136results about How to "Avoid Casting Defects" patented technology

The invention discloses a method for casting a large stamping cylinder casting, comprising the following steps of: 1) making a mould; 2) making a sand mould; and 3) pouring and moulding; when the sand mould is made, an upper core cover (19) is embedded in the center of a casting cavity (11) of an upper box, a lower core cover (17) with the same shape and size with the upper core cover (19) is embedded in a sand core (16) inside the casting cavity (11), and a mandril (18) made of iron is sheathed between the upper core cover (19) and the lower core cover (17). By adopting the structure, a gating system, arrangement of a dead head, laying of an cold iron, control of pouring temperature, control of chemical ingredients, control of spheroidization and inoculation and the like are all designed according to the characteristics of the casting, thus the casting defect that slag inclusion, an air hole and the like are produced can be overcome; and the probability that a shrinkage cavity and shrinkage porosity are caused can be reduced, thus the yield of casting finished products can be greatly improved.

The invention discloses a method for preparing a composite pipe by expanding a secondary pouring dual-metal pipe billet. The secondary pouring dual-metal pipe billet is manufactured by the following steps: by adopting an evaporative pattern casting process, pouring to obtain an inner-layer thin-walled high-alloy corrosion-resistant pipe billet, and by adopting a sand casting method, pouring to obtain an outer-layer carbon steel pipe billet, thereby obtaining the dual-metal pipe billet. The expanding process is characterized by comprising the following steps: by adopting the dual-metal pipe billet prepared by secondary pouring, performing three-roller hot-rolling expanding deformation, thereby obtaining the dual-metal composite pipe. According to fusion of the inner and outer layers of metals in the casting process and plastic deformation in the hot-rolling expanding process, the dual-metal composite pipe with good metallurgical bonding property can be obtained. According to the dual-metal composite pipe disclosed by the invention, the high-precision inner-layer metal surface is obtained by virtue of the evaporative pattern casting process, and the inner-layer metal thickness is controllable; and moreover, due to the three-roller hot-rolling expanding process, high-strength metallurgical bonding among the inner and outer layers of metals is realized, the inner-layer surface precision is high, the ellipticity is high, and the wall thickness precision is high.

The invention discloses a dual-compound wear-resisting hammer comprising a hammer handle and a hammer body; the hammer body is formed by compound casting of two kinds of metal liquids, and the hammer body is in casting connection with the solid hammer handle to form the hammer. The manufacturing method includes the following steps: step 1, manufacturing and casting a sand mold according to a structure of the hammer; step 2, processing the hammer handle with a low-alloy steel blank material, and preburying one end of the hammer handle into the casted sand mold of the hammer; step 3, selecting high-chromium cast iron and carbon steel, and carrying out quantitative pouring in sequence; and step 4, carrying out heat treatment. The dual-compound wear-resisting hammer not only can improve wear resistance of the hammer but also allows the hammer body and the hammer handle to be combined closely and not generate cracks, casting defects are overcome, the product yield is improved, the cleaning workload is reduced, and the quality and the service life of the hammer are improved substantially.

The invention relates to a production method of a grate bar material of a sintering machine. The production method mainly solves the problems that a high-alloy grate bar is complex in production process, relatively high in production cost, difficult in casting flaw control, non-uniform in performance and the like in the prior art. The technical scheme of the invention is as follows: the grate bar material of the sintering machine comprises the following chemical components in percentage by mass: 1-1.5% of C, 1.5-2.5% of Si, 1.2-2.2% of Al, 2.5-3% of Mn, 11-15% of Cr, 0.3-0.8% of Mo, 0.01-0.03% of Nb, 0.01-0.03% of Ti, 0.03-0.1% of Re, less than or equal to 0.06% of P, less than or equal to 0.06% of S, and the balance of Fe and inevitable impurity elements. A sand casting process of 'one pouring with more molds' is applied, so that the aluminum content and the casting flaws of a silicon grate bar are reduced, and the production cost is reduced. A heat treatment furnace provided with a flow guide circulating fan is applied to low-temperature uniform heat treatment on a cast so as to improve the performance uniformity of casts of the same batch. By adopting the production method disclosed by the invention, a grate bar product of the sintering machine, which is good in process stability, good in performance and relatively low in production cost, can be obtained.

