Sulfur in the Corrosion of Superalloys.
Abstract
This study was divided into three interrelated sections. These were (1) corrosion of nickel in SO2-O2-Ar gas mixtures at 800C; (2) defect structure of calcia- and of yttria-stabilized zirconia; and (3) diffusion of radio-tracer sulfur-35 and of tellurium 127m in calcia-stabilized zirconia. The corrosion study resulted in a confirmation of linear kinetics for corrosion of nickel in SO2-Argon gas mixtures at 800C and an agreement of a self-consistent mechanism involving the migration of SO2 as a gas molecule through the outer NiO layer and dissociation at the inner sulfide layer as a rate determining step. The corrosion kinetics in 20%O2-variable SO2-balance argon and in 30% SO2 variable O2-balance argon were extremely rapid. These data did not show that interconnected stringers of sulfide through the outer NiO layer was responsible for the observed kinetics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 06, 1981
- Accession Number
- ADA107867
Entities
People
- J. Bruce Wagner Jr.
Organizations
- Arizona State University