51results about How to "Reduce inclusions" patented technology

The invention relates to the technical field of casting molds, and discloses a large GIS shell metal mold low-pressure casting mold which comprises an equipment fixing lower mold plate, a pressing mechanism, a mold body, an equipment movable upper mold plate, a movable mold plate and a casting system. The mold body is fixedly connected to the middle of the upper surface of the equipment fixing lower mold plate, the movable mold plate is installed on the upper surface of the mold body, a pouring gate is formed in the center of the lower surface of the equipment fixing lower mold plate, and the inner surface of the pouring gate is sleeved with a sprue bush. The movable mold plate comprises an equipment movable left mold plate and an equipment movable right mold plate which are oppositely arranged, a sand core is arranged in the mold main body, the casting system is arranged in the sand core, and the equipment movable upper mold plate is mounted on the upper surface of the mold main body; through cooperation of the structures, pressurization feeding can be conducted from the bottom, cooling of castings can be accelerated through metal outer mold inner cavity sand core low-pressure casting, and the technological yield of products is increased.

The invention provides tundish stuffing sand and a preparation method thereof, and belongs to the technical field of steelmaking continuous casting. The invention relates to tundish drainage sand, which is prepared from the following components in parts by weight: 40 to 60 parts of magnesite sand, 15 to 35 parts of dolomite sand, 10 to 30 parts of raw perlite, 5 to 15 parts of kyanite, 10 to 30 parts of rare earth mineral powder and a binder. The weight part of the rare earth mineral powder is 2-5, and the weight part of the binder is 1-3. The tundish stuffing sand is suitable for a stopper-free flow control pouring method, the automatic pouring rate is increased, and molten steel pollution is reduced.

The invention discloses low-boron refining slag which comprises the following raw materials in parts by weight: 45-65 parts of calcium oxide, 11-16 parts of fluorite powder, 2-10 parts of a fluxing agent, 1-3 parts of silicon dioxide and 4-12 parts of an accelerant. The refining slag comprises the following chemical components: 45 to 60 percent of CaO, 10 to 15 percent of CaF2, 5 to 15 percent of Al2O3, 2 to 5 percent of SiO2, 5 to 9 percent of MgO, 3 to 12 percent of Ce2O3 and the balance of unavoidable impurities. Due to the adoption of the technical scheme, compared with the prior art, the refining slag has the advantages of low melting point, good fluidity, capability of well adsorbing inclusions, reduction of the boron content of steel, reduction of smelting energy consumption, low cost and the like.

This utility model relates to a cooling and dust removal system for an overhead crane electrical compartment, belonging to the technical field of cooling and dust removal equipment. The technical solution of this utility model is as follows: the lower end of a PVC pipe (1) is connected to the atmosphere; a three-way filter (2) is sealed to the PVC pipe (1); the three-way filter (2), the serpentine condenser (3), and the suction fan (4) are connected sequentially through the PVC pipe (1); an internal venturi tube (5) is connected to the exhaust port of the suction fan (4); the internal venturi tube (5), the electrical compartment (6), and the exhaust fan (7) are connected sequentially; and a dust filtration device (8) is connected to the outlet of the exhaust fan (7) through the PVC pipe (1). The beneficial effects of this utility model are: improving the efficiency and quality of cooling the electrical components in the electrical compartment, ensuring the stability of the cooling process; at the same time, improving the working environment of the electrical compartment, reducing the dust contamination in the cold air and the dust in the exhaust heat, ensuring the stability of the production line control and the cleanliness of the site environment.