The invention relates to a method for preparing a single-crystal copper bonding wire, which uses copper as a raw material. The method comprises the following steps: melting high purity copper of which the purity is higher than 99.995 percent by using a high-vacuum furnace, raising the temperature to between 1,100 and 1,180 DEG C, refining the copper for 60 to 120 minutes, and adopting high purity argon for protection in the whole melting process; broaching single-crystal copper rods of phi 4 to phi 8 mm in a directional solidification mode, and then coldworking the single-crystal copper rods to between phi 0.95 and phi 1.102 mm with the broaching working rate of 15 to 25 percent for each gate; broaching the single-crystal copper rods to between 0.020 and 0.05 mm with 47 to 70 gates and the working rate of 7.59 to 17.82 percent for each gate; and carrying out sonicleaning on the surface of the single-crystal copper bonding wire when the wiredrawing temperature is between 35 and 45 DEG C, carrying out heat treatment on the cleaned single-crystal copper bonding wire, and using H2+Ar2 for protection with the temperature of between 410 and 425 DEG C, the time of between 0.7 and 2.0s and the annealing rewinding tension of between 0.6 and 2.8g.

The invention provides a low-power radial welding bogie comprising two wheel sets, a three-piece side welding beam and a crossbeam. Two ends of the side beam are connected with the wheel sets through primary rubber-metal pads and bearing saddles respectively. The wheel sets are connected with a wheel set connecting device through the bearing saddles. A crossbeam assembly is connected with the side beam through two secondary suspension systems. A foundation brake gear is suspended on the crossbeam assembly or the side beam. The secondary suspension systems have multiple structural styles, and the wheel sets are of variable- gauge structures. Compared with conventional freight car bogies, the low-power radial welding bogie has the advantages that the bogie is good in uniform load performance; defects of cast structure swing bolsters and side frame casting are avoided; wheeltrack acting force is reduced, and wear parts of the suspension systems are reduced; the variable-gauge wheel sets meet requirements on variable-gauge performance of the bogie; high-speed operation stability of the bogie is improved, and rim wear generated when the bogie passes curves is reduced; the bogie can meet the requirements on maximum axle load of 30t and highest running speed of 200km / h.

The invention provides a method for preparing an aluminum matrix composite through high pressure solidification after semi-solid mechanical stirring and relates to a method for preparing the aluminum matrix composite. The method provided by invention aims to solve the problems of the stirring casting method of needing to evenly distribute reinforcements in the matrix metal, and needing to avoid harmful reaction between the reinforcements and the metal at high temperatures, and reducing the casting shortcomings generated in the solidification process. The method comprises the following steps of: 1, preparing SiC slurry; 2, preparing reinforcement particles; 3, preparing alumium alloy melt; 4, preparing compound slurry; 5, increasing the temperature and stirring; and 6, obtaining the alumium matrix composite. The method provided by the invention avoids harmful reaction between the reinforcements and the matrix metal and the formation of casting shortcomings, and also avoids harmful reaction between the reinforcements and the matrix metal at a high temperature in full liquid state. The method is used for preparing the alumium matrix composite.

The invention discloses a multipurpose semicontinuous vacuum induction casting furnace, comprising a melting chamber, wherein a continuous feeding device and an alloy feeding port are arranged at the upper part of the melting chamber; an induction heating crucible device is arranged in the melting chamber; a liquid outlet is arranged in the induction heating crucible device; chutes are arranged at the liquid outlet side of the induction heating crucible device; casting chambers are arranged below the chutes; an ingot mould is arranged in the right casting chamber; an ingot mould vehicle is arranged below the ingot mould; melted materials are fed into the induction heating crucible device by the continuous feeding device; after metal is melted, the right chute is moved to the liquid outlet of the induction heating crucible device; the induction heating crucible device is inclined; molten metal enters the ingot mould of the right casting chamber by the right chute to cast an ingot blank; after the ingot blank is cooled, the ingot mould is moved out by the ingot mould vehicle; when another purpose of drop-down ingot casting or casting is realized, the left chute is moved to make the molten metal enter the left casting chamber to carry out casting or drop-down ingot casting. The multipurpose semicontinuous vacuum induction casting furnace has the characteristics that multi-species continuous alternative operation is realized, energy is saved, the efficiency is high, and the metal quality is greatly improved.

