A precision casting method for the rear cover of a spiral supercharged diffuser

Abstract

The invention discloses a precision casting method of the back cover of a spiral supercharging diffuser. The casting method comprises steps of wax member preparation, assembling, slurry dipping and shell manufacturing, de-waxing, burning, casting, shell breaking, and cleaning. In the wax member preparation step, a cold wax core is manufactured through a cold wax core mould, then the cold wax core is allowed to stand still, and after the standing time is longer than four hours, the cold wax core is placed into a diffuser back cover mould to assemble a wax member. In the assembling step, the assembled wax member is trimmed and then adhered, and a casting system with a cast gate, a runner, and a sink head is combined with the wax member. In the slurry dipping and shell manufacturing step, after the wax member and the casting system are combined to form an assembled member, slurry is painted on the periphery of the assembled member. The tendencies of shrinkage hole and shrinkage porosity in the casting are reduced by the provided method, and the qualified rate of the casting is improved therefor.

Description

technical field [0001] The invention relates to a precision casting method for a diffuser part, in particular to a precision casting method suitable for a rear cover of a diffuser, and belongs to the technical field of precision casting. Background technique [0002] The material of the U-shaped ultra-high pressure spiral booster diffuser is generally austenitic cast stainless steel, which is a key part of the U-shaped multi-stage spiral booster diffuser assembly and welding structure. The large plane of the rear cover casting is assembled and welded with the diffuser body. After the product is welded, the working pressure is required to be greater than 3000Psi. Because the wall thickness of the back cover casting is greater than 50mm, in the process of making wax parts by precision casting, the wax parts are prone to deformation due to shrinkage, resulting in out-of-tolerance casting sizes, resulting in poor dimensional accuracy of castings. At the same time, due to the wal...

AI Technical Summary

Problems solved by technology

After the product is welded, the working pressure is required to be greater than 3000Psi. Because the wall thickness of the back cover casting is greater than 50mm, in the process of making wax parts by precision casting, the wax parts are prone to deformation due to shrinkage, resulting in out-of-tolerance casting sizes, resulting in poor dimensional accuracy of castings. Qualified, at the same time, due to the thickness of the casting wall, shrinkage porosity is prone to occur in the center of the casting, and shrinkage cavities are generated at the gate, which affects the welding process of the casting and makes the product fail to meet the technical requirements of the working pressure greater than 3000Psi

Images