The invention discloses an indium-silver alloy and a preparation method and application thereof, and relates to the technical field of precious metal material manufacturing. The preparation method of the indium-silver alloy comprises the following steps: S1. heating and melting raw materials indium and raw materials silver respectively to obtain molten indium and molten silver; S2. pouring the molten silver obtained in step S1 into the molten indium obtained in step S1 and uniformly mixing them into an alloy melt; S3. cooling and solidifying the alloy melt obtained in step S2; S4. heating and melting the solidified alloy obtained in step S3 under a vacuum environment and keeping the temperature to obtain an alloy melt again, and cooling to obtain an indium-silver alloy. The present invention does not require heating all raw materials to a high temperature to uniformly disperse silver in an indium matrix, thereby reducing material loss caused by volatilization and oxidation. By repeatedly melting the alloy in a vacuum at a relatively low temperature, on the one hand, gas inclusions in the alloy are reduced and the alloy composition is made uniform, and on the other hand, the volatilization of indium in the degassing process is reduced.

The utility model relates to the technical field of pipeline iron removers, in particular to a pipeline self-unloading type permanent magnet iron remover which comprises a separation pipe, a magnetic outlet pipe is fixed on the lower side of a sending-out end of the separation pipe, a protective cover is fixed on the front side of the separation pipe, and an iron removal mechanism used for adsorbing magnetic substances in corundum is arranged in the separation pipe. And the flattening mechanism is used for flattening the adsorbed and accumulated magnetic substances. A pushing rod and a rotating sleeve are pushed through rotation of a pushing wheel, meanwhile, a moving rod and a leveling plate are driven to reset forwards through a reset frame, strip-shaped deposits composed of magnetic substances on a partition plate are leveled through the leveling plate, then hindrance generated when corundum flows can be reduced, the uniformity of corundum iron removal is improved, and the service life of the corundum is prolonged. And corundum materials mingled in the magnetic material are reduced.

The invention relates to the technical field of metal casting, and provides an iron alloy product smelting circulating casting system and method.The casting system comprises a material storage unit, a material control unit, a splash-proof unit and a circulating unit; the material control unit is used for discharging the metal liquid in a vortex mode, so that metal residues float to the surface of the liquid and are effectively removed before the metal liquid is poured into the mold; and the splash-proof unit is used for reducing the content of air carried during casting by controlling the height difference between the molten metal and the mold, and the reduction of the height difference is also used for preventing the molten metal from splashing, so that the working environment and workers are protected. Metal residues can be promoted to float upwards for impurity removal treatment during casting operation, meanwhile, the effect of quantitative control over molten metal is achieved, raw materials are saved, the qualified rate of products is ensured, in addition, gas can be effectively prevented from being brought in to form bubbles during discharging, the situation that molten metal splashes is prevented, and the service life of the molten metal is prolonged. Therefore, the working environment and workers are protected.

The invention relates to medium carbon gear steel for an automobile synchronizer. The medium carbon gear steel comprises the following chemical components in percentage by weight: 0.35 to 0.40 percent of C, 0.10 to 0.35 percent of Si, 1.20 to 1.40 percent of Mn, 0.35 to 0.50 percent of Cr, 0.025 to 0.045 percent of S, less than or equal to 0.025 percent of P, less than or equal to 0.20 percent of Cu, less than or equal to 0.030 percent of Al, 0.03 to 0.06 percent of V, 0.0020 to 0.0060 percent of Ca and the balance of Fe and inevitable impurities. The mechanical properties of the controlled-rolling and controlled-rolling strip meet the conditions that Rm is larger than or equal to 850 MPa, Rel is larger than or equal to 700 MPa, A is larger than or equal to 12%, Z is larger than or equal to 50%, the surface hardness of the rolled strip is 180-240 HBW, the Ca / S ratio is controlled to reach a reasonable range, the sulfide form in the steel has the characteristics of being small, distributed in a dispersed mode, small in length-width ratio and the like, damage to metal continuity possibly caused by formation of thick sulfide is reduced, and the machinability of the steel is improved.