The invention discloses a preparation method for a high-strength wear-resistant alloy Cu-15Ni-8Sn. The process comprises the following steps: adding electrolytic copper and nickel; pouring the electrolytic copper and nickel in an intermediate-frequency coreless induction furnace; adding charcoal; charging nitrogen gas with one barometric pressure; melting; melting for 30-65 minutes at 1300-1350 DEG C; adding tin and melting at 1250-1300 DEG C; adding a refiner and a deoxidizer; stirring; adding a grain refiner; adding a modifier; slagging off; carrying out inspection before melting; carrying out electromagnetic casting after ingredients are qualified; cutting a head and a tail; scalping; carrying out ingredient inspection after melting; carrying out organization structure analysis; and carrying out performance detection. A Cu-15Ni-8SnC72900 alloy melt and cast by virtue of the intermediate-frequency coreless induction furnace, which is obtained by the preparation method disclosed by the invention, is low in production cost; and the developed products are high in quality. The developed products can be applied to national defense and military industry, ocean engineering and high-end preparation manufacturing industry; and the increasingly urgent needs of the national defense and military industry, ocean engineering and high-end preparation manufacturing industry on high-performance copper alloy materials are met.

The invention discloses a single crystal copper bonding lead and a preparation method thereof, relating to the field of production of microelectronic materials. The production technology integrates a metal material preparation process, a heat treatment process and a diamond die process, ensures the production consistency and reliability and realizes the large-scale production. The adopted production process comprises the steps of providing die repair and gas protection equipment, smelting, wiredrawing, cleaning, and compounding, packaging and testing a finished product. The single crystal copper bonding lead has the beneficial effects that as a signal crystal copper material has a compact solidification structure, lateral crystal boundaries are eliminated, the casting defects of shrinkage cavities, pores and the like are avoided, the plastic working performance, the mechanical performance, the electric performance and the like of the signal crystal copper material are obviously higher than those of the conventional oxygen-free copper, the defects of more end breakage, low quality and low productivity in the wiredrawing process of the conventional copper wire are overcome, and an electronic packaging bonding wire with the wire diameter reaching 0.015m, high strength, high elongation and stable performance can be prepared.

The invention relates to a metal casting method which comprises the following steps: firstly, spraying sizing agent and investment precoat are prepared, an air inlet of a spraying gun is connected with a high-temperature wind pipe, and a sizing agent inlet of the spraying gun is inserted into the prepared spraying sizing agent; a casting mould is prewetted according to a conventional process; the high-pressure wind pipe is opened, a spout of the spraying gun is aligned with the surface of the casting mould to spray a layer of sizing agent, and a sizing agent layer is formed on the surface of the casting mould; the casting mould with the surface sprayed with the sizing agent is put into the prepared investment precoat and is then sprayed, rotatably coated and sand-filled according to the conventional process. The metal casting method has simple process, greatly improves the coating property of the investment precoat of the casting mould, better improves the phenomenon that bubbles appear on the surface of the casting mould, increases the size precision, the contour sharpness and the surface finish quality of the casting, solves the common casting defects of iron blains, iron pricks, bumps, and the like, lowers the production cost, and shortens the production period.

The invention relates to the field of casting auxiliaries materials, in particular to a manufacturing method of an oxidized graphene modified 3D printing resin. The graphene modified 3D printing resin is prepared from, 7-13% of phenol, 1.5-2.5% of formic acid, 45-65% of furfuryl alcohol, 13-19% of formaldehyde, 7-13% of resorcinol, 3-7% of oxidized graphene, 0.5-1.5% of coupling agent and 0.5-1.5% of ethylene urea. Aimed at the problem in the prior art that a traditional resin for steel casting exits deficiences in 3D foundry sand printing, the oxidized graphene is creatively introduced, and thus the problem of sand burning in the steel casting is fundamentally solved; in addition, the oxidized graphene modified 3D printing resin can be used for conducting moulding on a sand mould with high heat resistance and high rigidity, can be used in a more complicated and thinner high-end casting, is stable in chemical properties, applicable to 3D printing technologies, high in strength of the foundry sand, simple and convenient to operate, and excellent in anti-sand burning performance.

