Corrosion can be defined as the reaction of a material with its environment. It is a major factor governing the design and operation of all types of plant and equipment. The control of corrosion - the materials selection, protection, corrosion monitoring, measurement and prediction - presents a considerable challenge to engineers and, in spite of our best efforts, the annual costs of corrosion damage and corrosion-related service failures run into many millions of pounds. Such failures are difficult to prevent due to the complex nature of many corrosion mechanisms and their interaction with residual and mechanical stresses in service. These mechanisms quite often give rise to non-uniform forms of corrosion which can result in severe local attack leading to failure. This paper gives an introductory guide to the main types of aqueous corrosion of metals and alloys. Localised forms such as pitting, crevice corrosion, intergranular attack and leaching are explained in terms of the basic anodic and cathodic reactions, differential aeration and design. The influence of stresses is also considered with reference to an outline of stress corrosion cracking and corrosion fatigue.
展开▼
