Rejuvenation of Turbine Blade Material by Thermal Treatment.
Abstract
This report describes a two phase program designed to investigate the feasibility of applying thermal treatments at some fraction of a turbine blade's life to heal accumulated fatigue and creep damage thereby extending useful blade life. Test evaluations were conducted on cast test bars of two nickel-base superalloys: conventionally cast (CC) In 100 alloy and directionally solidified (DS) MAR-M200 + Hf. In Phase I, creep testing of cast specimens was used to select suitable rejuvenation heat treatments based upon recoverable creep life and strain. The effect of creep strain and subsequent rejuvenation on minimum mechnical property requirements and the maximum recoverable creep strain was also determined. In addition, the use of eddy current inspection was investigated as a method to provide specific NDI criteria for selection of components suitable for rejuvenation processing. The Phase II effort included determinations of the effectiveness of rejuvenation heat treatments in recovering repeated creep strain damage and in recovering specific amounts of low-cycle and high-cycle fatigue life. In addition, the effects of rejuvenation heat treatments in recovering cumulative creep/fatigue strain damage was determined. Finally an assessment was made of the technical and economic feasibility for extending useful turbine blade life by rejuvenation thermal treatments. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1979
- Accession Number
- ADA077527
Entities
People
- Dennis C. Stewart
- Gary T. Bennett
- Mike D. Ross
Organizations
- Pratt & Whitney