32results about How to "Reduces shrinkage tendency" patented technology

The invention relates to a single cylinder diesel engine body and particularly relates to a vermicular graphite cast iron single cylinder diesel engine body with high vermicular graphite rate. The single cylinder diesel engine body comprises the following chemical components in percentage by mass: 3.5-3.8% of C, 2.1-2.6% of Si, 0.5-0.8% of Mn, less than 0.08% of P, less than 0.03% of S and the balance of iron and inevitable impurities. The single cylinder diesel engine body provided by the invention has the characteristics of less inclination of shrinkage cavity and shrinkage porosity and long service life. The invention further provides a preparation method of the single cylinder diesel engine body, which is reasonable in process.

The invention discloses a nodular cast iron manhole cover casting method for preventing cold shut defects. Molten iron component selection is controlled, microelements exceeding general standards arenot allowed, reasonable nodulizing agents and nucleating agents are added, lanthanum can eliminate graphite deterioration and graphite floatation, the tendency of blooming graphite aggregation is decreased, the number of graphite nodules can be increased, nodulizing rate is increased, shrinkage porosity tendency is decreased, high-quality nodular cast iron liquid is provided, and the cold shut defects of a formed cast iron manhole cover are decreased. By strictly controlling casting temperature and casting modes, the probability of casting defects such as sand burning, shrinkage and deformation is reduced, and each casting mould is uniformly filled with molten iron. The cold shut defects are prevented by the aid of component control, casting temperature and mode control and the like in thecasting process, the nodular cast iron manhole cover is excellent in quality and mechanical property and worthy of popularization, and the process is conveniently controlled.

The invention discloses a sampling device for accurate quantification of carbon content in spheroidal graphite cast iron and additionally discloses a sampling method using the sampling device for the accurate quantification of the carbon content in the spheroidal graphite cast iron. According to the technical scheme of the invention, the sampling device for the accurate quantification of the carbon content in the spheroidal graphite cast iron comprises a sampling base and a sampling handle. A sampling cavity is arranged on the sampling base. The wall surface of the sampling cavity is a spherical crown surface. The sampling handle comprises an operating handle and a sampling ball. The sampling ball is connected with the bottom end part of the operating handle. The diameter of the sampling ball is the same as the diameter of the sampling cavity. By using the device, the precision of carbon content detection is improved, the operation is convenient and the shrinkage trend of castings is reduced.

The invention discloses a large cylindrical shell aluminum alloy casting low-pressure casting and shrinking control device. The large cylindrical shell aluminum alloy casting low-pressure casting and shrinking control device comprises a sand box, a casting, a pouring system, vibrators and vibration guide rods. The vibration guide rods are connected between a vertical cylinder pouring channel of the pouring system and the sand box. The vibrators are arranged on the outer surface of the sand box. The vibration direction of the vibrators is in line with the direction of the guide rods and tightly connected with the guide rods. The vibrators are adopted for providing a vibration source, the vibration guide rods are used for vibrating and guiding the casting and vibration is generated in the casting. Vibration transmitted by the guide rods is used for eliminating shrinking formed in the casting in the solidifying process. The vibrators vibrate in the normal direction of the outer surface of the cylindrical sand box and the guide rods are arranged in the normal direction of the outer surface of the sand box and coincide with the vibration direction of the vibrators. Meanwhile, the direction of the guide rods is parallel to the normal direction of the outer surface of the casting. According to the large cylindrical shell aluminum alloy casting low-pressure and shrinking control device, the density of the casting is reduced, the tendency to shrinking of the casting is relieved and the qualification rate of the casting is greatly improved.

A process method for a thin plate NdFeB ingot characterizes in purifying the NaFeB melt and controlling the cooling speed of the ingot after casting, in which, the purification is to add Ca and its alloy and let the melt pass through a pouring cup with a mini-hole foam ceramic filter plate to enter into the mold and the control of the cooling speed is realized by using a flat mold made of Cu and its alloy attached by two water cooling cover dies at its both sides to greatly reduce impurities in the ingot and refine the grains so as to improve the structure and increase the rate of finished products.

