STUDIES ON THE OXIDATION OF ZIRCONIUM WITH AIR

Journal Article · Sat Mar 01 04:00:00 EST 1958 · Nippon Kinzoku Gakkaishi (Japan)

OSTI ID:4268401

Maekawa, T; Hata, T; Tachihara, Y

The reaction kinetics of the Kroll-processed reactorgrade zirconium under 1 atm. of air was studied over the temperature range of 650 to 900 deg C. An analysis of the rate data showed that the cubic rate law was applicable in the initial stage of oxidation. However, a breakdown of the oxide film was observed at 800 and 850 C, and then the oxidation proceeded in accordance with the linear rate law. A plot of the logarithms of the cubic rate law constants against the reciprocal of absolute temperature gave a straight line, and the activation energy of 48,400 cal/mol was calculated. Chemical analysis was used for the determination of the amount of nitrogen absorbed during oxidation of zirconium in air. The contents of absorbed nitrogen in the oxide layer increased with oxidation time and temperature, but no existence of a ZrN phase was found by x-ray analysis. The experimental formula of absorption of nitrogen during the oxidation of zirconium in air, W /sup 3/2 = kt (where W: weight of absorbed nitrogen, k: constant, t: time), is suggested. And the activation energy of 82,400 cal/mole was calculated for absorption of nitrogen during the reaction of zirconium with air, over the temperature range of 700 to 850 deg C. It is concluded that the rate-controlling step of the oxidation of zirconium is the process of diffusion of oxygen ion in the oxide film. (auth)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-13-017026
• OSTI ID: 4268401
• Journal Information: Nippon Kinzoku Gakkaishi (Japan), Journal Name: Nippon Kinzoku Gakkaishi (Japan) Vol. Vol: 22; ISSN NIKGA
• Country of Publication: Country unknown/Code not available
• Language: Japanese

Related Subjects

ADSORPTION
AIR
ANIONS
DIFFUSION
EXCITATION
FILMS
HIGH TEMPERATURE
LATTICES
METALLURGY AND CERAMICS
NITROGEN
NUMERICALS
OXIDATION
QUALITATIVE ANALYSIS
REACTION KINETICS
X RADIATION
ZIRCONIUM
ZIRCONIUM NITRIDES
ZIRCONIUM OXIDES