Development and Testing of novel Casted&Wrought GH4096 Alloy Labyrinth Disk

Abstract:

The GH4096 alloy aero-engine labyrinth disk forging was produced by a novel casting wrought method which included electroslag remelting continuous directional solidification, multiple integral forging and isothermal forging and other process. Different cooling rate after solid solution treatment was analyzed on the effect of microstructure and properties of forgings. Microstructure of forgings were analyzed by optical microscope (OM) and scanning electron microscope (SEM). Mechanical properties of forgings were tested, multi-zoned ultrasonic focused inspection was uesd to detect the quality of GH4096 alloy forgings. In addition, full-size labyrinth disks were manufactured and tested. Test results show that two kinds of heat treated forgings process the comparable grain size about 5~20μm and firstly γ’ size about 1~2μm. Compare to oil cooling of solution treated forgings, the forced air cooling of solution treated forgings processes coarser secondary and thirdly γ’ phase, less thirdly γ’ phase content, lower yield strength,lower creep property, lower residual stress and machining deformation. There is no single reflected signal higher than that of Φ0.4mm-15dB, and the clutter signals are lower than Φ0.4mm-21dB. The forced air cooled solution + aging treated full-size GH4096 alloy labyrinth disk passed the over-running test and burst speed test.

Key words:GH4096 alloy; novel casting& wrought method; microstructure; mechanical property; residual stress; ultrasonic inspection