A production method for producing cast parts from metal using a sand casting mold (1). The sand casting mold (1) is produced in this case in a molding box (2) by means of a negative-pressure molding method. According to the invention, the sand casting mold (1), which is under negative pressure, in the molding box (2) is first of all filled with molten metal (5). The molding box (2) with the sand casting mold (1), which is under negative pressure therein, is then completely or partially impinged upon by a cooling fluid (4) and after, at the same time as, or before the cooling fluid impingement is opened at places with cooling fluid impingement. As a result of this, cooling fluid (4) is sucked into the sand casting mold (1) which is under negative pressure, as a result of which the solidifying cast part (3) is quenched more quickly.

A production method for producing cast parts from metal using a sand casting mold (1). The sand casting mold (1) is produced in this case in a molding box (2) by means of a negative-pressure molding method. According to the invention, the sand casting mold (1), which is under negative pressure, in the molding box (2) is first of all filled with molten metal (5). The molding box (2) with the sand casting mold (1), which is under negative pressure therein, is then completely or partially impinged upon by a cooling fluid (4) and after, at the same time as, or before the cooling fluid impingement is opened at places with cooling fluid impingement. As a result of this, cooling fluid (4) is sucked into the sand casting mold (1) which is under negative pressure, as a result of which the solidifying cast part (3) is quenched more quickly.

A cast-iron casting, method for manufacturing a cast-iron casting, and equipment for manufacturing a cast-iron casting, which are capable of performing a plating or enameling treatment without defects on a surface of the cast-iron casting, regardless of its specifications, without decreasing productivity or increasing manufacturing costs. A mold is molded by decompressing molding sand, and a melt is poured into the mold. The inside of the mold is decompressed until the temperature of a casting formed by the melt falls to or below an A.sub.1 transformation point. The equipment includes: at least one mold; a frame feed device that moves the mold; at least one fixed suction device that decompresses the inside of the mold when stopped; at least one movable suction device that moves while decompressing the inside of the mold when the mold is moving; and a temperature sensor that measures the product surface temperature of the casting.

A cast-iron casting, method for manufacturing a cast-iron casting, and equipment for manufacturing a cast-iron casting, which are capable of performing a plating or enameling treatment without defects on a surface of the cast-iron casting, regardless of its specifications, without decreasing productivity or increasing manufacturing costs. A mold is molded by decompressing molding sand, and a melt is poured into the mold. The inside of the mold is decompressed until the temperature of a casting formed by the melt falls to or below an A.sub.1 transformation point. The equipment includes: at least one mold; a frame feed device that moves the mold; at least one fixed suction device that decompresses the inside of the mold when stopped; at least one movable suction device that moves while decompressing the inside of the mold when the mold is moving; and a temperature sensor that measures the product surface temperature of the casting.

A method for preparing a negative pressure film-covering frozen sand mold includes: directly obtaining a mold cavity of a sand mold through numerically controlled machining of a frozen sand blank; covering a surface, brushed with a thermal insulation coating, of the mold cavity of the sand mold with a softened thin film, and covering an outer surface of the sand mold with a back film to seal a sand box; fixing the frozen sand mold in an air extraction sand box with a vacuum chamber, and extracting air through a vacuum pump, so that the thin film tightly adheres to the sand mold through vacuum suction force; and closing the box to obtain an integral sand mold, and pouring a casting at room temperature or low temperature under negative pressure. The method is environment-friendly, and the prepared frozen sand mold has high strength and is convenient for sand cleaning.

A method for preparing a negative pressure film-covering frozen sand mold includes: directly obtaining a mold cavity of a sand mold through numerically controlled machining of a frozen sand blank; covering a surface, brushed with a thermal insulation coating, of the mold cavity of the sand mold with a softened thin film, and covering an outer surface of the sand mold with a back film to seal a sand box; fixing the frozen sand mold in an air extraction sand box with a vacuum chamber, and extracting air through a vacuum pump, so that the thin film tightly adheres to the sand mold through vacuum suction force; and closing the box to obtain an integral sand mold, and pouring a casting at room temperature or low temperature under negative pressure. The method is environment-friendly, and the prepared frozen sand mold has high strength and is convenient for sand cleaning.

A production method for producing cast parts from metal using a sand casting mould (1). The sand casting mould (1) is produced in this case in a moulding box (2) by means of a negative-pressure moulding method. According to the invention, the sand casting mould (1), which is under negative pressure, in the moulding box (2) is first of all filled with molten metal (5). The moulding box (2) with the sand casting mould (1), which is under negative pressure therein, is then completely or partially impinged upon by a cooling fluid (4) and after, at the same time as, or before the cooling fluid impingement is opened at places with cooling fluid impingement. As a result of this, cooling fluid (4) is sucked into the sand casting mould (1) which is under negative pressure, as a result of which the solidifying cast part (3) is quenched more quickly.

The present invention provides an integrally cast excavator bucket and a manufacturing method thereof. The integrally cast excavator bucket comprises a lifting lug, a top plate, two side plates and a bottom plate connected with the two side plates. A method for manufacturing the integrally cast excavator bucket by adopting the cast steel comprises the following steps: putting cast steel components into a melting furnace, and carrying out modification treatment before furnace after melting is finished; manufacturing models and a template, coating, heating, vacuumizing, placing sandboxes, adding sand, molding, carrying out mold closing, casting, quenching, tempering and cooling to room temperature to finish casting of the excavator bucket. The integrally cast excavator bucket is formed by once casting from a low-alloy steel material by adopting a vacuum sealing technology, and is high in product strength, resistant to wear and corrosion, high in impact resistance and long in service life.

The present invention provides an integrally cast excavator bucket and a manufacturing method thereof. The integrally cast excavator bucket comprises a lifting lug, a top plate, two side plates and a bottom plate connected with the two side plates. A method for manufacturing the integrally cast excavator bucket by adopting the cast steel comprises the following steps: putting cast steel components into a melting furnace, and carrying out modification treatment before furnace after melting is finished; manufacturing models and a template, coating, heating, vacuumizing, placing sandboxes, adding sand, molding, carrying out mold closing, casting, quenching, tempering and cooling to room temperature to finish casting of the excavator bucket. The integrally cast excavator bucket is formed by once casting from a low-alloy steel material by adopting a vacuum sealing technology, and is high in product strength, resistant to wear and corrosion, high in impact resistance and long in service life.

A cast metal railroad car wheel includes a hub section, a tread section, and an uninterrupted annular web extending between and supporting the tread section on the hub section. The web includes a disk-shaped surface that is continuously concave and that does not include a reversely curved portion. A V-process casting process casts railroad wheels using a vacuum-process casting mold with opposing halves each partially filled with unbonded sand and sand-retaining-plastic film and a vacuum application port and that, when positioned together with the unbonded sand held to shape by vacuum and the film, define a cavity shaped to form a railroad car wheel. The V-process includes feeding molten metal into the cavity, cooling the molten metal, and releasing a vacuum to cause the sand to fall away from the railroad car wheel.