The invention relates to a novel aluminum alloy; the content of Si in the aluminum alloy is adjusted, based on the aluminum alloy A356.2; the chemical components thereof are as follows: larger than 7.5 to 8.2 percent of Si, 0.28 to 0.45 percent of Mg, 0.08 to 0.20 percent of Ti, not larger than 0.12 percent of Fe, not larger than 0.01 percent of Cu, not larger than 0.01 percent of Zn, not larger than 0.05 percent of Mn, not larger than 0.05 percent of Zr, not larger than 0.01 percent of Ni, not larger than 0.01 percent of Sn, not larger than 0.10 percent of microelements and the rest is Al. In the invention, as the content of Si in the aluminum alloy is properly added, the novel aluminum alloy can optimize the matching between the anti-tension intensity and the extending rate of the aluminum alloy, increase the anti-impact performance of the product and simultaneously improve the casting fluidity of the aluminum alloy and effectively reduce the casting defect; therefore, the novel aluminum alloy has the characteristics of optimizing the matching between the anti-tension intensity and the extending rate of the aluminum alloy, increasing the anti-impact performance of the product, improving the casting fluidity, avoiding casting defect, improving the product quality, and the like.

The invention provides a surface treatment technique for an aluminum alloy die casting. The technique comprises the following steps that 1, the aluminum alloy die casting is provided; 2, surface pretreatment is conducted on the aluminum alloy die casting; 3, cold spraying is conducted on the aluminum alloy die casting; and 4, alkaline electrolysis polishing treatment is conducted on the aluminum alloy die casting. By the adoption of the surface treatment technique for the aluminum alloy die casting, the defects of the surface of the aluminum alloy die casting are overcome, and an aluminum alloy die-cast product high in surface quality is obtained.

The invention relates to a method for the sleeve joint of liquid pipelines and a device thereof. The invention belongs to the technical field of hydraulic systems. The liquid pipeline sleeve joint method is characterized in that a main tube has holes, branch tubes or valves are in sleeve joint with the main tube, and the branch tubes or valves are hermetically assembled with the corresponding holes of the main tube by sleeve joint fasteners to realize the communicated with between the branch tubes or valves and the main tube. The liquid pipeline sleeve joint device is characterized in that the main tube is provided with holes, the branch tubes or valves are connected with the main tube by the sleeve joint fasteners, and the sleeve joint fasteners are sleeved around the main tube and tightly connected with the branch tubes or valves, so that the branch tubes or valves are the corresponding holes of the main tube. The invention has the advantages of simple structure, easy fabrication and installation, high mechanical strength, easy construction, high rate of finished products, and low system cost.

The invention discloses a ship-based multifunctional photoelectric monitoring system. The ship-based multifunctional photoelectric monitoring system comprises a system front-end and a system back-end;the system front-end comprises a two-axis stabilized platform, a photoelectric payload, a servo control unit, a signal processing unit and an image processing unit; the system back-end comprises a display controller and a handspike console; the photoelectric payload comprises an infrared thermal infrared imager, a high-definition visible light camera, a laser illuminator and a laser rangefinder;the image processing unit is used for receiving image information of the infrared thermal infrared imager and the high-definition visible light, and locking and tracking a target; the servo control unit controls an electric motor to drive a turntable to rotate, thereby realizing functions such as stable control and tracking control of the turntable; the signal processing unit is used among the photoelectric payload, the image processing unit and the servo control unit and is used for building communication connection between the system front-end and the system back-end. The ship-based multifunctional photoelectric monitoring system has the characteristics of light weight, complete functions and short production and manufacturing cycle.