This invention relates to the field of gray cast iron material preparation technology, and particularly to a method for preparing multi-alloy synergistically strengthened gray cast iron, comprising: adding steel raw materials to a smelting apparatus and heating to form molten iron; adding a chromium alloy to the molten iron, heating and holding at that temperature to form a basic mixture; determining the degree of furnace lining peeling based on the vibration frequency of the smelting apparatus, and determining the overheating risk level of the basic mixture based on the degree of furnace lining peeling; determining a target heating temperature based on the overheating risk level; determining the eddy current risk level based on the actual rotation speed; adjusting the stirring intensity during the smelting process based on the eddy current risk level; detecting the mixing ratio of the basic mixture and adjusting the amount of steel raw materials or the chromium alloy added to form a target solution; and simultaneously adding manganese nitride, alloyed tin, and ferrous sulfide to the target solution in a specified ratio to form multi-alloy synergistically strengthened gray cast iron. This invention improves the strength, toughness, fluidity, and resistance to solidification defects of gray cast iron.

The application discloses a copper-aluminum composite pipe blank preparation device and method based on bidirectional cooling control, and belongs to the technical field of metal composite solid-liquid casting. The device comprises coaxially arranged inner and outer crystallizers, a positioning base, an aluminum pipe outer mold and a split runner. The aluminum pipe and the inner crystallizer form an annular casting cavity, and the inner and outer crystallizers are provided with bidirectional cooling channels. The method comprises coaxial assembly, copper melt smelting in a protective atmosphere, split uniform casting and inner-outer cooperative forced cooling. The application precisely regulates the temperature field through bidirectional cooling, shortens the high-temperature contact time of copper and aluminum, suppresses the growth of brittle intermetallic compounds, reduces interface oxidation, pores and inclusions and improves the metallurgical bonding strength. The device structure is simple, the specification is adjustable, the production efficiency is high, the problems of poor interface bonding and many defects in traditional composite pipe preparation are effectively solved, and the device is suitable for the industrialized production of copper-aluminum composite pipe blanks in the fields of electric power and automobiles.

The invention discloses battery-grade lithium carbonate as well as a preparation method and application thereof, and the preparation method comprises the following steps: synchronously introducing a lithium-containing solution and carbon dioxide bubble water into a reaction device, and reacting to obtain lithium carbonate; the carbon dioxide bubble water is prepared by adopting the following method: simultaneously introducing carbon dioxide and water into a shear pump, and shearing and mixing to prepare the carbon dioxide bubble water. According to the method, the traditional gas-liquid reaction that carbon dioxide is directly introduced into the lithium-containing solution is creatively transformed into a gas-liquid-liquid reaction system that carbon dioxide bubble water prepared in advance and the lithium-containing solution are synchronously introduced, so that the product purity and stability are remarkably improved, and the bottleneck of a traditional intermittent process is broken through; the preparation method is simple, the production capacity and efficiency are remarkably improved, industrial large-scale production is easy to realize, and the obtained product lithium carbonate crystal is complete in growth, concentrated and controllable in particle size distribution and regular in morphology, and meets the processing requirements of high-end battery materials.

The hot-rolled wire rod for the blasting lead comprises the following chemical components in percentage by mass: 0.03 to 0.06 percent of C, less than or equal to 0.030 percent of Si, 0.20 to 0.30 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.020 percent of S, less than or equal to 0.100 percent of Cr, less than or equal to 0.100 percent of Ni, less than or equal to 0.100 percent of Cu, less than or equal to 0.0070 percent of N and the balance of iron and other inevitable impurities. The invention further relates to a production method of the hot-rolled wire rod for the blasting lead, the production method comprises a smelting process and a rolling process, and the smelting process comprises the steps of KR desulfurization and slagging-off, converter smelting, LF refining and continuous casting. The steel wire rod for the blasting lead produced through the production method is good in mechanical property, the customer drawing machining process performance is excellent and stable, and the manufactured 0.55 mm blasting lead is good in resistivity and conductivity.

