The investment castings of the back section of convergent regulator plate were investigated

which is a typical thin-walled structure for the nozzle of aero-engine

formed by investment casting of JG4246 Asuperalloy.During the process of trial production

metallurgical defects such as crack and shrinkage are easily generated at the casting base plate and rib strip

leading to decrease of qualified rate.By optimizing the gating system and adjusting the wrapping mode of shell insulation felt

preheating temperature and pouring parameters

the key to control module gating system and shell wrapping

and the casting precautions

as well as the control measures for subsequent cleaning work were determined

thus reducing the metallurgical defects

raising the qualified rate to 85%.