ISSN:
1573-4889
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Very rapid oxide film growth and severe intergranular penetrating oxidation of unstressed Zircaloy specimens has been observed infused eutectic mixtures of NaNO3-KNO3-NaCl and NaNO3-KNO3-KBr at 300°C. Studies of the oxide films produced have shown that the accelerated film growth rate is associated with a change in oxide crystallite morphology, which affects the ionic transport process, coupled with a large decrease in the electronic resistivity of the oxide. The onset of intergranular penetration is determined by the development of porosity in the surface layer; no gross cracking or spalling of the oxide occurs until a late stage in the deterioration of the specimen. The penetrating intergranular oxidation does not stifle itself because an open channel is maintained along the plane of the original grain boundary surface. Severe attack in air or steam can be caused by minute deposits on specimens of NO′3-Cl′ salts which are molten at the oxidation temperature. Examples of such attack in-reactor have been identified.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00604043
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