Large-scale double-flange copper alloy shaft sleeve or copper alloy bearing bush centrifugal casting method

Abstract

The invention discloses a large-scale double-flange copper alloy shaft sleeve or copper alloy bearing bush centrifugal casting method which comprises the following steps of designing a process, designing a tool, and manufacturing the tool; assembling the tool, and filling water glass sand; perforating along the axial direction, and curing the water glass sand or resin sand; coating an inner mold;baking a combination mold; smelting copper alloy liquid; carrying out ladle analysis; starting a centrifugal casting machine, setting the rotating speed of the centrifugal casting machine, and casting; when the temperature of the copper alloy liquid reaches to the process design temperature, casting; removing an outer mold, firstly disassembling two head cover plates of the outer mold, and removing a casting workpiece, an inner sleeve mold and the filled water glass sand or the resin sand together; gas-cutting the inner sleeve mold: manually gas-cutting an inner sleeve mold piece for repeateduse; rough machining: machining the casting workpiece to a rough machining dimension after air cooling; and carrying out penetrant testing, heat treatment, and finish machining: rough machining the surface of the workpiece, carrying out penetrant testing, relieving stress after the requirement is met, and finish-machining according to a finished product drawing. The large-scale double-flange copper alloy shaft sleeve or copper alloy bearing bush centrifugal casting method provided by the invention has the advantages of saving raw materials and reducing working hours.

Description

technical field [0001] The invention relates to the technical field of casting, more specifically to the technical field of centrifugal casting technology, and more specifically to a centrifugal casting method for large-scale double-flange copper alloy bushings or copper alloy bearing bushes. Background technique [0002] Due to the unique structure of large-scale copper alloy double-flange bushings or copper alloy bearing bushes. The diameters of flanges and bushings or copper alloy bearings are quite different, and their seats are generally larger; therefore, the quality requirements for double-flange bushings or copper alloy bearings are relatively high, and it is necessary to ensure that the crystal structure of the workpiece is uniform and dense during casting. There must be no slag inclusions, pores and cracks; therefore, the causes of uneven crystal structure, non-compactness, slag inclusions, pores, and cracks must be eliminated in the casting process; in order to me...

AI Technical Summary

Problems solved by technology

[0003] 1) Sand mold gravity casting: As a result, due to the poor air permeability of the sand mold itself, the sequential crystallization of the copper alloy, and the slow cooling rate, the workpiece has large areas of slag inclusions, pores, and coarse crystals after machining, which cannot meet high requirements;

[0004] 2) Combined gravity casting with outer metal mold and sand core: the peripheral crystallization speed of the workpiece is fast, the crystallization speed of the inner contact surface with the sand core is slow, and the air permeability of the sand core is poor. Meet the requirements for use;

[0006] 4) Centrifugal casting with cold mold impacting sand: it is better for ordinary copper alloys (copper alloys that are not easy to segregate during crystallization), but for copper alloys containing heavy metal elements such as tin and lead, this method cannot meet the requirements; and tin elements are easy to segregate during centrifugal casting; the copper alloy crystal sheet is easy to segregate lead in the early stage, and under the action of centrifugal force, the segregated lead and a small amount of copper infiltrate into the impacted sand mold, so that the centrifugal workpiece produces lead-rich copper alloy and Molding sand mixture; it cannot be processed during machining, resulting in the scrapping of the workpiece;

[0007] 5) The metal mold is centrifugally cast into a straight sleeve and then machined into a double flange method: this method faces heavy centrifugal mold and copper alloy liquid, and the vibration of the centrifugal casting machine is serious; the speed of the centrifuge is difficult to meet the process requirements, resulting in copper alloy Defects such as slag inclusions and pores caused by the gas and oxides in the liquid cannot be exhausted smoothly, and the input of raw materials is large, the material loss is large, and the machining time is long, resulting in high production costs

Images