Improvement of lost foam casting process for turbine rear exhaust pipe

According to the numerical simulation of turbine rear exhaust pipe in lost foam casting, under the existing process conditions, due to different gating systems, there is no shrinkage cavity and porosity at the bottom of lost foam casting, but only insufficient pouring and shrinkage cavity and porosity at the top, so as to control the insufficient pouring The most common method for shrinkage defects is to increase the riser. Add a riser at the part where the defect occurs, so as to achieve the feeding effect.

According to the basic principles of lost foam casting riser design and the defective parts in the simulation results, we can determine the position and size of the riser, set the riser at the top plane part of the lost foam casting that is the highest and thickest and conducive to machining, and the size of the lost foam casting riser meets the amount of liquid metal replenishment and shrinkage.