Chemical Characteristics of Water Indluencing Corrosion

Abstract

Metals immersed in water tend to corrode because of their thermodynamic instability. Natural waters contain dissolved solids and gases and sometimes colloidal matter; all these may affect the corrosive properties of the water in relation to the metals with which it is contact. The effect may be either one of stimulation or one of supp-ression and it may affect the cathodic or the anodic react-ion. Some metals form a natural protective film in water and the corrosiveness of water to these metals depends on whether or not the dissolved material it contains assists in the maintenance of a self-healing film. The metals most commonly used for water systems are cast iron and mild steel. The concepts presented here are a review of the information available in the literature on the corrosive behviour of different waters towards cast and mild steel.