收敛调节片底板后段精密铸造工艺

Investment Casting on the Back Section of a Convergent Regulator Plate

收敛调节片底板后段精铸件,其为航空发动机收扩喷口处的薄壁结构件,采用JG4246A合金熔模铸造成形。试制过程中铸件在底板、筋条位置极易产生裂纹、缩松等缺陷,导致铸件合格率下降。通过优化浇注系统,调整型壳保温毡包裹方式、预热温度和浇注参数等措施,最终确定了控制模组浇注系统、型壳包裹的要点、浇注注意事项及后续清理工作的控制措施,减少了裂纹、缩松等缺陷,铸造合格率达到85%。

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%.