Void formation during oxidation of the ODS alloy MA 6000

Autor: H. Fattori, J. L. González-carrasco, V. Guttmann
Rok vydání: 1995
Předmět:
Zdroj: Metallurgical and Materials Transactions A. 26:915-924
ISSN: 1543-1940
1073-5623
DOI: 10.1007/bf02649088
Popis: The present work deals with investigations on the subsurface void formation in the oxide dispersion strengthened (ODS) alloy MA 6000. The effect that results from oxidation has been analyzed for stress-free and stressed samples exposed to creep deformation up to a maximum exposure time of about 11,000 hours at 1050 ‡C. Additional tests in the stress-free condition have been performed at 1150 ‡C for up to 1300 hours. The depth of voiding increases with time following a parabolic rate law, and in the long-term range, it reaches about 2 mm at 1050 ‡C. For the stressed state during long-term exposure, the penetration was slightly deeper than for the stress-free state, and large voids were elongated perpendicular to the stress axis. For long exposure times at 1050 ‡C, the area of voids was about 1 to 2 pct of the total void-affected zone, and the maximum void diameter could reach about 25.0 Μm. A void-free zone, the width of which increased with time, formed beneath the scale. Among the mechanisms considered to explain the void formation, vacancy injection resulting from outward diffusion of mainly Cr seems the most consistent.
Databáze: OpenAIRE
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