| 摘要 |
An alloy has less stable oxides, e.g. nickel oxide, chromium oxide, and iron oxide on a surface (FIG. 1 ). The material has specific reaction elements such as titanium and aluminum in a relatively low concentration throughout the alloy. At an elevated temperature, the surface of the alloy is subject to a fluid which reduces the nickel, chromium, and iron oxides and the aluminum or titanium adjacent the surface reduces components of the fluid (FIG. 2 ). The alloy is maintained at the elevated temperature in the presence of the fluid until a barrier film of the specific reactive elements is formed. In one embodiment, the working fluid is a gaseous fluid of hydrogen or an inert gas with water vapor. The hydrogen of the water vapor reduces the less stable oxides and the oxygen oxidizes the specific reaction elements. In another embodiment, the working fluid is a liquid metal other than lithium which carries oxygen. The liquid metal reduces the less stable oxides and provides oxygen for oxidizing the specific reactive elements. In a third embodiment, the working fluid is liquid lithium, which reduces both the less stable oxides and the oxides of the specific reactive elements. The lithium contains nitrogen or carbon which reacts with the least specific elements to form nitrides or carbides.
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