Turbine Blade Refurbishment
Abstract
An investigation of metallurgical improvements and repair procedures to extend the service life to F404 high pressure turbine blades has been conducted. The first phase of the investigation was directed towards the evaluation of directionally solidified Rene'80H superalloy specimens and blades and has been previously published. In the study reported herein, the elevated temperature creep-rupture properties of single crystal Rene'N4 specimens were determined and compared to the creep properties of the directionally solidified Rene'80H specimens. For the range of stresses and temperatures investigated, the creep-rupture life of single crystal specimens was at least twice that of the directionally solidified specimens. In addition, it was proposed to extend the life of turbine blades by refurbishment of damaged blade tips with MERL 72 weld overlays. The creep-rupture behavior and interfacial integrity of composite Rene'N4/ MERL 72 specimens was found to be satisfactory and comparable to composite Rene'80H/MERL 72 specimens. Comparisons of creep performance of single weld specimens (to simulate a tip repair) and re-weld specimens (to simulate a second tip repair) showed that the creep life of re-welded specimens was reduced compared to the single weld condition. The creep results and metallographic observations of the creep failure processes are presented and discussed.... Nickel-base superalloys, Microstructures, Creep-rupture, Elevated temperatures, Strength, Mechanical properties.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 12, 1993
- Accession Number
- ADA267124
Entities
People
- David J. Michel
- Hugh H. Smith
Organizations
- United States Naval Research Laboratory