The invention discloses an engine piston blank which comprises a skirt portion and a head portion. A dead head is arranged on the top surface of the head portion. The top surface of the head portion is provided with an annular groove which surrounds the dead head and is recessed downwards. The bottom surface of the annular groove is close to the bottom surface of the combustion chamber of a pistonfinished product. The inner side wall of the annular groove is the outer peripheral side face of the dead head. The outer side wall of the annular groove serves as a machining positioning surface andis positioned close to the throat of the piston finished product. Machining allowance layers are arranged between the machining positioning surface and the throat, and also between the bottom surfaceof the annular groove and the bottom surface of the combustion chamber. The general shape of the combustion chamber and the throat is directly cast, and the metallographic structure of a local area is refined. The method is easy to realize and the effect is better. Meanwhile, the cost is lower, and the fatigue strength is improved. The purpose of greatly reducing the cracking failure risk of thethroat is achieved. A formed blank surface is used as a machining positioning surface for subsequent machining, and then the follow-up mechanical machining is carried out. The piston quality is improved. The invention further discloses a machining method of the engine piston blank.

The invention discloses a nickel-free low-silver-content Tibetan silver alloy with excellent die-casting performance and a process thereof. The alloy is prepared from the following components of, in percentage by weight, 0.4w%-0.5w% of B, 1.0w%-1.2w% of Ca, 2.0w%-3.5w% of Al, 1.0w%-1.8w% of Si, 0.2w%-0.3w% of Os, 1.0w%-1.4w% of Ge, 6.0w%-9.0w% of Fe, 29.0w%-31.0w% of Ag and the balance copper. Thenickel-free low-silver-content Tibetan silver alloy is a novel nickel-free Tibetan silver alloy which does not exist in the market, and has excellent die-casting performance; and through industrialization of the alloy, the problem of the current Tibetan silver alloy can be solved, and the variety of the low-silver-content alloy for jewelry in the market can be greatly enriched.

The invention relates to a furan resin sand mold for producing heavy castings and a sand core bumping method. According to the technical scheme of the invention, the bumping method comprises the following steps of: a, correcting a table-surface level of a bumper first when the bumper is arranged and then checking up accelerations at four corners of the table-surface by using a seismometer and keeping the numerical values of the accelerations of the four angles to between 20 and 30 m / s<2>; b, adding a furan resin and a furan self-hardening sulfuric curing agent into molding sand and stirring the mixture to obtain sand mud for making mold and core sands, wherein the added weight of the furan resin is 0.95 to 1.15 percent based on the added weight of the molding sand and the added weight of the furan self-hardening sulfuric curing agent is 35 to 45 percent based on the added weight of the furan resin and the sulfuric acid in the furan self-hardening sulfuric curing agent is 9 to 35 percent by weight; and c, pouring the sand mud into a box till the level of the sand mud is 100 to 150 millimeters higher than the box surface and then starting the bumper to perform bumping for 10 to 50 seconds. The method has the advantages of greatly improving the percent of pass, greatly improving the loosening conditions of the casting and greatly reducing the rejection rate.

The invention relates to a casting process, in particular to a low-temperature ferrite ductile cast iron auxiliary casting test block preparation method. In order to solve the problem of totally consistent performances of an auxiliary casting test block and a casting, the invention proposes the low-temperature ferrite ductile cast iron auxiliary casting test block preparation method. The low-temperature ferrite ductile cast iron auxiliary casting test block preparation method uses a pouring system, a casting mold and an auxiliary casting test block mold; the uppermost end of the auxiliary casting test block mold is connected with the casting through a test block sprue connecting way; an overflow way is formed above the auxiliary casting test block mold; cold iron is put in the auxiliary casting test block performance taking place on the lower side of the auxiliary casting test block mold; and the auxiliary casting test block mold is vertically placed. Through transformation, a prepared auxiliary casting test block and a single casting Y-shaped test block have similar performances to reflect real casting performances.