The invention relates to a high texture magnesium alloy surface treatment method and a product thereof. The method comprises: (1) die casting forming of a magnesium alloy work-piece; (2) a surface pre-treatment; (3) a formation treatment; (4) cold spray coating; and (5) an electrophoresis coating treatment. The product is the product produced through treatments by using the method. According to the present invention, the product with the high texture appearance can be produced on the magnesium alloy die casting surface, the method has characteristics of environmental protection process, simple process and substantial magnesium alloy die casting finished product yield increase, and is suitable for large scale industrial application, and the treated product has characteristics of good corrosion resistance, compactness, beautiful appearance, changeable color, metal effect and metal color penetration effect.

The invention provides a phosphorization surface treatment technique for an aluminum alloy die casting. The technique comprises the following steps that 1, the aluminum alloy die casting is provided; 2, surface pretreatment is conducted on the aluminum alloy die casting; 3, cold spraying is conducted on the aluminum alloy die casting; and 4, phosphorization treatment is conducted on the aluminum alloy die casting. By the adoption of the surface treatment technique for the aluminum alloy die casting, the defects of the surface of the aluminum alloy die casting are overcome, and an aluminum alloy die-cast product high in surface quality is obtained.

Disclosed is an internal top-mounting type super-high pressure super-low temperature hard sealing ball valve, which is mainly composed of a valve body (1), a valve cover (24), a ball body with a handle (3), a valve seat (13), a rear valve seat (10), a valve rod bearing seat (16) and the like. The ball body with a handle (3) placed in the valve body (1) penetrates through the center of the valve cover (24), and the ball body with a handle (3) is enabled to rotate 90 degrees by an external force to realize the opening and the closing of pipes. The sphere sealing is realized by that two sides of the ball body with a handle (3) hold the rear valve seat (10) and the valve seat (13), and a valve seat spring (12) elastically pushes and presses the ball body with a handle (3). The sealing of a valve rod employs a unique three-ply sealing structure of a self-sealing preloading device, which can guarantee sealing under low pressure, and under the action of high pressure, medium pressure action realizes self-sealing for a bearing ring (17), thereby avoiding that filling material sealing needs the high-strength pressure, and the torque becomes extremely large when the valve rod is opened.

The invention belongs to the technical field of bonding gold wire processing, in particular to a 4N bonding gold wire capable of being processed to phi 6 micrometers through wire drawing and a preparation method of the 4N bonding gold wire. The 4N bonding gold wire comprises gold and an alloy additive. The alloy additive is formed by copper, vanadium, magnesium, palladium, silver, nickel, bismuth,beryllium, cerium, zinc, yttrium, calcium, gadolinium, aluminum and lead. According to the prepared bonding gold wire, the alloy additive of the specific components and content is added, the drawingstrength of the gold wire can be improved through the alloy additive, and the radian of the bonding gold wire can be reduced; the prepared bonding gold wire has the good low and long radian through adding of the additive and the reasonable proportion while guaranteeing high strength; the prepared gold wire has good drawing strength, heat conductivity, resistance and low and long arc length; and meanwhile, axial long crystals are formed after a single-crystal continuous casting method is adopted for casting, high purity and a continuous columnar crystal structure are achieved, a transverse crystal boundary is eliminated, casting defects are avoided, and the prepared gold wire can be processed to 6 micrometers.

The invention relates to a production method of a 2507 stainless steel pump casting. The method includes (1) die designing and manufacturing, (2) moulding and core manufacturing, (3) paint brushing, (4) sand mould and sand core drying, (5) mould assembling, (6) smelting, (7) pouring, (8) mould disassembling and sand removing, (9) gate and riser removing, (10) repair welding, and (11) polishing andshot blasting. Through a reasonable casting process design, casting defects including air holes, oxide slag inclusion and cracks are prevented, the repair rate and the rejection rate of casting are reduced, product quality is ensured, subsequent repair welding is greatly reduced, and the production cost of the casting is reduced.

