36results about How to "Solve shrinkage defects" patented technology

The invention discloses high-silicon-molybdenum vermicular graphite cast iron. The high-silicon-molybdenum vermicular graphite cast iron comprises, by mass percent, 3.1%-3.4% of C, 4.3%-4.8% of Si, 0-0.3% of Mn, 0-0.07% of P, 0-0.02% of S, 0.5% to 0.75% of Mo, 0.025%-0.045% of Mg, 0.006%-0.01% of Ca, 0.04%-0.06% of Al and the balance Fe and inevitable microelements. A production method of the high-silicon-molybdenum vermicular graphite cast iron is further disclosed. Prepared materials are put into an electric furnace to be smelted. During ladle casting, a vermiculizer and a nucleating agent are added, and the performance of the cast iron can be improved. Carbide generated inside the cast iron is stable, the heat-resisting performance of the cast can be effectively improved, the creep ratio of the large-thick portion of the cast is improved to above 70%, the tensile strength is improved to 640 Mpa, the yield strength is improved to 570 Mpa, and the performance of the obtained casting is very excellent.

The invention provides a novel high-strength casting mould structure for a car brake disc. The novel casting mould structure is formed by compounding two outer moulds and a sand core, wherein the sand core is located in the outer moulds. According to the novel casting mould structure, the strength, the toughness, the weather resistance and the processability of a rear brake disc for a car are improved. A micro-alloy vanishing ring is additionally arranged at an R angle part which easily generates inner looseness in the casting mould so as to improve the strength and the toughness of a casting. The casting is commonly molded by the sand moulds and the sand core; a casting system is arranged in the sand core; a ceramic filtering sheet, an annular liquid inlet sheet, a chilling block and a dead head of the casting system are arranged reasonably so that the defects of the casting are improved and the product quality is improved.

The invention belongs to the field of casting and mainly relates to a casting method capable of preventing defects of an air cylinder casting pipe orifice. When the pipe orifice part is casted in theprior art, one loop of cold iron is adopted, and the casting defects such as shrinkage porosity and slag inclusion exist among the cold iron through RT ray detection; in consideration of the above problem, the invention provides a casting method capable of preventing casting defects for an air cylinder casting pipe orifice part. The casting method comprises: a casting process scheme of placing theair cylinder casting with the upward combined surface and the downward pipe orifice is selected, a crossed riser neck is arranged at the radial part of the air cylinder casting pipe orifice, a blindriser is arranged at the middle position of the crossed riser neck, and partitioned cold iron is arranged on the end face part of a crossed riser neck feeding superposed area of the air cylinder casting pipe orifice, so that the casting defects such as shrinkage porosity, slag inclusion and crack on the air cylinder casting pipe orifice part are effectively avoided, the quality of the air cylindercasting is improved, and the standard requirement for the RT ray detection first level of the air cylinder casting pipe orifice part is met.

The invention discloses a control method for increasing the number of graphite nodules by solid solution strengthening ferrite nodular cast iron with a thick and large cross section, which comprises the following steps: selecting materials: 50-70 percent of pig iron and 30-50 percent of scrap steel; smelting: adding the materials into an electric furnace for smelting, wherein the tapping temperature of the molten iron is 1420-1450 DEG C; spheroidizing: adding a spheroidizing agent, adding a covering agent on the spheroidizing agent, and then spheroidizing, wherein the spheroidizing temperatureis 1420-1450 DEG C; inoculating: adding a silicon-aluminum-calcium-barium type inoculant during a primary inoculation, and respectively adding the inoculant on the surface of the covering agent and the other side of a ladle dam before tapping, wherein the distribution proportion is 50 percent; adding a trace amount of alloy Sb along with the flow of the molten iron during casting, wherein the adding amount of the alloy Sb is 0.003-0.005% of the total amount of the molten iron, molding, casting and cooling: ensuring that the casting opening temperature is controlled to be <= 300 DEG C, and thecasting is obtained by air cooling after the casting is opened. The control method has the advantages of obtaining higher number of the graphite nodules, ensuring a metallographic structure and goodconsistency of performance indexes, thereby improving the quality of the castings and prolonging the service life.

The invention discloses a casting method for protecting a thin-wall casting from local isolated hot spot shrinkage. The casting method comprises the steps of manufacturing a sand core; manufacturing a corresponding densener die; utilizing the densener die to obtain an aluminum alloy densener; enabling the aluminum alloy densener to adhere to a corresponding isolated hot spot part of the sand core; manufacturing molten aluminum; placing the sand core in a cavity of a thin-wall casting die; pouring the molten aluminum into the cavity of the thin-wall casting die, and forming a casting by cooling; and performing operation of removing the sand core and a casting head to obtain the finished product thin-wall casting. The hot spot part is subject to chilling through the densener, so that the hot spot first is solidified, and the shortcoming of shrinkage is overcome.