The utility model discloses a metal sputtering device for manufacturing drain-source electrodes of a silicon carbide-based chip, which comprises a base, the upper surface of the base is fixedly connected with a vacuum chamber, the upper surface of the vacuum chamber is fixedly connected with a radio-frequency power supply, the upper surface of the vacuum chamber is fixedly communicated with a water-cooling sleeve, and the water-cooling sleeve is fixedly communicated with the base. The bottom surface of the water cooling sleeve is fixedly connected with a back plate, the bottom surface of the back plate is fixedly connected with a target material, the bottom surface of the vacuum chamber is fixedly connected with a driving motor, the output end of the driving motor is fixedly connected with a rotating shaft, the outer surface of the rotating shaft is fixedly connected with a bearing seat, and the upper surface of the rotating shaft is fixedly connected with a clamping device. According to the device, the thickness difference of a deposited film can be reduced and the thickness uniformity of the film can be improved by rotating the substrate, and when the magnetron sputtering gun is fixed, the metal film can be more uniformly deposited on the surface of the substrate by the rotating substrate, so that defects, inclusions and non-uniformity in the film can be reduced.

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 invention provides a cast steel material and a manufacturing method of a casting of the cast steel material. The cast steel material comprises the following raw materials in parts by weight: 0.3-0.5 part of C; the content of S is 0.005 to 0.02 percent; 0.2 to 0.4 part of Si; the content of V is 0.003 to 0.005 percent; 1.2 to 1.4 parts of Mn; 0.8 to 1.1 parts of Cr; 0.3 to 0.5 part of Mo; 0.005 to 0.03 percent of P; 0.002 to 0.005 percent of Ni (nickel); the content of the C is 0.4%, the content of the S is 0.01%, and the content of the Si is 0.3%. According to the cast steel material and the manufacturing method of the casting of the cast steel material, by reasonably adjusting the content of elements such as carbon, manganese, chromium and molybdenum, the toughness of the material is remarkably improved while the high strength of the material is kept, brittle fracture can be effectively prevented, and the reliability in subsequent use is improved; the invention has the advantages of simple process, low cost, low sulfur and phosphorus content, reduction of sulfide and phosphide inclusions, improvement of the hot working performance and cold working performance of the material, improvement of the welding performance of the material, and convenience in processing and connection of the cast steel material by reducing the sulfur and phosphorus content.

The utility model belongs to the field of vegetable cleaning, specifically is a kind of vegetable cleaning and removing mud device, including sink;The inside mounting frame of sink, the frame is inclined to be arranged, the inside rotationally connected of frame has multiple drive rolls, drive roll is installed with mesh belt, the surface of mesh belt is evenly fixed with mesh plate, the top of frame is fixed with motor, the output end of motor and drive roll are fixed, the bottom of frame is inserted into the bottom of sink;Staff pours the vegetable picked into the upper side of mesh belt, mesh belt movement is along with mesh plate to promote vegetable to move, lower vegetable is soaked into the inside of sink, and the soil inside the gap of leaf blade can be conveniently discharged in soaking and cleaning, and it is soaked and cleaned in cooperation with spraying, vegetable leaves water surface, clean water is sprayed and cleaned to spray and clean, rely on above-mentioned structure, so it can improve cleaning effect, reduce the soil mixed in the inside of leaf blade, improve cleaning effect.

The invention relates to the technical field of steel smelting, in particular to a method for preparing high-cleanliness ultra-low carbon steel from semisteel. The method comprises the procedures of converter tapping, RH refining and slab continuous casting. A ladle slag modifier is added in the converter tapping process; in the RH refining process, deoxidation alloying and adding of composite desulfurization modifier balls are sequentially carried out, so that desulfurization and inclusion modification are synchronously realized. By means of the specific ladle slag modifier, the unique double-layer composite desulfurization modifier ball and the matched refining process, the problems of deep desulfurization and high cleanliness control during ultra-low carbon steel smelting through semi-steel are successfully solved, the technical effect is remarkable, and the method is superior to a conventional process.

