173results about How to "Avoid crack defects" patented technology

The invention provides a casting method for an impeller made of a super duplex stainless steel 5A material. The method comprises the steps of preparation of a casting mould and a sand core, specifically, the casting mould and the sand core are prepared in the manner that alkaline phenolic resin is added to crude sand, the casting mould is provided with an impeller cavity for storing the sand core, and a dead head is internally provided with a ceramic foam filter; casting and pouring; and sand shakeout and heat treatment of a heat-filling furnace, and an impeller finished product is obtained. The temperature ranges of precipitation of brittle phases including Eta, Chi and Sigma can be avoided, precipitation of the brittle phases by an impeller casting structure is avoided, crack defects of an impeller casting are overcome fundamentally, density of the casting structure can also be guaranteed, and the yield rate of a casting finished product can be increased to 96% or above; and meanwhile, the casting production cost is greatly lowered as the technological yield is increased, and the heat-filling furnace process is implemented.

The invention discloses an ultrahigh-alkalinity crystallizer mould flux special for high-pulling-rate peritectic steel. 38%-42% of CaO, 25%-29% of SiO2 and 7%-10% of F- are adopted to improve the crystallization capacity of the mould flux, reduce stress concentration and improve lubrication; 2%-5% of MgO and 2%-5% of Al2O3 are adopted to improve the fluidity of a flux film and reduce cracks; an excellent heat transfer coordination and heat transfer control effect is achieved by adopting the mould flux with the alkalinity ranging from 1.35 to 1.52, 25%-29% of SiO2, 2%-5% of Al2O3 and 2%-5% of MgO; the effects of effectively controlling the melting rate to guarantee melt flux feeding and preventing subsurface blowholes can be achieved with the carbon proportioning range of 4%-7%. Raw materials for preparing the ultrahigh-alkalinity crystallizer mould flux can be easily obtained, the flux consumption ranges from 0.32 kg per ton of steel to 0.38 kg per ton of steel, and cost of per ton of steel is low; on-spot practical application indicates that the mould flux can be well spread in a crystallizer and be evenly and stably melt and is high in casting percent of pass.

The invention provides a manufacturing method of a flexible AMOLED (active matrix/organic light emitting diode) display screen and a conductive adhesive film layer. The flexible AMOLED display screen is provided with a flexible substrate (21), a plurality of bonding terminals (22), a conductive adhesive film layer (23) and an IC (integrated circuit) chip by layers from bottom to top; the conductive adhesive film layer (23) comprises a plurality of conductive thin films (231) and a plurality of insulation thin films (232), which are sequentially and alternatively staggered in the extending direction of the IC chip (24); the conductive thin films (231) are used for replacing the conductive particles which are dispersed in the existing anisotropic conductive adhesive thin films and only can be broken by larger stress to conduct the IC chip (24) and the bonding terminals (22). The manufacturing method can solve the problems of cracks of the flexible substrate and failure to conduct the IC chip and the bonding terminal due to the unbroken conductive particles in the bonding process of the prior art.

The invention discloses a magnesium alloy wheel forging forming method. The technological process of the magnesium alloy wheel forging forming method can be summarized as ''twice-squeezing and once-rotating''. The magnesium alloy wheel forging forming method is characterized by comprising the steps that (1), heating is conducted, wherein a round magnesium alloy blank is heated to the forging temperature, and the temperature of a die is controlled to be equal to that of the blank; (2), primary squeezing is conducted, wherein primary forming of spokes and a rim is completed in a closed backward squeezing way, but an outer rim is not formed; (3), final squeezing is conducted, wherein the outer rim is finally formed in a closed forward squeezing way, and backward-squeezing final forming of the rim portion are completed at the same time; and (4), inward rotary squeezing for forming is conducted, wherein flaring of the rim and forming of a folded edge of an inner rim are completed through inward rotary squeezing. The magnesium alloy wheel forging forming method has the advantages that the technological process is simple; the streamline is smooth; the production efficiency is high; the utilization rate of materials is high; the defect of cracking can be effectively avoided in the forming process; and the volume production can be achieved easily.

