MODELLING THE ATMOSPHERIC PITTING CORROSION OF ALUMINIUM ALLOYS

摘要

Atmospheric pitting corrosion of aluminium alloys is very important to the aircraft industry as pitting of critical aircraft components can significantly reduce their fatigue life. Much published work has addressed pitting corrosion in aluminium alloys and many models predicting the propagation of pits have been developed. This modelling has in most cases been empirical, with extreme value statistics analysis of pit depths and pit depth related to time of exposure using power laws. However, these models don't always take into account the nature of pit propagation observed during atmospheric exposure. This paper presents a new method of predicting atmospheric pitting corrosion using mechanistically based modelling. The concepts behind the modelling will be discussed along with the parameters required to perform the calculations. Finally the results returned by the model will be compared to pit depth distributions obtained from trials.