The invention relates to the technical field of welding materials, in particular to an electric arc welding rod for ultralow-temperature high manganese steel and a preparation method thereof.The preparation method comprises the following steps that iron powder, manganese powder, an alloy additive, a stabilizer, a deoxidizing agent and rare earth elements are weighed in proportion; uniformly mixing the weighed components with one another to obtain mixtures; the evenly mixed powder is made into particles through a pelletizer, and then the particles are pressed into the shape of a welding rod through a mold; the pressed welding rod is subjected to heat treatment; the surface of a pressed welding rod is coated with a protective layer, iron powder serves as a main carrier, manganese powder is used for improving the hardness and abrasion resistance of a material, alloy additives comprise but not limited to nickel, chromium, molybdenum, niobium and other elements and are used for enhancing low-temperature toughness, crack resistance and corrosion resistance, and stabilizers and deoxidants such as silicon and aluminum and the like are used for stabilizing the surface of the welding rod. The rare earth elements such as lanthanum and cerium are used for reducing air holes and inclusions in the welding process and improving the welding seam quality, and the mechanical property of the welding seam at the ultralow temperature can be further optimized as a special low-temperature toughness reinforcing agent and rare earth elements such as lanthanum and cerium.

The invention relates to a contact switch assembly production device, which comprises a clamping assembly, and is characterized in that the clamping assembly is used for clamping a contact switch and transferring the contact switch among a tin bonding assembly, a polishing assembly and a cleaning assembly; the vacuum adsorption assembly is used for clamping the contact switch and transferring the contact switch among the cleaning assembly, the throwing-drying assembly and the transferring assembly. The clamping assembly can drive the clamped contact switch to be transferred among different components such as the tin pick-up assembly, the polishing assembly and the cleaning assembly. The tin pick-up assembly scrapes off a layer of tin oxide film formed by oxidation of the upper surface of the tin liquid through a scraper. By means of the structural design, the tin liquid filling device can be widely applied to switch assembly lines of various types and the like, and is particularly suitable for occasions where operation tasks need to be rapidly replaced or diversified products need to be processed.

The application discloses a high-aluminum steel continuous casting method, which adopts zirconium drainage sand in a ladle to reduce the reaction between the drainage sand and molten steel, and adopts a tundish cover argon blowing technology to blow argon on the tundish cover hole or in the tundish cover refractory, so that the oxygen content of the atmosphere in the tundish is reduced from 17-21% to below 0.1%, and a large amount of secondary oxidation caused by air in the first furnace opening and the subsequent continuous casting process is avoided. The method greatly reduces the reaction between aluminum in the high-aluminum steel and the drainage sand and air, reduces the alloy element burning loss, reduces the Al2O3 inclusions, is beneficial to improving the quality of the final product, greatly reduces the nozzle clogging rate, makes the production more stable, increases the continuous casting furnace number, reduces the contact between the molten steel and air, and significantly reduces the nitrogen increase.

The utility model provides a kind of welding device, including mounting seat, and welding cavity is equipped in mounting seat;Mounting seat is equipped with first installation port and second installation port;Multiple first clamps are detachably embedded in first installation port, the shape of the first clamping hole of each first clamp is different, and first shape pipe can be inserted into welding cavity through first clamping hole;Multiple second clamps are detachably embedded in second installation port, the shape of the second clamping hole of each second clamp is different, and second shape pipe can be inserted into welding cavity through second clamping hole;Heating assembly;When a first clamp is embedded in first installation port and a second clamp is embedded in second installation port, first clamp, second clamp and mounting seat form welding cavity;Part of heat generated by heating assembly is transmitted to welding cavity through mounting seat, and part of heat is transmitted to first clamp and second clamp to heat first shape pipe and second shape pipe.The present welding device is suitable for brazing of pipe fittings with different shapes and sizes.

This invention discloses a high-temperature oxidation-resistant and corrosion-resistant coating, its preparation method, and its application. The coating comprises a NiCrAlY alloy binder layer and a YSZ ceramic layer. The NiCrAlY layer contains 19-23% Cr, 3-5% Al, 0.01-0.9% Y, with the balance being Ni. The YSZ layer is ZrO2 doped with 5-8 wt% Y2O3. The thickness of the NiCrAlY layer is 50-150 μm, and the ratio of the thickness of the YSZ layer to the thickness of the NiCrAlY layer is (1-2.5):1. By combining the properties of the NiCrAlY and YSZ layers with the spraying process, the above coating can effectively suppress metal oxidation during spraying, reduce oxide inclusions, and improve the purity and toughness of the coating. Furthermore, by considering the coating composition and structure, it can suppress the YSZ phase transformation, delay TGO growth, and improve the coating's anti-sintering properties.

