Gaseous environment effects on fatigue behaviour of metals

Abstract

Premature and catastrophic fatigue failures have stimulated the re-evaluation of concepts used in the design and selection of structural materials. Fatigue is an important mechanical property that must be understood before designers can predict the behaviour of the material in engineering applications. In this paper, the metallurgical aspects of fatigue crack initiation and propagation are reviewed. The models and mechanisms associated with environmental effects on fatigue are discussed and special emphasis is placed on the importance of gaseous environments on fatigue behaviour. Although several mechanisms have been proposed for corrosion fatigue most of these are specific to a metal-environment system and cannot be extended to include a wide variety of systems. Because of this lack of universal applicability a general lack of agreement will continue to exist among researchers unless careful and minute attention is paid to the experimental and system details of any fatigue study.