Influence of temperature (Topic 11035)

Generally, corrosion rates like all chemical reaction rates will increase with increasing temperature. But other parameters, like the solubility of O2, will contribute and make the picture a bit more complicated. The pH-area where the aluminium oxide is stable, is dependent on temperature and will be narrower and moved towards lower pH values at elevated temperatures. This will only be important at very high temperatures and will have no practical importance in most cases.

However the effect on pitting may be more important. Elevated temperatures will stimulate pitting attacks and hence increase the weight loss, but the pit depth may be reduced.

One special effect of temperature is that the corrosion potential is changed. This means that if one part of a structure is constantly cold and one is constantly warm a so called thermo-galvanic attack may occur.