The application belongs to the field of aviation composite structure production, and particularly relates to a low-pressure pre-extraction transverse shrinkage preset method for a hat-shaped stiffened wall plate tubular vacuum bag, air in the tubular vacuum bag is extracted through a vacuum nozzle connected to a vacuum device until transverse shrinkage occurs; the tubular vacuum bag after transverse shrinkage is placed in a hat-shaped stringer cap cavity, the position of the tubular vacuum bag is controlled by adjusting the air extraction pressure, and the vacuum pressure value in the tubular vacuum bag is collected in real time; the vacuum pressure value in the tubular vacuum bag is analyzed to determine the sealing performance of the tubular vacuum bag. The tubular vacuum bag in the shrinkage state is pre-placed in the stringer cap cavity, which can effectively reduce the inclusion problem in the forming process caused by poor adaptability of the tubular vacuum bag and the hat-shaped stringer cavity; a sealed vacuum device is made of different material combinations, and the air in the tubular vacuum bag is extracted to transverse shrinkage through the device, which can detect the integrity of the tubular vacuum bag in advance.

The invention relates to steel for a torsion beam and a preparation method of the steel. The steel comprises the following chemical components: 0.05 to 0.08 percent of C, less than or equal to 0.15 percent of Si, 1.2 to 1.7 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.003 percent of S, 0.01 to 0.05 percent of Nb, 0.03 to 0.08 percent of Ti, 0.1 to 0.4 percent of Cr, 0.1 to 0.25 percent of Mo, 0.01 to 0.04 percent of V, 0.0005 to 0.005 percent of Ca and the balance of Fe. [Ti] / [Mo] < = 0.6, and [Cr] + [Mo] = 0.2-0.5%; the microstructure of the steel for the torsion beam comprises ferrite and bainite. The steel for the torsion beam has the advantages that the tensile strength is larger than or equal to 650 MPa, the hole expansion rate lambda is larger than or equal to 85%, and the ductility A80 is larger than or equal to 24%.

The invention provides a low-resistance temperature coefficient precision resistance alloy and a preparation method thereof. The alloy comprises the following components: less than or equal to 0.04% of C, 1.30%-1.50% of Si, 0.30%-0.55% of Mn, less than or equal to 0.010% of S, less than or equal to 0.010% of P, 19.70%-20.50% of Cr, 3.40%-3.70% of Al, 0.60%-1.0% of Fe and the balance of Ni and inevitable impurities. The alloy has a low resistance temperature coefficient and is widely applied to the fields of aviation, aerospace and high-end instruments and meters. The manufacturing method comprises the steps that smelting is conducted in a vacuum induction furnace, a steel ingot is obtained through casting and vacuum consumable remelting, and then heating, forging and heat treatment are conducted on the steel ingot. In the smelting process, the alloy components are ensured to be accurate by controlling the pressure in the furnace, the oxygen and nitrogen content and the smelting time. And during forging, the temperature is slowly increased to 1050-1060 DEG C, heat preservation is conducted for 2-3 hours, and finally forging is conducted to the needed form. And finally, carrying out heat treatment to improve the mechanical property and the resistance temperature coefficient stability of the material. The manufacturing method can effectively improve the alloy performance, is suitable for production of precision resistor elements, and has a wide market prospect.

The invention discloses a method for preparing alloy structural steel through rare earth treatment and the alloy structural steel. The method comprises the steps that calcium carbide or aluminum is added into LF station entering molten steel for deoxidation treatment, the mass content of FeO in slag is controlled to be smaller than or equal to 1%, and the LF station entering molten steel meets the conditions that [S] is smaller than 0.02%, [P] is smaller than 0.02%, [Als] in the molten steel is smaller than or equal to 200 ppm, and the [Ca] content is smaller than 15 ppm; 3-5 min after LF station entering and slag adjusting, under the condition that the exposed surface of the molten steel surface is larger than 50%, rare earth alloy is added, electrification and soft blowing are carried out, LF station exiting is carried out, and refined molten steel is obtained; performing protective casting on the refined molten steel under protective measures to obtain an alloy structural steel casting blank; and carrying out subsequent processes on the alloy structural steel casting blank to prepare the alloy structural steel. By means of the method, the balance of the transverse performance and the longitudinal performance of the alloy structural steel can be improved, and the alloy structural steel has good mechanical performance.

