treatment process for a titanium alloy wire containing trace elements. The relative cutting-in and withdrawing operations of a plurality of first blades and a plurality of second blades are relatively convenient and have good practicability. During the peeling process, the process can be carried out in a state of being immersed in liquid, thereby improving the lubrication effect during the wire peeling process and reducing the generation of secondary oxidation after the wire peeling. The invention comprises a bottom plate and a main frame, the left and right ends of the bottom plate are respectively fixedly connected with a first double-bend guide tube and a second double-bend guide tube, the first double-bend guide tube and the second double-bend guide tube are both rotatably connected with a lifting frame, the two lifting frames are both slidably connected to the main frame, a synchronous frame is fixedly connected between the two lifting frames, an electric lifting rod is installed in the main frame, the telescopic rod of the electric lifting rod is fixedly connected to the synchronous frame, two linkage structures are installed in the main frame, and the two linkage structures are matched with the first double-bend guide tube and the second double-bend guide tube respectively.

The utility model relates to the technical field of steel ladle nozzles, in particular to a steel ladle nozzle with a composite structure, which comprises a nozzle body and a long nozzle, and is characterized in that the nozzle body comprises an upper section and a lower section, the upper section is cylindrical, the lower section is hemispherical, the upper section and the lower section form a whole, and a liquid outlet is formed in the middle of the nozzle body; a pouring opening is formed in the long nozzle and comprises a connector section and an extending section, the connector section is in an arc shape matched with the radius of the lower section, and the extending section is located below the connector section. The pouring gate can be in contact with the surface of the pouring gate no matter when the inclination degree of inclined pouring is small or vertical pouring is performed, so that a contact gap is small, and secondary oxidation of molten steel is reduced.

This invention belongs to the field of die casting in metallurgical processes, and particularly relates to a method for improving steel ingot yield using high-temperature CO2 gas. The method includes: 1) filling the steel ingot mold and runner with high-temperature CO2 before casting, and preheating the mold and runner to 400-700°C; 2) during casting, after the molten steel enters the ingot mold, the interior of the mold is a sealed space filled with CO2 atmosphere, and the CO2 heated by the molten steel is circulated back to the heat exchange furnace. No protective slag or heating agent is used during the casting process; 3) after casting, during the solidification process of the steel ingot, the high-temperature CO2 gas in the heat exchange furnace is used to replenish the CO2 gas in the ingot mold, resulting in slow solidification of the steel ingot and sufficient riser feeding. The advantages are: using high-temperature CO2 gas as an isolation, heat transfer, and insulation medium, and through a closed circulating heat exchange system, precise temperature and atmosphere control are achieved during the casting and solidification process of the steel ingot. By optimizing feeding and reducing waste, the steel ingot yield can be increased to over 90%.

The invention relates to the technical field of steel smelting, in particular to casting powder special for high-aluminum steel and application of the casting powder, and the casting powder contains BaO, Li2O, B2O3, CaO, SiO2, Al2O3, MgO, R2O and C; wherein the mass fraction of the BaO is 0.4%; the mass fraction of the Li2O is 2.5%; the mass fraction of the B2O3 is 0.6%; the mass fraction of the CaO is 20%; the mass fraction of the SiO2 is 38%; the mass fraction of Al2O3 is 3%; the mass fraction of MgO is 2%; the mass fraction of the R2O is 10%; the R2O is Na2O and / or K2O. According to the casting powder, by optimizing the chemical components of the casting powder and adjusting the physical properties of the casting powder, the casting powder has the low alkalinity of 0.5-0.6, the high F <-> content of 7%-8% in mass fraction of F <->, the low melting temperature, the melting point of 900-950 DEG C and the high viscosity, the viscosity of the casting powder is 0.30-0.40 Pa.s at the temperature of 1300 DEG C, and the casting powder can be used for casting powder casting. Through improvement of the performance, a series of problems caused by high aluminum content in the production process of the high-aluminum steel are solved, so that the casting powder can better meet the continuous casting requirement of the high-aluminum steel, and powerful technical support is provided for large-scale and high-quality production of the high-aluminum steel.

The invention discloses a production method of a 20Mn23AlV large flat steel ingot. The production method comprises the working procedures of EAF furnace primary smelting, LF furnace refining, VD furnace vacuum treatment and die casting pouring. In the die casting pouring process, low-carbon low-melting-point casting powder is used, and the use amount of the casting powder is 2.5-3 kg / t; the casting speed is 12-16 minutes for the body and 3-5 minutes for the cap opening. The weight of the 20Mn23AlV large flat steel ingot produced by the method is 10-30 t, the surface quality of the steel ingot is good, few inclusions exist, and the flaw detection qualification rate is high and reaches 98.5% or above.

