6. Creep associated with oxidation and/or fatigue phenomena

6.1 Effect of oxidizing atmosphere on creep behaviour

The two main oxidation phenomena are :

• the creation of a protective layer by the formation of a more or less stable compound (generally oxides) with one or more elements from the atmosphere; if the compound is desquamated, the cross-section of the material subjected to stress decreases, the stress exerted increases and therefore the rate of deformation increases; but if the compound is stable and forms a continuous film on the surface of the material, the rate of deformation decreases because part...