Nickel-Based Super Alloy Turbine Disk for Gas Turbine

  

Superalloy turbine wheel used for Locomotive and Marine turbocharger, turbine wheel be finished by integral casting. And casting method of turbine wheel is lost wax  investment & vacuum casting, casting surface smoothness can meet Ra3.2μm-Ra1.6, production process of turbine wheel is Silica sol process. The blade thickness is 0.5mm. For turbine wheel, we can do the kinds of type: radial turbine wheel and axial turbine wheel.
 

According to the different wax materials and shell materials used, wax mold investment casting is divided into: low temperature wax -- water glass process; Medium temperature wax - silica sol process and composite process.

At present, the process used by our company is medium temperature wax-silica sol process.
The advantage of this process is that the surface of the castings made has high finish and high precision, but the disadvantage is that the cost is high.
In terms of finish, generally the surface after lathe processing can reach Ra1.6, the finish of the casting completed by our company is between 1.6 and 3.2, while the finish of low temperature wax casting is between 6.3-9, and the finish of ordinary casting is even lower, reaching 12.3.


5. Prepare raw materials. Stainless steel or superalloy. The composition of the material is measured using spectrometers.
6. The shell is roasted before casting, and the high-temperature alloy is roasted to more than 1000 degrees, and the stainless steel is generally roasted at 800-900 degrees
The purpose of burning the shell: 1) to burn the wax remaining in the mold shell
2) Preheat the shell and reduce the temperature difference to make the injected metal liquid good. Because if the difference between the temperature in the shell and the temperature of the metal liquid is too large, it is easy to cause the shell to break and is not conducive to the molding of the casting.