Navy Product Improvement Program for Turbomach T-62T APU's-Corrosion Resistant Turbine Wheel/Improved Bearing and Lubrication System.
Abstract
Titan T-27 and T-40-1 gas turbine engines have used IN-713 LC turbine wheels for many years without serious hot corrosion problems. For extended operation in marine environments, however, the well-known susceptibility of Alloy 713 to hot corrosion (sulfidation) could lead to deterioration of airfoil surfaces resulting eventually in loss of engine performance, or even engine failure. Corrosion protection could be enhanced by protective coatings; however, with base material so poor in hot corrosion resistance as Alloy 713, the reliability of a 713 turbine wheel would be suspect. Also, the degradation of mechanical properties accompanying the coating process would reduce the safety margin below acceptable appears to be a material change to an alloy with better hot corrosion resistance. The alloy selected was MAR-M247, a nickel-based alloy with 10 percent cobalt, 10 percent tungsten, 8,25 percent chromium, 5.5 percent aluminum, 3 percent tantalum, 1.5 percent hafnium, 1 percent titanium, and other elements. The expected improvements over IN-713 LC include improved oxidation/hot corrosion resistance, blade creep resistance, and tensile strength.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 12, 1986
- Accession Number
- ADA178084
Entities
People
- Wade A. Robertson