The application discloses a high-aluminum high-manganese steel and a preparation method thereof. The method comprises the following steps: providing desulfurized molten iron; performing converter smelting on the desulfurized molten iron to obtain converter molten steel; performing LF refining on the converter molten steel to obtain LF refined molten steel; performing RH refining on the LF refined molten steel to obtain RH refined molten steel; and performing continuous casting pouring on the RH refined molten steel to obtain a continuous casting billet. The preparation method of the high-aluminum high-manganese steel can effectively solve the problem that AlN is precipitated and gathered at a grain boundary, the grain boundary is embrittled, the continuous casting billet has many cracks, and the rejection rate of rolled products is high.

The invention discloses a continuous casting tundish covering agent for ultra-pure steel. The continuous casting tundish covering agent comprises the following active ingredients: 40-50 parts by mass of CaO; 5-10 parts by mass of a rare earth oxide; 3 to 5 parts by mass of MgO; 8 to 15 parts by mass of SiO2; 25 to 35 parts by mass of Al2O3; and 0-3 parts by mass of carbon powder. The continuous casting tundish covering agent is suitable for producing ultra-pure steel, has the comprehensive advantages of being good in spreadability, free of red emission and crusting in the molten steel pouring process, convenient to measure temperature and sample, high in inclusion adsorption capacity and invariant in the using process, and is low in corrosion to refractory materials, stable pouring of the ultra-pure steel can be achieved, and the service life of the continuous casting tundish covering agent is prolonged. And the inclusion content and the oxygen content in the steel are ensured to be in an extremely low range.

The invention discloses a preparation method of die steel for a car lamp die, and belongs to the technical field of die steel preparation. The die steel is composed of matrix steel, a modified nano titanium carbide strengthening phase and a modified rare earth oxide complexing agent. The steel matrix comprises, by mass, 0.45% of carbon, 0.8% of silicon, 1.2% of manganese, 13.5% of chromium, 2.0% of molybdenum, 0.6% of vanadium, 1.5% of nickel and 0.3% of niobium. The other components comprise, by mass, 1.0% of a modified nano titanium carbide strengthening phase and 0.2% of a modified rare earth oxide complexing agent; and the balance of iron. According to the invention, the three materials of the matrix steel, the nano titanium carbide strengthening phase and the rare earth oxide complexing agent are synergistically modified, so that a three-in-one innovative system of'modified matrix + strengthening phase enhancement + rare earth regulation 'is constructed, and synchronous improvement of hardness, toughness, polishing performance and corrosion resistance is realized; the technical bottleneck that traditional die steel is poor in performance collaboration is solved.

The invention discloses a spot welding device for manufacturing a depth detection sensor with stable clamping, which belongs to the technical field of spot welding devices. The following scheme is proposed, which includes a spot welding machine body, and a first electrode connecting rod and a second electrode connecting rod installed on the spot welding machine body. The spot welding machine body is provided with a driving structure, and the driving structure is provided with a limiting structure for clamping the pins of the depth detection sensor; by setting the limiting structure, the connecting structure and the placement base, when the wedge blocks on the surfaces of the first limiting frame and the second limiting frame cross, they cooperate with the placement base to complete the clamping and fixing processing of the pins of the depth detection sensor and the metal wire to be spot welded, which can not only accurately lock the pin position of the depth detection sensor, but also ensure that the metal wire to be spot welded is in an ideal welding posture, effectively avoid the deviation and dislocation in the welding process, and greatly improve the welding quality and yield rate.