Abstract
Accelerated oxidation tests have been conducted on a number of Co-Cr, Co-Al, and Co-Cr-Al alloys coated with a thin film of Na2SO4 and exposed at 600 to 750 °C in O2-SO2-SO3 environments containing 0.0095-5 pct (SO2 + SO3). Generally, Co-Cr and Co-Cr-Al alloys reacted nonuniformly, usually in the form of pits, and Co-Al alloys suffered broad frontal attack. The morphology of the reaction product was observed to be dependent on temperature andP SO3 Under all conditions, a thin sulfur-rich band containing sulfides was observed at the alloy/scale interface, and cobalt dissolved near this interface and formed Co3O4 and/or CoSO4(s) in different regions of the reaction product.
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Luthra, K.L. Low Temperature Hot Corrosion of Cobalt-Base Alloys: PartI. Morphology of the Reaction Product. Metall Trans A 13, 1843–1852 (1982). https://doi.org/10.1007/BF02647841
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DOI: https://doi.org/10.1007/BF02647841