Oxidation of Iron‐Nickel Alloys: II . Electron Diffraction at High Temperature

Abstract

The oxidation of iron‐nickel alloys of 30%, 41%, and 78% Ni content has been studied at temperatures of 600°, 700°, 800°, and 900°C by the electron diffraction technique. A special furnace was developed for the electron diffraction instrument for these experiments.Usually more than one oxide was present on the alloy at these elevated temperatures. Unlike the conclusion drawn from exclusively room temperature observations, the predominant oxide on the 30% and 41% Ni alloys was the ferrite ( or ) rather than . At 700° and 900° both and exist on the 78% alloy. (This alloy contains 3.8% Mo.) The presence of above its melting point and where it exerts considerable vapor pressure is difficult to explain.In some cases the lattice spacings of the alloy structure are carried over into the first formed oxide film. With subsequent growth the spacings achieve the normal (x‐ray) values for the oxide.