Corrosion of stressed components

Many engineering components operate under the combined influence of service stresses and deleterious environment. For better life prediction and to prevent failures, it is necessary to understand the mechanical behaviour of materials under conjoint action of stress and environment. Depending upon the metal-stress-environment system, the operating mechanism that would affect the life of the component may differ. Some of these mechanisms are discussed in this paper. Typically, the life limiting factor of engineering materials in corrosive environments have been identified as stress corrosion cracking, damage in components due to the presence of hydrogen, corrosion fatigue and fretting corrosion. In this paper, each of these phenomena has been discussed with respect to their mechanisms, methods to quantify the damage and ways to prevent or control them. Developments in fracture mechanics have been used as an effective tool in assessing the materials resistance to fracture. Application offracture mechanics techniques to predict the fracture behaviour of materials in aggressive environments has been discussed along with the conventional techniques.