The method comprises the working procedures of molten iron pretreatment, converter treatment, argon blowing and continuous casting, and specifically comprises the steps that a KR method is adopted for conducting desulfurization and slagging-off on molten iron, and the sulfur content of the molten iron is controlled to be lower than 0.05%; charging the desulfurized molten iron into a furnace for smelting, blowing in a top-bottom combined blowing converter, and controlling blowing end point components and carbon temperature through a sublance system; converter smelting tapping is carried out, slag washing materials and top slag lime are added for slagging, and aluminum blocks are added for primary deoxidation; recycling hot casting residues in an argon station, carrying out strong blowing and slag adjustment in an argon blowing station, carrying out slag adjustment by using a composite deoxidizer, a covering agent and aluminum powder, and carrying out calcium and aluminum wire feeding treatment after slag adjustment; and carrying out continuous casting protective pouring. Compared with the prior art, under the condition of no LF refining, the continuous casting state is stable, inclusions are well controlled, the number of continuous casting furnaces under the aluminum deoxidation process condition is increased, the problem of flocculation at a continuous casting nozzle of steel for aluminum deoxidation is solved, and the molten steel flowability is improved.

The present invention relates to a smelting method for improving castability of high-aluminum generator claw pole steel. The chemical composition of the material is calculated by weight percentage as follows: [C]: 0.05-0.08%, [Si]: 0.05-0.10%, [Mn]: 0.25-0.40%, [P]≤0.025%, [S]: 0.015-0.025%, [Cr]: 0.05-0.10%, [Ni]: 0-0.10%, [Cu]: 0-0.10%, [Al]: 0.030-0.060%, [B]: 0.0020-0.0040%, and the rest is Fe. The claw pole steel is low-silicon, low-carbon, high-sulfur, and high-aluminum steel. During casting, problems such as nozzle nodules and stopper rod rising leading to pouring interruption are easily encountered. The present invention can improve the cleanliness of molten steel and ensure castability by designing a reasonable smelting process.

The application discloses a kind of inclusions control method of sulfur-containing aluminum control steel smelting, including S1, electric furnace tapping: aluminum block, alloy, lime, refining slag are sequentially added;S2, LF refining: control refining end point target slag system is: basicity R: 2~3.5, Al2O3: 7%~13%, TFe≤0.5%;S3, VD vacuum refining: molten steel is to station after blowing nitrogen gas and increasing nitrogen, after breaking vacuum, argon gas is blown and stirred, and after breaking vacuum, the feeding sequence of wire is silicon nitride wire, calcium wire, aluminum wire, titanium wire and sulfur wire;S4, large square billet continuous casting.The application has the advantages of effectively reducing the number of high melting point inclusions, improving the purity of molten steel, realizing multi-furnace continuous casting of molten steel, improving production efficiency and stably improving product quality.

The utility model discloses an integral casing pipe structure for pouring, which comprises a casing pipe main body, a pouring hole I and a pouring hole II are arranged in the casing pipe main body to form a double-hole casing pipe structure, the pouring mode during pouring is double-hole intrusive water gap pouring, and both the pouring hole I and the pouring hole II are through holes. By using the integral sleeve, nitrogen and oxygen increase of molten steel from a tundish to a crystallizer can be effectively avoided, secondary oxidation of the molten steel is reduced, and the quality of high-quality special steel products is improved. According to the technical scheme, the whole pipe is used for casting, particularly the double-hole sleeve is used for casting, so that the flowing state of molten steel injection flow can be effectively adjusted, the product quality is improved, and the casting stability can be kept in the unstable casting process.

This invention relates to the field of tundish covering agent technology, and specifically discloses a double-layer tundish covering agent pellet, comprising the following components by mass percentage: limestone 30%–37%, dolomite 18%–28%, lightly calcined magnesia powder 10%–15%, expanded perlite 22%–30%, expanded graphite 1%–4%, binder 1%–3%, and magnesium chloride 2%–4%. The purpose of this invention is to solve the problem of potential quality hazards in molten steel caused by the melting of rice husks in traditional double-layer heat-insulating covering agents during steelmaking.