Fast investment casting technology of stainless steel impeller employing 3D printing solid mould

Abstract

The invention discloses a fast investment casting technology of a stainless steel impeller employing a 3D printing solid mould in the field of the investment casting technology. The fast investment casting technology comprises the following steps: arranging a venting pore channel in the 3D printing solid mould, and then sealing the venting pore channel with ordinary wax; welding the solid mould and a molten mould into a whole to form a mould group; coating the surface of the mould group with modified silica sol to form an integral mould shell; removing a mould shell closing the venting pore channel from the integral mould shell, melting the molten mould and the ordinary wax; airing, putting the whole formed by the mould shell and the solid mould into a roasting furnace in a state that the solid mould is positioned on the upper part, ablating the solid mould in an oxygen-riched state, closing a furnace door after sufficient combustion, stopping the furnace after sufficient ablation, cooling and taking out the mould shell; washing the mould shell to remove residues and residual ash, and then sealing a part, removed in the former step, of the mould shell; putting the mould shell into the roasting furnace, roasting, and then casting high-temperature metal melt to obtain a cast. The fast investment casting technology has the advantages of low manufacturing cost, high production efficiency, low possibility of mould shell cracking and the like.

Description

technical field [0001] The invention relates to an investment precision casting process, in particular to a rapid investment casting process of a stainless steel impeller that can be matched with a 3D printed solid mold. Background technique [0002] The impeller is the core component of a centrifugal pump. The blades of the impeller usually have irregular curved surfaces and a very complex structure, and the impeller often has many fine structures inside. In order to ensure the reliability of the impeller during operation, the quality indicators such as dimensional accuracy, shape tolerance and surface roughness are very high. For the production of impeller castings, the investment casting process is generally adopted in the industry. The investment casting process has many production processes, long cycles, many factors affecting quality and relatively complicated control. Among them, the casting process of the impeller and the design of the gating system and the pressure ...

AI Technical Summary

Problems solved by technology

For the production of impeller castings, the investment casting process is generally adopted in the industry. The investment casting process has many production processes, long cycles, many factors affecting quality and relatively complicated control. Among them, the casting process of the impeller and the design of the gating system and the pressure profile design And the adjustment of the difference between the manufacturing and the actual production structure usually requires a long adjustment process, which leads to high mold manufacturing costs and long production cycles

Especially for complex impeller castings and large impeller castings, the cost of trial production is very high, which greatly increases the burden on the enterprise, and will also seriously affect the trial production of subsequent new products

In addition, during the roasting process, it is often accompanied by incomplete combustion and the occurrence of thermal expansion of the air inside the shell, which causes the shell to be easily cracked and residues will be formed in the shell, resulting in defects such as slag inclusions and pores in the precision casting. Scrapped, seriously affecting normal production