ABSTRACT
In many industrial situations metallic materials are subjected to a large temperature gradient and hence there is a large heat flux through the material. Typical examples are the alloy tubes in heat exchangers and boilers in the power industry. The temperatures of operation are usually high and therefore the metal is undergoing slow oxidation. Nearly all basic studies of corrosion are undertaken in isothermal conditions and there are very few data to indicate the effect of an imposed thermal gradient. There has been one attempt to model the effect of a heat flux on oxidation and this shows that under certain conditions “catastrophic” oxidation can occur, i.e. the oxidation rate increases with oxide thickness.
During a fundamental study of the effects of a heat flux on the oxidation of pure metals, the authors have developed the thermodynamics of the process in a more complete form than in earlier work. The results of an experimental study of the process are reported here.