The invention provides a method for preparing a shell for investment casting. The method comprises more than two shell layer preparation steps, at least part of the shell layer preparation steps comprises the steps of slurry coating, sand spraying and drying which are carried out in sequence, at least one shell layer preparation step further comprises a local isolation step, and in the local isolation step, an isolating membrane is arranged at the position, needing thickness control, of the shell. The invention also provides the shell prepared by using the method. The ceramic shell prepared through the method is high in thickness uniformity, and shrinkage porosity and grain control of the local area of a precision casting are facilitated. The invention further relates to a gas turbine blade shell prepared by using the preparation method.

The invention relates to a single cylinder diesel engine body and particularly relates to a vermicular graphite cast iron single cylinder diesel engine body with high vermicular graphite rate. The single cylinder diesel engine body comprises the following chemical components in percentage by mass: 3.5-3.8% of C, 2.1-2.6% of Si, 0.5-0.8% of Mn, less than 0.08% of P, less than 0.03% of S and the balance of iron and inevitable impurities. The single cylinder diesel engine body provided by the invention has the characteristics of less inclination of shrinkage cavity and shrinkage porosity and long service life. The invention further provides a preparation method of the single cylinder diesel engine body, which is reasonable in process.

The invention discloses a large cylindrical shell aluminum alloy casting low-pressure casting and shrinking control device. The large cylindrical shell aluminum alloy casting low-pressure casting and shrinking control device comprises a sand box, a casting, a pouring system, vibrators and vibration guide rods. The vibration guide rods are connected between a vertical cylinder pouring channel of the pouring system and the sand box. The vibrators are arranged on the outer surface of the sand box. The vibration direction of the vibrators is in line with the direction of the guide rods and tightly connected with the guide rods. The vibrators are adopted for providing a vibration source, the vibration guide rods are used for vibrating and guiding the casting and vibration is generated in the casting. Vibration transmitted by the guide rods is used for eliminating shrinking formed in the casting in the solidifying process. The vibrators vibrate in the normal direction of the outer surface of the cylindrical sand box and the guide rods are arranged in the normal direction of the outer surface of the sand box and coincide with the vibration direction of the vibrators. Meanwhile, the direction of the guide rods is parallel to the normal direction of the outer surface of the casting. According to the large cylindrical shell aluminum alloy casting low-pressure and shrinking control device, the density of the casting is reduced, the tendency to shrinking of the casting is relieved and the qualification rate of the casting is greatly improved.

The invention provides a sand core structure for cylinder cover casting tappet hole precasting and a precasting method. The sand core structure comprises a tappet hole sand core used for forming a casting tappet hole and a supporting sand core used for supporting the tappet hole sand core. The supporting sand cores are distributed and connected to the base core at intervals, the supporting sand cores are arranged on the base core in an embedded mode, and the upper surfaces of the supporting sand cores and the base core are located on the same horizontal plane; at least two tappet hole sand cores are obliquely arranged on the supporting sand core, and a set included angle is formed between the inclination angle of the at least two tappet hole sand cores and the ground plane. The tappet hole sand core is additionally arranged, the tappet hole structure is achieved in a pre-casting mode, and the problem of high cost caused by machining is solved; in addition, the invention further provides a precasting method, the tappet hole position machining allowance is omitted, and molten iron consumption is reduced.

The invention discloses a novel sliding valve pair for a railway vehicle brake valve. The novel sliding valve pair comprises a sliding valve and a sliding valve sleeve which are both made of brand-new materials, so that abrasion resistance of the sliding valve pair is enhanced. The sliding valve is soft, the sliding valve sleeve is hard, the sliding valve sleeve is long in service life, and the sliding valve is easy and convenient to repair and maintain.

