31results about How to "Reduce inclusion defects" patented technology

The invention relates to a steady casting technique for inhibiting liquid level fluctuation of a continuous casting crystallizer, and belongs to the technical field of continuous casting techniques inthe metallurgical industry. According to the technical scheme, the technique comprises steps as follows: A. controlling the interference amplitude in the fluctuation superposition frequency range produced by unstable crystallizer liquid level to be the lowest; B, controlling fluctuation in the low frequency range caused by unstable bulging of a casting blank; (3) improving the equipment precisionof the head of a continuous casting machine; (4) using a novel efficient double-hole nozzle or a novel pulse-controlled nozzle. The technique has the beneficial effects that the defect of subsurfaceinclusion of casting blanks due to slag entrapment of molten steel in a crystallizer is greatly reduced, and surface quality of a final product is improved; malignant production accidents such as continuous casting breakout caused by poor lubrication of crystallizer casting powder and uneven initial blank shell of the crystallizer are greatly reduced.

The invention provides a tundish covering flux, a preparation of the tundish covering flux and an application method of the tundish covering flux. The tundish covering flux comprises, by weight percentage, 1.5-4.5 % of metal aluminum powder, 1.25-2.2 % calcium powder and 93-97% low-melting-point premelting slag. The preparation of the tundish covering flux is characterized by placing the metal aluminum powder, the calcium powder and the low-melting-point premelting slag which are extracted according to a ratio into a vertical type mixer for mixing for 1-3 hours; and placing the evenly-mixed covering flux mixture in a drying oven, and drying for 1-4 hours in nitrogen protective atmosphere and at a temperature of 50-70 DEG C. The application method of the tundish covering flux is characterized by respectively adding the covering flux at 0.1-0.2 kg per ton of steel after the pouring of a first pot of steel in casting is started and when the pouring of the first pot of steel is finished; and respectively adding the covering flux at 0.05-0.1 kg per ton of steel at the beginning of the pouring of every pot and at the end of the pouring of every pot. According to the tundish covering flux, the preparation of the tundish covering flux and the application method of the tundish covering flux, oxygen and nitrogen in the molten iron are reduced remarkably, the removal rate of ferrous oxide in steel reaches 11.49 %, the T.O reduction rate reaches more than 15%, the nitrogen reduction rate reaches 20%, therefore, the inclusion defect of a slab is greatly reduced, the inherent quality of rolled plate coil is improved, and the quality objection is avoided.

The invention relates to a multi-stage impurity removing and refining method in the production process of secondary aluminum. The method comprises the following steps of: (1) pretreating, wherein pure aluminum scraps are obtained for standby; (2) removing paint; (3) preparing material; (4) drying; (5) melting; (6) mixed melting; (7) refining, degassing and deslagging; (8) adjusting components; (9) re-degassing until pinholes are qualified, standing, and removing hydrogen in the melt thoroughly; and (10) when the temperature reaches 680-720 DEG C, casting cast ingots of the secondary aluminum product. According to the method, physical and chemical methods are integrated, from screening in the pretreating process and drying and preheating for removing dirt, corrosion and oils on the surface of the waste aluminum, to the melting process and refining process for removing inserts in the waste aluminum parts, a rare earth type modifier is used, so that not only the mechanical property of aluminum melt can be improved, but also the melt can be effectively purified; and meanwhile, a refining agent and an inert gas combined refining method are adopted to control impurities and hydrogen content, so that the waste aluminum can be gradually purified.

The invention discloses a production method for IF steel for outer plates without inclusion defects, of automobiles. According to the production method, key index control is carried out on a smeltingprocess for the outer plates of the automobiles, and the inclusion defects of the plates are greatly reduced through the implementation of the key index control, so that the advantages of high yield and the like are achieved.

The invention discloses a method for casting a super-large type semi-gear ring. An outer rim whole ring open riser and an insulating riser sleeve, inner circle allowance, and external circle chilling block chilling are adopted; and circular insulating blind risers are dispersed on an inner rim and the corresponding bottom is chilled by the chilling block correspondingly so as to obtain semi-gear ring blank. In the method for casting the super-large type semi-gear ring, the outer rim whole ring open riser and the insulating riser sleeve are adopted, so that the feeding capacity of the riser isenhanced and the tissue compactness of the prepared casting is obviously improved, simultaneously floating sand and sundries can float conveniently, and the defects of sand inclusion, air holes and inclusion are reduced; the whole ring inner allowance and sand lining chilling block chilling are adopted; the inner allowance can ensure that an outer rim wall thickness center moves inward; by sand lining chilling block chilling, the tissues of the gear surface and the gear root are densified, and the defect of magnaflux inspection is reduced; and the inner allowance is not removed during furtherprocessing, the blank gear surface quality of the semi-gear ring is guaranteed, and the gear surface magnetic powder and ultrasonic flaw detection yield is improved.

