Hot Isostatic Pressing/Heat Treatment of Cast Superalloy AF2-1DA, Radial Turbine Wheels.
Final rept. 6 May 75-15 Jul 79,
AIRESEARCH MFG CO OF ARIZONA PHOENIX
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Forty AF2-1DA alloy radial turbine wheels were cast and X-ray inspected. Thirty-eight wheels were free of obvious defects and selected for evaluation. As-cast elevated temperature tensile strength was measured and as-castheat threated tensile and stress-rupture properties were determined. Eight wheels were HIPped in four combinations with temperatures varying from 2150 to 2250 F, pressures of 15 or 29 ksi, and a constant three-hour time period. Four solution heat treatment temperatures were selected based on a previous investigation to cast a modified AF2-1DA alloy composition AFML Contract Number F33615-71-C-1573. Evaluations were performed using four HIP conditions and eight HIPheat treatment combinations of four wheels each. Samples were examined metallographically and tensile and stress-rupture properties were determined. Four HIPheat treatment combinations were selected for LCF testing on the basis of acceptable microstructures and mechanical properties. Room temperature strain-control LCF tests were performed and results analyzed on a Weibull distribution. Data analysis indicated that LCF life improvement was obtained through HIP and heat treatment. Specifically, a 3X LCF life improvement was achieved for as-cast wheels predicted to fail in less than 1000 cycles. Author
- Properties of Metals and Alloys
- Fabrication Metallurgy