A process method for a thin plate NdFeB ingot characterizes in purifying the NaFeB melt and controlling the cooling speed of the ingot after casting, in which, the purification is to add Ca and its alloy and let the melt pass through a pouring cup with a mini-hole foam ceramic filter plate to enter into the mold and the control of the cooling speed is realized by using a flat mold made of Cu and its alloy attached by two water cooling cover dies at its both sides to greatly reduce impurities in the ingot and refine the grains so as to improve the structure and increase the rate of finished products.

The invention discloses high-wear-resistance long-life ductile iron, comprising, by weight, 3.80-3.88% of C, 2.20-2.30% of Si, 0.55-0.65% of Mn, < / =0.020% of P, < / =0.010% of S, 0.45-0.55% of Cu, 0.30-0.40% of Mo, 0.0040-0.0060% of La, 0.035-0.045% of Mg, and the balance of iron and unavoidable impurity. The invention is intended to provide the high-wear-resistance long-life ductile iron that has high rigidity and fatigue strength and has improved tensile strength and plasticity, and a method of producing a lower cylinder with the ductile iron.

The invention discloses a sampling device for accurate quantification of carbon content in spheroidal graphite cast iron and additionally discloses a sampling method using the sampling device for the accurate quantification of the carbon content in the spheroidal graphite cast iron. According to the technical scheme of the invention, the sampling device for the accurate quantification of the carbon content in the spheroidal graphite cast iron comprises a sampling base and a sampling handle. A sampling cavity is arranged on the sampling base. The wall surface of the sampling cavity is a spherical crown surface. The sampling handle comprises an operating handle and a sampling ball. The sampling ball is connected with the bottom end part of the operating handle. The diameter of the sampling ball is the same as the diameter of the sampling cavity. By using the device, the precision of carbon content detection is improved, the operation is convenient and the shrinkage trend of castings is reduced.

A vagina-expanding blade for an obstetrics and gynecology speculum. The vagina-expanding blade is divided into upper and lower pieces, and the upper and lower two pieces of the vagina-expanding blade cooperate. The main body of the vagina-expanding blade is made of copper alloy. The surface treatment layer, the nickel alloy coating layer of the present invention is passivated and sealed after the surface is smooth and easy to clean, the corrosion resistance is effectively improved, there is no harm in contact with human epidermis, and it has a certain antibacterial effect.

The invention relates to vermicular graphite cast iron with a high rate of vermiculation of a combustion motor cylinder body and a cylinder cover and a preparation method, and belongs to the field of casting method. The vermicular graphite cast iron with the high rate of the vermiculation of the combustion motor cylinder body and the cylinder cover and the preparation method are characterized in that the vermicular graphite cast iron with the high rate of the vermiculation comprises the following chemical components: 3.4%-3.7% of carbon, 2.0%-2.5% of silicon, 0.5%-0.8% of manganese, 0%-0.08% of phosphorus and 0%-0.04% of sulphur, with the balance being iron. In a microscopic structure, a pearlite area accounts for 50%-70%, a ferrite area accounts for 30%-50%. The mechanical properties are as follows: strength of extension sigma b is more than or equal to 320 MPa to 400 MPa, ductility delta is 1%-4%, and hardness HB is 160-230. Due to the fact that molten iron component is near an eutectic point, scope of crystallization is narrow, liquidity is good, casting performance is good, the tendency of a casting shrinkage cavity and shrinkage porosity is little, a wholesome cylinder cover cast and wholesome cylinder body cast are easy to obtain, the service lives of the cylinder cover and the cylinder body are prolonged, certainly, the vermicular graphite cast iron with the high rate of the vermiculation of the combustion motor cylinder body and the cylinder cover and the preparation method play a pivotal role of the performance of improving the combustion motor and prolonging the service life of the combustion motor.