The invention discloses a welding method for conducting build up welding through stellite alloy, and belongs to the field of welding. The method includes the steps that the first time of heat preservation is conducted after a build up welded workpiece is preheated; build up welding is conducted through a welding wire and manual argon tungsten-arc welding by means of the build up welded workpiece after the first time of heat preservation so that the welding wire can form a build up welded layer at the weld joint of the build up welded workpiece, wherein it is ensured that the build up welded workpiece is 200 DEG C to 300 DEG C in the build up welding process, and the welding wire is made of stellite alloy; after welding is completed, thermal treatment is conducted on the build up welded workpiece, wherein the initial temperature of thermal treatment is 200 DEG C to 300 DEG C, and the second time of heat preservation is conducted after the initial temperature of thermal treatment is raised to 850-870 DEG C at the speed of 80 DEG C per hour; and cooing is conducted. According to the method, the build up welded workpiece is preheated, the cooling speed of the weld joint can be decreased through preheating, the welded build up welded workpiece can be slowly cooled, a product is prevented from generating welding cracks especially cold cracks, and meanwhile it can be ensured that the build up welded layer has high strength.

The invention discloses a method of improving center segregation quality of hypo-peritectic steel casting slabs, and belongs to the technical field of slab continuous casting. According to the method,two pairs of electromagnetic stirring rollers are arranged in a secondary cooling zone, and the two pairs of electromagnetic stirring rollers are installed at corresponding positions 3.5 to 8 m perpendicular distance from a crystallizer meniscus; the two pairs of electromagnetic stirring rollers are arranged in a three-ring manner; magnetic field directions generated by the electromagnetic stirring rollers are changed at intervals of 15 seconds; the current of the first pair of electromagnetic stirring rollers is 200 to 300 A, and the frequency is 2 to 4 Hz; the current of the second pair ofelectromagnetic stirring rollers is 300 to 400 A, and the frequency is 3 to 5 Hz; and meanwhile, the dynamic soft reduction technology is employed for processing nearby a solidification end point, thereduction interval of dynamic soft reduction is arranged at a position that the solid fraction of each casting slab is 10 % to 80 %, the reduction rate is 0.8 to 1.5 mm/m, and the total reduction amount is 4.0 to 5.5 mm. The method disclosed by the invention is capable of stably controlling center segregation of the hypo-peritectic steel casting slabs to be C 0.5 to C 1.5; hot charge rolling is realized on all the hypo-peritectic steel casting slabs; and tensile layering and rupturing of hot-rolled coils (plates) is eliminated.

The invention relates to a continuous combined extrusion blooming method for a difficult-to-deform superalloy ingot. According to the method, the guidance positioning effect of a reducing extrusion female die is utilized to perform reducing extrusion, upsetting deformation and forward extrusion continuous combined extrusion one-off forming in an extrusion cylinder, so that multi-heating-number upsetting blooming in an existing process is omitted. Firstly, part of the cast structure of the difficult-to-deform superalloy ingot is broken through small-deformation reducing extrusion and upsettingdeformation, so that the difficult-to-deform superalloy ingot can generate plastic deformation which is large enough to realize recrystallized grain refinement; meanwhile, the radial constraint effectapplied to the blank by the extrusion cylinder and a cavity of the reducing extrusion female die effectively prevents buckling deformation in the upsetting process of the superalloy ingot with a large height-diameter ratio; and finally, through extrusion deformation with a large extrusion ratio (8:1-12:1), the cast structure with a thick core is fully broken, and a uniform recrystallization behavior is generated on the surface and the core of a bar, so that the uniform fine-grain superalloy bar with the grain size reaching the 7-9 level is obtained.

The invention relates to a roller shaft assembly having an air cooling structure and used for a crushing machine and an air cooling roller shaft type crushing machine. The roller shaft assembly comprises a core pipe and a roller sleeve which is fixedly sleeved with the core pipe and is composed of a plurality of parallel gear-shaped rollers, wherein one end of the core pipe is connected with a driving speed-reducing motor by a driving end shaft head and the other end of the core pipe is supported on a bearing seat by a follow-up end shaft head. The roller shaft assembly is characterized in that an inner end opening of the follow-up end shaft head is connected with an air guide pipe; each gear-shaped roller is internally provided with a roller air passing channel and forms a roller sleeve air passing channel; one end, which is close to a follow-up end of the core pipe, of the roller sleeve is provided with an air inlet end sleeve; the other end, which is close to a driving end of the core pipe, of the roller sleeve is provided with an air outlet end sleeve with a plurality of air outlets; the core pipe is provided with a core pipe air passing hole which is communicated with the follow-up end air inlet end sleeve and the air passing channel of at least one gear-shaped roller. The air cooling roller shaft type crushing machine is characterized in that the roller shaft assembly having the air cooling structure is adopted. The roller shaft assembly having the air cooling structure and the air cooling roller shaft type crushing machine have the advantages that the product performance is improved, the cost is reduced and the service life is prolonged.

