EFFECT OF SULFUR IN JP-5 FUEL ON HOT CORROSION OF COATED SUPERALLOYS IN MARINE ENVIRONMENT
Abstract
Specimens of a nickel-base alloy (Mar M-200) with an aluminum- diffusion coating (Misco MDC-1) were tested using a high-pressure combustor facility to simulate environment in the turbine section of an aircraft engine. Tests were conducted at 2000 F gas temperature, without sea salt and with 1.0 ppm sea salt in air, using three levels of sulfur in fuel (0.40, 0.040 and <0. 0040 per cent by weight. A significant decrease in the relative rate of corrosion and the level of attack when sea salt was removed from the air indicated that sea salt is a primary cause in the hot corrosion of both bare and coated superalloys in a marine environment. The effect of sulfur in fuel varied with the absence or presence of sea salt. In the absence of sea salt, a reduction in sulfur from the present limit of 0.40 per cent for JP-5 fuel to 0. 040 per cent, or less, decreased hot corrosion; however, the level of attack was so low that the reduction may be of little practical significance. In the presence of 1.0 ppm sea salt in air, a reduction in sulfur to either 0.040 or <0.0040 per cent had no statistically significant effect on hot corrosion; but the experimental error was considerably greater with this coating-alloy system than with other systems evaluated that benefited from a reduction in sulfur to less than 0.0040 per cent.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1967
- Accession Number
- AD0819924
Entities
People
- H. T. Quigg
- R. M. Schirmer