The invention discloses a nucleating agent containing rare earth. The nucleating agent is composed of the following components of the rare earth, lead, antimony, silicon, calcium, magnesium, aluminum and the balance iron and inevitable microelements. Application of the nucleating agent to spheroidal graphite cast iron smelting comprises three times of nucleation. Compared with the prior art, the nucleating agent has the following beneficial effects that the magnesium is added and combined with rare earth elements, so that alloy crystals have the more stable phase in a reaction and cannot be decomposed when coming across moisture or water, and the stability of the alloy crystals do not become poor along with the time; meanwhile, through multiple times of nucleation, mobility of molten iron can be improved, and the deoxidization effect of the molten iron is improved; and meanwhile, the remarkable effect on spherification and ferritiszation of spheroidal graphite is achieved and casting defects caused by much slag and cavity shrinkage can be effectively overcome.

The invention discloses a production technology for a casting zinc alloy water faucet. The technology comprises the following steps: A, forming a zinc alloy water faucet body by using gravity casting;B, performing shot-blasting sand-blasting pretreatment on the zinc alloy water faucet body; C, performing cavity wall sealing treatment on the zinc alloy water faucet body; and D, performing surfaceplating-coating treatment on the zinc alloy water faucet body, wherein a technology of the cavity wall sealing treatment in the step C comprises the following steps: C1) mixing powder: enabling dry organosilicon epoxy resin powder to be mixed with dry air, after adequately mixing, sending to a powder spray gun; C2) spraying powder: enabling a powder spray pipe of the powder spray gun to be slowlyinserted in a cavity of a casting body, beginning spraying the powder, enabling the powder spray pipe to be reversely and slowly withdrawn along the cavity of the casting body, after the powder spraypipe is completely withdrawn, stopping spraying the powder; and C3) roasting: placing the sprayed coasting body in an oven for roasting, after roasting, cooling and taking out the casting body.

The invention relates to a mechanical casting process, relates to a casting method of a high-quality ship medium-speed series diesel front end box body, and is characterized in that the casting method comprises the following specific steps: (1) molding and preparing a core; (2) smelting original molten iron: adopting 65% of pig iron, 35% of scrap steel, an alloy and a recarburizing agent as raw materials, overheating for 5 min at a melting temperature of above 1500 DEG C, carrying out pure purification of the molten iron, and controlling the original molten iron chemical composition to have the following content by the weight percentage: 3.0-3.1% of C, 1.1-1.2% of Si, 0.9-1.1% of Mn, not more than 0.10% of P, not more than 0.10% of S, 0.6-0.8% of Cu, 0.2-0.3% of Cr, and the balance being Fe; (3) carrying out first inoculation treatment; (4) carrying out secondary inoculation; and (5) pouring: carrying out pouring and the secondary inoculation simultaneously with the pouring speed of 35-40 kg / s, controlling the pouring time of 90-100 s, adding the pouring time of not less than 3 min after iron appears at a riser, and designing a pouring system as a double-layer ladder type. The casting method solves the problems that a conventional ship diesel front end box body casting method has many product defects and low finished product rate, and is especially suitable for the casting of the medium-speed series diesel front end box body.

The invention discloses a preparation method for a bimetal metallurgy composite pipe of a three-layer structure. The method includes the steps that firstly, a thin-walled high alloy anti-corrosion pipe blank on the inner layer and a thin-walled high alloy anti-corrosion pipe blank on the outer layer are prepared through pouring according to a lost foam casting method; then, an interlayer carbon steel pipe blank is prepared through pouring and EPS modeling with the high alloy pipe blanks on the inner layer and the outer layer as mold cores, and a stainless steel / carbon steel / stainless steel bimetal composite pipe blank of a three-layer structure is obtained; and the bimetal composite pipe of the three-layer structure is manufactured by conducting three-roller hot rolling expanding deformation on the obtained bimetal pipe blank of the three-layer structure. The high-accuracy metal surfaces on the inner layer and the outer layer are obtained according to the lost foam casting method, and the metal thickness of the inner layer and the outer layer can be controlled. The resistance to three-roller hot rolling expanding deformation is small. The three layers of metal are combined through high-strength metallurgy. The surfaces on the inner layer and the outer layer are high in accuracy, good in ovality and high in wall thickness accuracy.

