Effect of aging on anodic behavior of Ni--Cr--Mo alloys

Journal Article · Mon Oct 01 04:00:00 EDT 1973 · Corrosion, v. 29, no. 10, pp. 375-383

DOI:https://doi.org/10.5006/0010-9312-29.10.375· OSTI ID:4392804

Hodge, F G

The precipitation response of corrosion-resistant alloys based on the Ni- -Cr--Mo phase diagram is complex with both intermetallic and carbide phases being formed during aging in the 650 to 1O90 deg C range. Although these phases markedly affect the corrosion resistance, their composition and structure have not been fully defined. Data are presented to show that the precipitating intermetallic phase in Hastelloy alloy C-276 is a (Ni, Fe, Co)/sub 3/ (W, Mo Cr)/ sub 2/ Mu phase and the carbide is an M/sub 6/C. Both phases have been shown to significantly increase the anodic dissolution rate of the passive region in boiling 10% sulfuric acid. Intergranular attack on aged alloy C-276 samples occurred due to attack of depleted regions in reducing acids and direct dissolution of precipitates under oxidizing conditions. (auth)

• Research Organization: Cabot Corp., Kokomo, IN
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-000954
• OSTI ID: 4392804
• Journal Information: Corrosion, v. 29, no. 10, pp. 375-383, Journal Name: Corrosion, v. 29, no. 10, pp. 375-383; ISSN CORRA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*CHROMIUM ALLOYS-- ELECTROCHEMICAL CORROSION
*HYDROCHLORIC ACID-- CORROSIVE EFFECTS
*MOLYBDENUM ALLOYS-- ELECTROCHEMICAL CORROSION
*NICKEL BASE ALLOYS-- ELECTROCHEMICAL CORROSION
*SULFURIC ACID-- CORROSIVE EFFECTS
AGING
BOILING
CHEMICAL COMPOSITION
DISSOLUTION
ELECTROCHEMICAL CORROSION
HIGH TEMPERATURE
MICROSTRUCTURE
N50210* --Metals
Ceramics
& Other Materials--Metals & Alloys--Corrosion & Erosion & Surface Phenomena
OXIDATION
REDUCTION
SOLUTIONS
WATER CORROSIVE EFFECTS