Equation for predicting the Corrosivity of Natural Fresh Waters to Aluminium

Abstract

NATURAL fresh waters thicken the protective surface oxide film of aluminium and most such waters can be handled in aluminium tanks, pipes and equipment, provided the wall thickness is adequate. There is no general corrosion or thinning of the aluminium and if corrosion does occur it takes the form of pitting. It has been shown that the rate of penetration by pitting follows a cube root law¹. The law predicts that to double the wall thickness will increase the time to penetration eight-fold; hence the importance of wall thickness in designing aluminium equipment to handle water is evident.