The invention belongs to the technical field of material surface reinforcing and particularly relates to a method for preparing a TiC/TiB wear-resisting coating in an in-situ manner through laser cladding. According to the method, mixed powder is used as a raw material, the raw material is manufactured into slurry and then coats on a substrate, drying is carried out, and then the TiC/TiB wear-resisting coating is generated on the substrate in an in-situ manner through laser cladding. The mixed powder comprises the following components including, by mass percentage, 10%-40% of boron carbide powder and 60%-90% of pure titanium powder. The obtained coating is compact in texture, reinforced phase distribution is compact, and the coating shows good metallurgical bonding with a base material. The micro-hardness value can reach about 900-1100 HV0.2, and the wear-resisting performance is improved remarkably.

The invention relates to an investment casting process for a super duplex stainless steel pump housing, and belongs to the technical field of investment casting processes. Castings are prepared by rawmaterial preparation, preheating, melting, shell roasting, pouring and heat treatment. By means of the investment casting process for the super duplex stainless steel pump housing, the CD3MWCuN superduplex stainless steel pump housing can be manufactured by an ordinary 200-kg medium frequency induction electric furnace. The mechanical properties of the castings manufactured are excellent, and the test results of grain boundary corrosion and RT flaw detection of a weld seam are qualified, so that the crack defects of high performance pump housing precision castings are overcome.

The invention provides a device for improving pipe internal-pressure forming limit and a method for improving pipe internal-pressure forming limit by utilizing the same, which relate to a device and method for improving pipe internal-pressure forming limit and solve the problems of poor deformation uniformity, cracking due to the excessive thinning of a local part and low room-temperature forminglimit in the traditional pipe internal-pressure forming process. In the device provided by the invention, a constraint sleeve is arranged at the middle part of the outer side wall of a pipe or a die is arranged outside the pipe; in the method provided by the invention, the constraint sleeve is arranged at the middle part of the outer side wall of the pipe or the die is arranged outside the pipe, a filler is added into the gap between the die and the pipe, the pipe is fixed on a die frame with the two ends sealed, an internal pressure is introduced into the inner cavity of the pipe, and forming is finally carried out. In the invention, a back pressure is applied to the outer side of the pipe, so that the stress state of the pipe at a sectional part subjected to the maximum deformation is changed into a two-pulling and one-pressing mode from a two-pulling mode, thereby avoiding the possibility that a cracking defect is caused as the wall thickness of the part is excessively thinned, improving the room-temperature forming limit, and increasing the expansion ratio to 30-45%.

The invention relates to a forming device and method for a precise hollow component with a rectangular section. The forming method includes that step 1, preparing a die, mounting an anti-deformation structure on the die, and mounting a check valve at a punch; step 2, placing an initial tube blank in a die cavity, closing the die and sealing the ends; step 3, filling the tube blank with fluid medium; step 4, enabling the anti-deformation mechanism to move in the opposite direction to form a micro-pedal shape; step 5, enabling the anti-deformation structure to return to the initial position to flat the concave part of the pedal shape; repeating the steps 4 and 5 to form the needed shape; relieving the inside fluid pressure, and opening the die to take out the component. According to the forming method for the high-precision hollow component, the die is provided with the anti-deformation mechanism to achieve the repeated and accumulative use of the pedal shape, the friction rolling effect is eliminated, the forming pressure is lowered, the disadvantage of break is avoided, the wall thickness uniformity is improved, and accordingly the high-precision requirements for the dimension precision and wall thickness uniformity of the high-precision hollow component used for the aerospace and other fields are satisfied.

The invention relates to a milling and grinding tool capable of realizing high-efficient machining of an inorganic composite material. The milling and grinding tool structurally comprises a cutter handle, a tool withdrawal groove, a chip groove, an electroplating and cutting part, and a chip space, wherein the diameter of the cutter handle of the milling and grinding tool is 10mm; the length of the cutter handle is 55mm; the surface roughness of the cutter handle is less than or equal to 0.16mu m; the total length of the milling and grinding tool is 70mm; the width of the electroplating and cutting part in the milling and grinding tool is 10mm; the diameter of the chip space is 5mm, and the depth of the chip space is 2mm. In order to meet the requirement of chip removal, four spiral grooves with certain spiral angles are uniformly distributed on the milling and grinding tool; and according to machining requirement, diamond abrasive particles with different particle sizes are electroplated on the electroplating and cutting part of the milling and grinding tool. According to the milling and grinding tool with the special structure, multiple cutting and micro cutting in milling and grinding can be fully utilized to remove the inorganic composite material, the tool can be used for removing large amount of remains, and the geometrical shape accuracy of brittle inorganic composite material machining is ensured.

