Marine Gas Turbine Hot Corrosion Dependence on Ingested Salt Levels.
Abstract
Turbine section hardware in marine engines is susceptible to hot corrosion attack induced by salt deposition. In attempting to control this type of materials degradation, it is necessary to examine the dependence of hot corrosion on ingested salt level and to determine the deposition rate below which hot corrosion attack will be negligible. Test specimens (uncoated and aluminized Mar-M509 and IN792, CoCrAlY-coated IN 792) were exposed at 700 and 900 C in laboratory tube furnaces to conditions which induce hot corrosion attack. The microstructures developed in these tests were compared with those observed in service hardware. A test at 700 C with a salt deposit of sodium sulfate, either pure or mixed with metallic sulfates, and a gaseous environment of oxygen with approximately .0001 atm SO3 was found to most closely duplicate the degradation microstructure most common in hardware from marine service. Results support the hypothesis that any condensed salt deposit is likely to produce unacceptable hot corrosion and hence the only safe ingestion level is that which produces no salt deposition on turbine hardware.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 16, 1979
- Accession Number
- ADA071055
Entities
People
- F. S. Pettit
- R. H. Barkalow
Organizations
- Pratt & Whitney