The invention relates to the preparation field of steel ingots, and particularly relates to a plasma submerged arc heating method of 5 to 600-ton steel ingot riser. The method comprises the step of heating a riser after pouring a large-scale steel ingot so as to increase the heat of the riser, strengthen the feeding of the riser and improve the quality of the steel ingot; the method is suitable for plasma submerged arc heating of the riser after the steel ingot is poured, tundish plasma submerged arc heating of other alloys and submerged arc plasma heating in a smelting process. The riser of the large-scale steel ingot is heated by a plasma submerged arc heating gun; the pouring temperature and the pouring speed of the steel ingot, the plasma submerged arc heating time and the argon introducing amount are strictly controlled; the negative segregation of the steel ingot is controlled by heating the steel ingot immediately after the steel ingot is poured; the feeding of the riser is strengthened by heating the riser and rapidly building a positive temperature gradient; the loosen defect of the steel ingot contraction cavities are reduced and the defect is controlled at a first level; foreign matters can float up rapidly by the stirring function of the argon; and the total amount of foreign matters in the steel ingots is controlled to be less than or equal to a second level.

The invention discloses a directional solidification device, in particular discloses a directional solidification device and a process method for improving single crystal blade deposits, and belongs to the technical field of single crystal casting process equipment design and manufacture. Provided are a directional solidification device and a process method for improving single crystal blade deposits which can effectively improve crystal selection quality and reduce or reduce deposition of trace components. The directional solidification device includes a water cooling plate and a crystal selector arranged at the bottom of the mold shell, the bottom of the crystal selector is seated on the water cooling plate, and the directional solidification device also includes an air film isolation system, and the water cooling plate A gas film isolation layer is formed between the crystal selector and the inert gas output by the gas film isolation system. The process method adopts firstly passing gas through a gas film isolation system to form a gas film isolation layer, and then performing pouring, drawing, cooling and solidification of the single crystal blade.

The invention relates to the field of shell mold preparation of investment casting, in particular to a surface shell mold preparation method that can effectively improve small-sized concave surface casting nodules, comprising the following steps: coating preparation: preparing the first coating: parts by weight Prepare 1 part of silica sol, 0.5 to 1 part of water, 2.5 to 3.5 parts of aggregate, 0.001 to 0.005 parts of wetting agent, and add them to the first batching tank in turn, stir evenly to form the first coating; prepare the second coating: press Prepare 1 part of silica sol and 2.5 to 3.5 parts of aggregate in parts by weight, and add them into the second batching bucket in turn, stir evenly to form the second coating; pre-coat the wax model; and make the shell. By using the first paint with low viscosity and low surface tension to pre-coat the wax pattern, a wet pre-coat layer is formed between the top coat and the wax pattern, avoiding direct contact between the top coat and the wax pattern, and can Avoiding the accumulation of air bubbles on the small-sized concave surface of the wax mold caused by excessive surface tension of the surface coating, effectively reducing casting nodules.

The invention relates to a pouring cup, in particular to a filter type pouring cup. The filter type pouring cup comprises a pouring cup with an opening, wherein the upper part of the pouring cup is used for accommodating molten iron; the lower part of the pouring cup is a sand mold; a straight pouring channel communicated with the molten iron is formed in one side of the sand mold; the lower part of the straight pouring channel is sequentially connected with transverse pouring channels parallel to each other; one end part of the transverse pouring channel on the lowest layer is connected with a tail straight pouring channel which is communicated with a casting and corresponds to the straight pouring channel; and a filter screen is arranged between the transverse pouring channels parallel to each other. The filter type pouring cup is unique in structure, and can play a purifying effect on liquid metal in the casting process of large-scale castings, thereby reducing the defects of slag inclusion and impurity inclusion, lowering cost and improving product quality.

