CORROSION OF SUPER-ALLOYS BY SELECTED FUSED SALTS. Period covered: March 15, 1959-February 15, 1960

Technical Report · Mon Feb 15 04:00:00 EST 1960

OSTI ID:4084529

Moskowitz, A; Redmerski, L

S>Corrosion of Inconel X, Inconel 702, Rene 41, M-252, and Haynes 25 by KCl and LiF at 1600 to 1900 deg F was studied. Thin coatings of the salts (1.5 mg/cm/sup 2/) caused severe corrosion of the alloys in air which resulted in accelerated failures of thin sheet specimens in creep-rupture tests. Rankings for the alloys based on these tests were similar for uncoated and coated materials: Haynes 25, Rene 41, and M-252 best, Inconel 702 poorer, and Inconel X poorest. Corrosion products consist of oxides and spinels. Very little corrosion occurs without oxygen. The presence of the salt prevents the normal formation of a protective oxide film. X-ray diffraction studies showed differences between the normal oxidation products and the oxide corrosion products produced with salt present. The corrosion occurs as severe surface attack with consequent eroding away of metal, as intergranular penetration, and as internal voids formed in the alloy. All the alloys were susceptible to each of these types of corrosion. Grain boundary separation effects due to stress (2500 to 10,000 psi) were also found. (auth)

• Research Organization: Crucible Steel Co. of America, Pittsburgh
• NSA Number: NSA-15-005329
• OSTI ID: 4084529
• Report Number(s): WADD-TR-60-115; AD-237941
• Country of Publication: United States
• Language: English

Related Subjects

AIR
ALKALI METALS
ALKALINE EARTH METALS
ALUMINUM OXIDES
COATING
CORROSION
CREEP
DIFFRACTION
FAILURES
LITHIUM FLUORIDES
MATERIALS TESTING
METALS, CERAMICS, AND OTHER MATERIALS
NICKEL ALLOYS
OXIDES
POTASSIUM CHLORIDES
RUPTURE
STRESSES
X RADIATION