12 results about "Deoxidized steel" patented technology

The invention provides high-nitrogen silicon deoxidized steel and a smelting method thereof, and relates to the field of metal casting. According to the smelting method of the high-nitrogen-silicon deoxidized steel, the technology of converter, refining, continuous casting, heating, rolling and air cooling is adopted, the nitrogen content in the target molten steel is accurately controlled through Thermo-Calc software, and the high-nitrogen-silicon deoxidized steel which is good in comprehensive mechanical property and free of longitudinal cracks and other defects is stably obtained on the basis that the simple smelting technology is adopted. The metallographic structure of the high-nitrogen and high-silicon deoxidized steel obtained through the smelting method of the high-nitrogen and high-silicon deoxidized steel is pearlite and ferrite, and the grain size is 9-11 grades. The tensile strength is not less than 730 MPa, the yield strength is not less than 580 MPa, the percentage elongation after fracture is not less than 14%, and the application prospect is wide.

The invention discloses an efficient deep desulfurization method for silicomanganese deoxidized steel. The invention provides a two-step deep desulfurization process for silicomanganese deoxidized steel, aiming at solving the technical problem of weak desulfurization capacity of a steel slag system adopting a silicomanganese deoxidation process. The method comprises the following steps: 1, adding lime and a high-aluminum slag surface deoxidizer into a steel ladle during tapping of a primary smelting furnace for primary slagging and pre-desulfurization; and 2, at an LF refining station, slagging and desulfurization materials such as lime, carbon powder and calcium carbide are synchronously added to the slag surface during power transmission, and the molten steel deep desulfurization of the silicomanganese deoxidized steel is realized by utilizing good dynamic conditions of high temperature of a slag-metal interface, high alkalinity of slag, strong reducibility of the slag and the metal during power transmission and sufficient reaction of the slag and the metal. According to the method, the good desulfurization environment in the tapping period of the primary smelting furnace and the good desulfurization environment in the power transmission period of the LF refining furnace can be fully utilized, the end-point sulfur content of the primary smelting furnace is stably reduced from 0.04% to 0.0050% or below, the deep desulfurization bottleneck of the silicomanganese deoxidized steel is solved, and the method has the advantages of being easy and convenient to operate, high in efficiency and low in cost.

This invention discloses a low-carbon magnesium-carbon refractory material for smelting silicon-manganese deoxidized steel and its preparation method; the method includes the following steps: S1, preparing CMA fine powder; wherein, CMA is a limited solid solution of magnesium oxide in calcium hexaaluminate, containing Ca2Mg2Al 28 O 46 With CaMg2Al 16 O 27 Two core components: CMA fine powder is prepared from 6.93 wt% calcium oxide powder, 89.65 wt% alumina powder, and 3.42 wt% magnesium oxide powder; S2, magnesium oxide fine powder, CMA fine powder, Al powder, and B4C powder are mixed to obtain the first mixture; magnesium oxide aggregate is mixed with phenolic resin, and then natural flake graphite is added and mixed again to obtain the second mixture; S3, the first mixture and the second mixture are mixed to obtain the target mixture; S4, the target mixture is pressed into a crucible blank and cured to obtain a low-carbon magnesium-carbon refractory material for smelting silicon-manganese deoxidized steel. The low-carbon magnesium-carbon refractory material for smelting silicon-manganese deoxidized steel exhibits improved thermal shock resistance, enhanced oxidation resistance, and improved slag resistance, showing good application prospects in the smelting process of silicon-manganese deoxidized steel.

