8results about How to "Reduce inclusion content" patented technology

This invention discloses a low-hydrogen flux-cored welding wire based on two-dimensional MXene surface self-assembly modification, its preparation method, and its application, belonging to the field of welding materials technology. The low-hydrogen flux-cored welding wire comprises a steel strip outer sheath and a flux core filled within it, the flux core being composed of metal alloy powder and modified composite flux core powder. Its preparation method includes: preparing a two-dimensional MXene colloidal dispersion using a chemical etching method; cationically modifying the insulating slag-forming powder; mixing the two and electrostatically self-assembling and coating them; after drying, mixing with the metal alloy powder; filling the steel strip; and rolling and drawing into shape. This invention constructs a three-dimensional continuous conductive network within the flux core through the MXene layer, improving arc stability; simultaneously, the MXene shell forms a physically water-blocking labyrinth, endowing the welding wire with ultra-low hydrogen characteristics; the active titanium released by the decomposition of MXene at high welding temperatures can refine the weld grains and improve mechanical properties. This welding wire can be widely used in automated gas-shielded welding processes for high-strength steel.

According to the preparation method of the gradient flow guide pipe suitable for long-time atomization, on the basis of an existing zirconium oxide flow guide pipe, raw materials with different granularities are selected, and a gradient sintering technology is adopted, so that a compact structure with the ceramic end and a loose structure with the granular middle-upper portion are prepared, and the gradient flow guide pipe is prepared; and scouring and erosion of the metal melt to the end are reduced, the content of inclusions in the powder is reduced, the purpose of long-time atomization is achieved, and the yield of the powder is further increased. According to the method, the gradient flow guide pipe with the volume density gradually reduced from the end part to the middle upper part is formed by adjusting parameters such as the granularity of raw materials and the sintering process, erosion and stripping of the end face of the flow guide pipe can be avoided, the inclusion content is reduced, long-time atomization is achieved, and the powder yield is increased. According to the method, the end face of the flow guide pipe is prevented from falling off, and the inclusion content in the prepared high-temperature alloy powder can be further reduced on the basis that the yield is improved.

The invention discloses a steelmaking process for reducing the number of inclusions of steel for an ultralow-temperature container, and relates to the technical field of steel production, and the steelmaking process comprises the following steps: controlling the oxygen content of converter tapping to be less than or equal to 600ppm, and carrying out converter tapping slagging; lime and aluminum wires are added in batches in the LF refining process for deoxidation slagging, the amount of each ton of steel slag is 12-18 kg, the binary alkalinity of the steel slag in the middle stage of LF refining is controlled to be 8-12, and the content of Al2O3 is larger than or equal to 28%; and a secondary oxidation prevention process is adopted in the continuous casting process. According to the invention, the content of inclusions in the steel can be reduced by 50%, and the performance stability of the steel at ultralow temperature can be greatly improved.

The invention relates to a preparation method of an Al-Mn series aluminum alloy flat cast ingot for a power battery shell, in particular to the preparation method of the Al-Mn series aluminum alloy flat cast ingot for the power battery shell. The invention aims to solve the problems of low performance, poor processing stability and poor surface quality of plates and strips produced by the Al-Mn series aluminum alloy flat cast ingot for the power battery shell manufactured by the existing method. Ar gas is adopted to refine and purify the melt, and the melt is purified outside the furnace; a double-rotor degassing device and a 30 + 50ppi double-stage ceramic filter are adopted, so that the content of gas and inclusions in a cast ingot is reduced, and the melt quality is improved; a double-row pulse water cooling technology is adopted, the cooling strength is reduced in the casting starting stage, ingot casting stress is reduced, and the ingot casting forming rate is increased. The method is applied to preparation of the Al-Mn series aluminum alloy flat cast ingot for the power battery shell.

The application belongs to the technical field of metallurgy, and provides a tundish for smelting to improve the purity of high-temperature alloy and a use method thereof. U-shaped filter screen, first sheet filter screen, second sheet filter screen and third sheet filter screen are sequentially arranged in the tundish from left to right, and a pouring opening is arranged at the bottom of the tundish. The tundish for smelting to improve the purity and surface quality of high-temperature alloy master alloy has a simple structure, and the tundish is designed without a baffle. The U-shaped filter screen can increase the contact area of the falling molten steel and effectively reduce splashing. The design of the baffle-free structure can intercept most of the slag and inclusions at the U-shaped filter screen and the first sheet filter screen in the initial pouring stage. The second sheet filter screen and the third sheet filter screen with small pore diameters reduce the pressure of slag blocking and avoid dam break accidents, reduce the pouring time, and reduce the temperature drop of the alloy liquid, thereby improving the purity of the high-temperature alloy. The content of inclusions in the high-temperature alloy master alloy prepared by smelting is controlled to be below 0.5.

The invention discloses high-speed steel rail steel with high fatigue performance and a preparation method of the high-speed steel rail steel. Oxide inclusions exist in the steel. The oxide inclusion comprises the following main components in percentage by mass: 50-60% of SiO2, 20-30% of CaO, 5-15% of Al2O3 and less than or equal to 20% of MgO. According to the method, oxide inclusion components are controlled within a certain range, it is guaranteed that the melting point of oxide inclusions is lower than 1400 DEG C, all inclusions are in a low-melting-point and easy-to-deform area, in the hot rolling process, the inclusions and a steel matrix can deform at the same time, and therefore the fatigue performance is effectively improved; the material has the characteristics of excellent fatigue performance and good impact performance. According to the method, the element segregation and inclusion content of the continuous casting billet are remarkably reduced, the harsh high-cycle fatigue performance can be implemented, and the high-speed steel rail with the excellent fatigue performance can be easily manufactured; the steel rail steel has the properties of high strength, corrosion resistance, excellent weldability and the like, and the fatigue property of the high-speed steel rail can be greatly improved.

The invention discloses a molten steel deoxidizing agent and a preparation method thereof, and relates to the technical field of deoxidizing agents. The molten steel deoxidizing agent comprises the following raw materials in parts by weight: 20-30 parts of calcium oxide, 60-80 parts of calcium carbide, 10-15 parts of fluorite and 2-6 parts of a modified epoxy resin binder. Polyamic acid is prepared through a copolymerization reaction of 2, 2 '-(1, 4-phenyl)-bis-(5-aminobenzimidazole) and bisphenol A dianhydride, and then bisphenol A epoxy resin is modified through bis (3-aminopropyl) terminated poly (dimethyl siloxane) to prepare organic silicon modified epoxy resin. Finally, polyamide acid is grafted to the organic silicon modified epoxy resin, and the modified epoxy resin binder is obtained. The molten steel deoxidizer prepared by the invention has the advantages of high mechanical strength, good deoxidizing effect and the like.

The application relates to the technical field of preparation of rare earth alloy sputtering targets, in particular to a terbium-based alloy target and a preparation method thereof. The terbium-based alloy target is prepared by introducing specific amounts of Cu, Al, Ce and Ga elements on the basis of Tb, and through the mutual synergistic effect among the elements, a Tb-Cu-Al-Ga-Ce alloy target with low oxygen content, fine grains, dense and uniform structure and good processing performance is obtained; further, the alloy target can improve the sputtering film forming quality, can improve the heavy rare earth utilization rate and reduce the production cost when used for grain boundary diffusion of a neodymium-iron-boron magnet, can provide a basis for realizing the synergistic promotion of coercivity and remanence, and is suitable for large-scale industrial production in high-end application fields such as new energy vehicles and energy-saving home appliances.