Hot corrosion of cobalt-base alloys. Final technical report 1 Jun 1972--31 May 1975

Technical Report · Sun Jun 01 04:00:00 EDT 1975

OSTI ID:7251797

Goebel, J A; Pettit, F S

The sodium sulfate-induced hot corrosion of cobalt and a number of binary, ternary and quaternary cobalt-based alloys containing aluminum, chromium, tungsten, molybdenum, tantalum, titanium and yttrium has been studied at 1000-degrees Celcius in 1 atm of oxygen or air. The studies consisted of both laboratory experiments and testing with a dynamic burner rig. The results obtained from these studies were compared to those available for equivalent nickel-base systems. Those obtained from laboratory tests were in satisfactory agreement with those from dynamic burner rigs except that the loss of chromium from the alloys was more pronounced in the high velocity rig tests. It was determined that sodium sulfate deposits caused increased oxidation of all of the alloys studied. Mechanisms for the hot corrosion of these alloys have been developed. A substantial difference between the hot corrosion resistance of cobalt- and nickel-base alloys has been observed only for alloys containing chromium and aluminum with no refractory elements. Chromium and yttrium produced beneficial effects on the hot corrosion of alloys; aluminum also produced beneficial effects except at low concentrations of aluminum. Molybdenum and tungsten usually produced deleterious effects on the hot corrosion of alloys whereas tantalum and titanium were apparently innocuous. (Author) (GRA)

• Research Organization: Pratt and Whitney Aircraft, East Hartford, Conn. (USA)
• OSTI ID: 7251797
• Report Number(s): AD-A-024425; PWA-5379
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COBALT ALLOYS
COBALT BASE ALLOYS
CORROSION
MOLYBDENUM ALLOYS
OXYGEN COMPOUNDS
SODIUM COMPOUNDS
SODIUM SULFATES
SULFATES
SULFUR COMPOUNDS
TANTALUM ALLOYS
TITANIUM ALLOYS
TUNGSTEN ALLOYS
VERY HIGH TEMPERATURE
YTTRIUM ALLOYS