The application discloses a ladle and a method for efficiently removing inclusions in molten steel, wherein four air bricks are evenly and dispersedly arranged at the bottom of the ladle, one taphole is arranged between any two adjacent air bricks, and the air bricks are distributed at the position of 50-60% of the radius of the ladle. The method comprises the following steps: connecting the molten steel with the ladle provided with the four air bricks, adding alloy and carbon powder deoxidation alloying to the ladle in the process of tapping from a converter or an electric furnace, then adding lime and fluorite to build slag, and then transporting the molten steel to LF refining for treatment after the tapping is completed; adjusting the composition and temperature of the molten steel and the composition of the slag in the process of LF refining; after reaching the standard, carrying out calcium treatment through aluminum deoxidization, then carrying out soft stirring, directly carrying out soft stirring treatment on the silicon-manganese deoxidized steel, and directly transporting the molten steel to continuous casting for pouring after the soft stirring is completed. The application solves the problem of excessive inclusions caused by the fact that the molten steel has many dead angles in the process of soft blowing of the ladle and the inclusions are not sufficiently floated.

This application relates to a method for improving the castability of ordinary carbon steel Q235B, comprising: mixing scrap steel with molten iron and performing oxygen blowing smelting to obtain a first molten steel; performing a first deoxidation on the first molten steel to obtain a first deoxidized molten steel; performing preliminary alloying on the first deoxidized molten steel to obtain a second molten steel; adjusting the temperature of the second molten steel to a set temperature; performing a second deoxidation on the second molten steel at the set temperature to obtain a second deoxidized molten steel; performing final alloying on the second deoxidized molten steel to obtain a third molten steel; and purifying and stirring the third molten steel to obtain pure molten steel. By synergistically controlling the amount of ferrosilicon added during steelmaking and refining, and utilizing the difference in residual calcium absorption rate, calcium enrichment is achieved while precisely controlling silicon content. This method can stabilize the calcium content in molten steel without adding calcium-based alloys, promote the transformation of inclusions into liquid inclusions, thereby improving the purity of molten steel and continuous casting castability, ultimately ensuring long-term stable casting by the casting machine.

This invention discloses a method for controlling inclusions in titanium-containing ultra-low carbon steel. The steelmaking process is as follows: converter process – LF process – RH process – slab continuous casting process. After aluminum deoxidation and alloying in the RH process, low-reactive slag is added. As the vacuum molten steel circulates, this slag floats to the surface and remains at the steel-slag interface, hindering oxygen transfer from the ladle slag to the molten steel. Simultaneously, this substance has the ability to adsorb inclusions in the steel. By controlling the process parameters of the RH process, oxygen transfer from the ladle slag to the molten steel is effectively prevented, avoiding secondary oxidation of titanium and aluminum elements in the deoxidized steel and controlling the inclusion content in the steel. This invention's control method effectively prevents oxygen transfer from the ladle slag to the molten steel and avoids secondary oxidation of easily oxidized elements such as titanium and aluminum in the deoxidized steel, resulting in significant economic and social benefits.

The invention discloses a Q355B series aluminum-containing steel grade deoxidation post-treatment method, which belongs to the technical field of metallurgy, and comprises the following steps: converter tapping pre-deoxidation: in the converter tapping process, sequentially adding silicon manganese alloy, silicon iron, lime and carbon powder for pre-deoxidation; lF refining deep deoxidation: after the molten steel reaches an LF furnace, performing oxygen determination analysis, and adding aluminum blocks, aluminum wires and aluminum particles for deep deoxidation according to an oxygen content calculation result; in the LF refining process, the total adding amount of lime is controlled to be 1400 kg / 200 tons of steel, and the argon blowing stirring time is optimized to be 180 s; inclusions are controlled, specifically, low-melting-point MnO-SiO2 composite oxide is generated through silicon-manganese and silicon-iron pre-deoxidation, the average size of B-type inclusions is reduced to a first target value, and the area proportion is reduced to a second target value. According to the method, joint optimization of deoxidation, desulfurization and inclusion control is achieved in a post-deoxidation mode of'silicon-manganese and silicon-iron pre-deoxidation + LF aluminum deep deoxidation '.

This invention discloses a deoxidized steel block and a method for deoxidizing molten steel, relating to the field of molten steel deoxidation technology. The deoxidized steel block and method employ a circumferentially arranged spray structure, which rotates the steel block when magnesium gas is sprayed, thereby ensuring uniform diffusion of the magnesium gas in the molten steel. By setting the spray structure at the top of the steel block, this method essentially eliminates the requirement for a specific steel block density (magnesium content), and the magnesium gas sprayed from the top spray structure propels the steel block towards the bottom of the molten steel.