The invention relates to the technical field of valve body casting and discloses a high-temperature high-pressure ultralow sulfur-and-phosphorus valve body casting forming process. A plane in which the centers of three pipe openings of a high-temperature high-pressure ultralow sulfur-and-phosphorus valve body casting part are located is used as a parting surface, first dead heads are arranged right above the three pipe opening respectively, second dead heads are arranged above the intersected positions of all pipes of the valve body casting part respectively, a plurality of chilling blocks are arranged under the intersected positions of all the pipes of the valve body casting part respectively, the chilling blocks are separated from the casting part by chromium ores, a bottom-returning type pouring system is adopted for pouring, a cross gate is positioned under the valve body casting part and is connected with a plurality of inner gates on the same horizontal plane, and an outlet in the top end of each inner gate is formed in the wall, close to the end surface, of the corresponding pipe opening. The valve body produced by adopting the casting forming process has the good casting forming quality, the formed matrix structure is compact, the CAE (Computer Aided Engineering) simulation technique is adopted, the production period of the casting part is shortened, the casting part manufacturing process is reasonably optimized, models and molding materials can be saved, the casting part production cost is reduced and the high economic benefit is achieved.

The invention relates to a preparation method of a low-alloyed high-strength plasticity magnesium alloy material, relating to a preparation method of the magnesium alloy material. The invention aims to solve the technical problems that the cost of the existing magnesium alloy material alloy is too high, the strength and plasticity cannot be guaranteed at the same time, and the high-temperature deformation energy consumption is large. The invention adopts the method of combining low alloying and low-temperature piercing deformation heat treatment to improve the mechanical properties of the magnesium alloy. Adding low-content zinc and yttrium can produce solid solution strengthening and grain refinement effects in the magnesium matrix, combined with low-temperature piercing deformation heat treatment, the magnesium alloy can produce more dispersed precipitation while grain refinement occurs during deformation phase, the resulting dispersion strengthening effect ensures that the strength and plasticity of magnesium alloy materials are greatly improved at the same time. Through the addition of low-content alloy elements and low-temperature piercing deformation heat treatment, the technological process is simplified, the production cost can be greatly reduced, and the market competitiveness of the alloy is improved. The invention is applied to the preparation of magnesium alloys.

The invention discloses a side edge sand core provided with a dispersion pouring system. The side edge sand core comprises a sand core body, the pouring system is arranged on the sand core body, and the pouring system comprises a sprue, a runner and an ingate; and the side edge sand core is characterized in that the sand core body is divided into a main sand core body and a runner-ingate sand corehead along the central axis surface of the runner, and the runner and the ingate in the pouring system are located on the runner-ingate sand core head.

The invention relates to a steady-state casting process method for suppressing liquid level fluctuations in a continuous casting crystallizer, and belongs to the technical field of continuous casting processes in the metallurgical industry. The technical solution of the present invention is: A. controlling the fluctuation in the superimposed frequency range caused by the instability of the crystallizer liquid level has the lowest interference amplitude; B. controlling the fluctuation in the low frequency range caused by the unsteady bulge of the slab; (3) improving the continuous The equipment accuracy of the head of the casting machine; (4) Use new high-efficiency double-jet nozzles or new pulse control nozzles. The beneficial effects of the present invention are: greatly reducing the subcutaneous inclusion defects of the cast slab caused by molten steel slag rolling in the crystallizer, improving the surface quality of the final product; greatly reducing the poor lubrication of the mold mold slag and the uneven shell of the mold primary slab Vicious production accidents such as continuous casting breakouts caused.

The invention provides a design method of a pouring system for double directional hollow blades. Including: the combination of pouring system; the manufacture of the shell for the wax pattern module; the shell is placed in a three-chamber vacuum furnace to complete the pouring. The casting temperature is 1480°C and the crystal pulling speed is 4mm / min. Among them, the combination of the gating system specifically includes: establishing the diameter of the module chassis; determining the process extension of the blade; determining the position of the starting section on the module chassis; determining the height of the straight pipe in the module; connecting the filling path of the gating system; Set up runners connected with the straight pipe and sprue cup; connect the sprue cup above the straight pipe; through the design optimization of the combination of the gating system, the broken crystal of the columnar crystal at the exhaust side, Metallurgical defects such as oblique crystals and outcropping crystals, and effectively control the deformation of castings during pouring.