The invention discloses a casting process for a high-temperature water-pressure-resisting combined flange. The cast high-temperature wear-resisting combined flange mainly comprises a flange body. The flange body is composed of a first flange plate and a second flange plate. The shape and the size of the second flange plate are the same as those of the first flange plate. The first flange plate and the second flange plate are each of a saddle-shaped structure. Threaded holes and through holes are evenly distributed in the first flange plate and distributed at intervals. The two ends of the first flange plate extend outwards to form fixing edges. Fixing holes are formed in the fixing edges. At least two lug plates are arranged on the edge of the outer side of the first flange plate. The first flange plate and the second flange plate are connected together in a fastened manner through bolts after butting the fixing holes in the fixing edges, and the first flange plate and the second flange plate are connected in the fastened manner to form a mounting hole. The casting process is simple and easy to implement. The cast combined flange is simple in structure and has good high-temperature water-pressure-resisting performance, the service life of the flange is prolonged, and cost is lowered.

The invention relates to a preparation method of a dispersed strengthened platinum rhodium and platinum composite material and belongs to the technical field of metal materials. The method composites the dispersed strengthened platinum rhodium and the platinum to obtain a novel dispersed strengthened platinum rhodium material. A dispersed strengthened platinum rhodium and platinum composite material product is obtained by burdening, high frequency smelting, vacuum smelting, casted rolling piece cutting, oxidation processing, composite machining, hot forging, cogging and rolling. The preparation method of the dispersed strengthened platinum rhodium and platinum composite material effectively prevents expansion of crack defects under the condition of guaranteeing strength and toughness of the dispersed strengthened platinum rhodium material, and can enable elongation percentage of the platinum rhodium material to be controlled.

The invention relates to a casting and cooling system and a cooling method of a high-carbon steel thin-walled annular casting in the technical field of casting techniques. The casting and cooling system comprises annular cooling channels formed at the position, close to the thinnest wall, of the inner side of a thin-wall cavity of the casting at intervals, wherein each annular cooling channel is provided with an air inlet pipe and an air outlet pipe extending to the outside of a sand box, and the air inlet pipe is communicated with a compressed air source. A plurality of tiepieces connected with the cavity of the casting are arranged on the outer side of the thin-wall cavity of the casting in an adhered mode, and the length directions of the tiepieces are set in the axial direction of the annular thin wall. The cooling system is provided with the annular cooling channels formed in the inner side of the thin-wall cavity of the casting at intervals to replace chilling blocks, the thin-wall position is forcedly cooled, and the crack defect at the thin-wall position is overcome. The tiepieces are added on the outer side of the middle thin-wall position of the casting to decrease the tensile stress at the middle thin-wall position, heat at the middle thin-wall position is dissipated out through the tiepieces to enable the middle thin-wall position to quickly solidify due to the fact that the tiepieces solidify firstly, and accordingly shrinkage is prevented from being produced at the thin-wall position of the casting.

The invention provides a production method of wire rods for high-strength prestressed concrete steel rods. The production method includes: step 1, converter smelting, the carbon content of molten steel at the end of the converter is 0.06-0.15 wt%, the phosphorus content is 0.011-0.020 wt%, and the tapping temperature is 1630-1650°C; step 2, ladle furnace refining, refining is The bit temperature is 1504-1581°C, the refining off-position temperature is 1557-1605°C; Step 3, billet continuous casting, the superheat is set to 20-32°C, and the casting speed is set to 2-2.2m/min; Step 4, For high wire rolling, the billet heating time is more than 2 hours; the temperature setting of the heating section is: the temperature of the upper heating section is 1050-1200°C, the temperature of the lower heating section is 980-1180°C, and the heating section time is not less than 1 hour; the temperature of the upper soaking section is 1000 ~1200°C, soaking lower section temperature is 980~1180°C, soaking section time is not less than 1 hour; rolling start temperature is 960~1000°C; wire rod spinning temperature is 900~950°C. The wire rod for the high-strength prestressed concrete steel bar prepared by the method provided by the invention has stable and uniform quality and no crack defect.