The application discloses a method for improving cleanliness of pre-deoxidized steel. The technological process of molten steel smelting is as follows: converter process-LF process-RH process-slab continuous casting process, after the end of vacuum decarburization in the RH process, a steel-slag interface barrier agent is added, and the treatment process parameters of the RH process are controlled, so that oxygen transmission from the ladle slag to the molten steel is effectively prevented, secondary oxidation of titanium and aluminum elements in the deoxidized steel is avoided, and the content of inclusions in the steel is controlled. The application effectively solves the problem of secondary oxidation of the molten steel by the ladle slag after the end of the RH decarburization of the existing pre-deoxidized steel to the continuous casting pouring process, and has remarkable economic and social benefits.

The invention discloses a method for producing high-purity iron through an industrial pyrogenic process. The method comprises the working procedures of an HIsmelt smelting furnace reduction furnace, molten iron pretreatment, electric furnace duplex, LF refining, RH vacuum treatment and continuous casting. According to the method, an HIsmelt smelting furnace is adopted to reduce molten iron, and low-silicon, low-manganese, low-phosphorus and low-sulfur initial molten iron is obtained through a molten iron pretreatment ultra-deep desulfurization and slagging-off process; electric furnace duplex smelting is adopted for further deep removal of manganese and phosphorus, slag can be discharged below zero by adopting electric furnace steel remaining operation and eccentric furnace bottom tapping, and the problem of phosphorus, silicon and manganese return during subsequent LF furnace ultra-deep desulfurization is solved; the LF furnace adopts high-alkalinity reducing slag for further ultra-deep desulfurization; oB forced vacuum decarburization is adopted in an RH furnace, residual oxygen is removed through a calcium-magnesium-aluminum composite deoxidizer after decarburization is finished, the composite deoxidizer has the advantages that oxygen in the molten steel can be removed to an extremely low level under the condition that the concentration of Al% and the concentration of Ca% are very low, the problem of castability of subsequent continuous casting of the aluminum deoxidized steel is solved through Ca in the molten steel, and 3N5-4N-grade high-purity iron can be obtained.

This application relates to a method for improving the absorption rate of rare earth elements in ultra-low carbon steel, belonging to the field of steelmaking technology. The method includes: obtaining RH-refined molten steel entering the RH refining station; decarburizing the RH-refined molten steel while maintaining a vacuum degree of less than 100 Pa during the RH refining process until the carbon content of the molten steel reaches a set carbon content, obtaining decarburized molten steel; deoxidizing the decarburized molten steel, obtaining deoxidized molten steel; chemically reacting rare earth blocks with inclusions in the deoxidized molten steel to effectively modify the inclusions, obtaining RH-refined molten steel exiting the RH refining station; and quenching the RH-refined molten steel to ensure sufficient reaction between the rare earth elements and inclusions in the molten steel. By precisely controlling various parameters during the RH refining process, efficient absorption of rare earth elements in the molten steel is achieved.

The invention discloses a low-cost deoxidation process for converter steelmaking. The low-cost deoxidation process comprises the steps of converter deoxidation, ladle deoxidation, vacuum deoxidation and the like. According to the method, a segmented deoxidation process is adopted, the carbon powder is added firstly, then the composite deoxidizer is added, and the silicon-calcium-barium-aluminum composite deoxidizer is adopted, so that compared with an existing aluminum deoxidation process, the use amount of aluminum is reduced by 50-60%, the deoxidation cost is reduced, inclusions generated by aluminum deoxidation can be deformed through calcium and barium, the yield of aluminum is 75% or above, and the method is suitable for industrial production. Oxide inclusions in the steel are obviously reduced, and after vacuum deoxidation treatment, the total oxygen content in the steel is effectively reduced, and the quality of molten steel is improved. The method has the advantages of controllable inclusion in steel, good deoxidation effect, stable product quality and low deoxidation cost.