FAILURE OF structural components subjected to an aggressive environment may occur under static or fluctuating loads. Failure under static loads is caused by general corrosion or by stress-corrosion cracking. Failure under fluctuating loads in an aggressive environment is caused by the initiation and the propagation of corrosion fatigue cracks. The following sections present the use of fracture mechanics concepts to study stress corrosion cracking, corrosion fatigue crack initiation, and corrosion fatigue crack propagation.