The invention discloses a casting method of a large-area thin-wall part. The casting method includes the following steps of S1, preparing of silica sol coating; S2, slurry pasting, wherein a wax moldwith the shape the same as that of the large-area thin-wall part is soaked in the silica sol coating, and the surface of the wax mold is wet by the silica sol coating; S3, sand hanging, wherein aftersand grains are evenly attached to the coating on the surface of the wax mold,drying is carried out; S4, repeating of S2 and S3, wherein multiple times of slurry pasting and sand hanging are carried out, and a multi-layer mold shell is prepared; S5, dewaxing, wherein the mold shell is obtained; S6, roasting of the mold shell; and S7, casting and then natural cooling, wherein the large-area thin-wall part is obtained after mold release. When the large-area thin-wall part is cast, casting process parameters are improved, when the large-area thin-wall part is cast through precision casting, a heat mould gravity casting manner wide in application range is used, string breaking generated in the casting process is avoided, the casting defects of shrinkage porosity and cavities can be overcome, the percent of pass of casting products is increased, and the casting cost of the large-area thin-wall part is reduced.

The invention discloses a main oil duct sand core of a diesel engine frame and a manufacturing method thereof. The main oil duct sand core comprises a main core body and a main oil duct sand core bodyarranged on the main core body; the main oil duct sand core body is divided into a plurality of oil duct sand core subsections with the center of each gear of crank as the parting surface according to the number of cylinder bodies of the diesel engine frame; each oil duct sand core subsection is composed of a core rod and a sand body wrapping the core rod; positioning core heads are arranged at one ends of the oil duct sand core subsections, and positioning core grooves are formed in the other ends of the oil duct sand core subsections; the positioning core heads of the front oil duct sand core subsections are inlaid in the positioning core grooves of the rear oil duct sand core subsections for connection; and the main oil duct sand core further comprises two side core heads arranged at the front and rear ends of the multiple connected oil duct sand core subsections. Through the sectioning casting technology of the main oil duct sand core, the perpendicularity and concentricity of a main oil duct are guaranteed, and the casting defect of leaking in pressure testing is overcome thoroughly.

The invention discloses a calendaring roller shell and a manufacturing method of the calendaring roller shell. The calendaring roller shell is made of forged steel. The manufacturing method of the calendaring roller shell comprises the steps of roller blank preparation, thermal refining, surface quenching treatment, tempering treatment and final machining treatment. A line-frequency induction quenching method is adopted by surface quenching treatment. The quenching temperature is 890 DEG C-910 DEG C, the heating width of a line-frequency induction ring is 80mm-100mm, and the walking speed of the line-frequency induction ring is 0.8mm / s-1.2mm / s. According to the calendaring roller shell, cast iron is replaced by the forged steel and a special surface quenching technology is combined, so that the hardness of the surface of the finally machined calendaring roller shell reaches 82 HSD-88HSD, the uniformity of hardness is equal to or smaller than 3HSD, the depth of a surface quenching layer reaches 15mm-20mm, and the service life reaches over 20 years.

The invention discloses a steel cap for a disc-shaped suspension insulator string element and a machining method of the steel cap. The machining method comprises the steps of (1) blank preparing, wherein Q235 carbon steel rods are cut into blank materials; (2) blank heating, wherein the blank materials are heated to 1000 DEG C-1100 DEG C; (3) die forging, wherein the heated blank materials are subjected to pre-forging and final forging on a forging machine, and a steel cap blank piece is formed; (4) trimming, wherein the steel cap blank piece is subjected to side cutting and hole punching trimming; (5) machining, wherein the trimmed steel cap blank piece is subjected to machining; (6) heat processing, wherein the steel cap blank piece is subjected to annealing treatment; (7) abrasive blasting, wherein the steel cap blank piece after heat processing is subjected to abrasive blasting, a surface oxidation layer is removed, and hot galvanizing attaching strength is enhanced; and (8) hot-dip galvanizing, wherein hot-dip galvanizing is carried out according to the standard JB / T8177. The steel cap for the disc-shaped suspension insulator string element is machined and manufactured through the method.