The invention discloses an insulating riser, comprising a hollow riser body. The hollow riser body comprises an insulating layer and a plurality of heating sheets, the plurality of heating sheets are peripherally bonded to the inner wall of the insulating layer, the heating sheets are tightly attached to one another, the outer side of the heating sheets mates with the inner side of the insulating layer, and the heating sheets are connected with the insulating layer through a locking device located outside the insulating layer; the heating sheets are made from, according to parts by weight: 30-50 parts of hollow microspheres, 10-20 parts of aluminum powder, 5-15 parts of ferric oxide, 20-40 parts of magnesium powder, 40-60 parts of charcoal powder, 5-15 parts of potassium permanganate, and a suitable amount of bonding agent and water, wherein the bonding agent is sodium silicate. The invention also discloses a manufacture method of the insulating riser, overcoming looseness and shrinkage defects of light alloy sand castings, improving compactness of castings, saving energy and reducing consumption, and reducing production cost.

The invention discloses a casting method of a body casting of a centrifugal air compressor. The method comprises the following steps of: sand mulling, moulding, core making, mould assembly, furnace burden melting, iron discharge incubation, pouring, cooling, box opening, casting cleaning and product quality inspection. In the invention, multiple sand cores are designed to form a whole casting, and the pouring of the whole casting is finished by adopting a mode of dispersing the pouring with multiple sheet-type ingates. The mechanical performance of the casting meets that the tensile strength is greater than or equal to 250Mpa and the body hardness is 170-230HBS. The product does not have any internal casting defect.

The invention discloses a method for improving the internal quality of a high manganese steel frog and lowering the production cost, and relates to the procedures of model forming, modeling and removal of risers. Innovative special-shaped risers, easy-to-cut pieces, frog structures, repairing and attaching forms and riser removal methods are put forward, and the traditional process of removing risers through a hot-cutting method, namely the method of conducting melting through burning, and high-temperature heat release of sharp gas (acetylene) is omitted, so that the energy is saved, and environmental pollution is avoided; and moreover, the situation that the high manganese steel frog has high cross-section appearance quality after being hammered, then a high stress area is formed due to local uneven heating of the hot risers to the frog rail wall, and then hot cracks are generated in the rail wall, and cause scrapping due to centralized release of heat in a finally-solidified organization part of a casting can be essentially avoided. At the same time, the repairing and attaching of the riser feeding channel is added, the modulus of the feeding channel is increased, the feeding effect of the risers is improved by more than 500%, the internal density of the high manganese steel frog is increased, the generation of shrinkage porosity defects is avoided, and the quality bottleneckof the traditional casting process is overcome. According to the method, the feeding channel can also be recycled for repeat use, so that the cost is lowered.

The invention relates to a multi-rubber rotary body casting. The multi-rubber rotary body casting comprises a base and a matrix. The base is in a cube shape. The matrix is in a two-step columnar shape. The second step of the matrix is connected with one end face of the base. Four oil outlets are evenly arranged on the second step of the matrix by a circle, and the four oil outlets are distributedin a staggered manner in the axial direction of the matrix. Four oil inlets are evenly arranged on the other end face of the base. The oil inlets and the oil outlets are in one-to-one correspondence and are connected through runner holes formed in the rotary body casting. Design is reasonable, the structure is simple, the defect of shrinkage porosity of the casting is overcome, and meanwhile the size of each runner hole in the rotary body casting can be guaranteed.

The invention relates to a flow meter housing casting piece, in particular to a housing casting piece of a flow meter. The flow meter housing casting piece comprises a straight pipe, and is characterized in that radial bosses are formed at the both ends of the straight pipe; a radial hole for mounting a sensor is reserved in the middle of the straight pipe; a radial embossment is processed on one side in the middle of the straight pipe; and the radial hole is cast on the radial embossment. The flow meter housing casting piece is better in quality.

The invention relates to the technical field of engineering machinery, in particular to a chain wheel seat casting system. The system comprises a pouring cup, a straight pouring gate and a transverse pouring gate which are communicated, a blind riser is arranged at the end of the transverse pouring gate and communicated with an inner pouring gate in a 90-degree angle, the inner pouring gate is communicated with a casting cavity of a chain wheel seat, and the joint of the inner pouring gate and the casting cavity is a center hole of the chain wheel seat. The inner pouring gate is in contact with the casting cavity at the center hole of the chain wheel seat, so that the inner pouring gate can be connected with the structure of the chain wheel seat in a 360-degree range, molten iron is ensured to be quickly injected into an upper cavity and a lower cavity of the casting cavity, sequential solidification is realized, the phenomenon of shrinkage porosity is avoided, and meanwhile, the separation part of the inner pouring gate and the cast chain wheel seat is positioned at the center hole, so that a casting head formed through separation can be removed in a drilling manner or a trepanning drilling manner, the trace of the casting head formed on the chain wheel seat is avoided, the quality of the chain wheel seat is improved, meanwhile, damage caused by manual polishing of the casting head is avoided, and the machining efficiency is improved.