This article provides information on fracture toughness and fatigue crack growth of structural steels. It describes fatigue life behavior in terms of unnotched fatigue limits, notch effects, axial strain-life fatigue, and mean stress effects. The article analyzes the mechanisms of corrosion fatigue crack initiation and prevention of corrosion fatigue. It presents case histories of fatigue failure of various steel components. The article reviews the failure of coiled tubing in a drilling application and the failure of coiled tubing due to hydrogen sulfide exposure, with examples.

This article reviews general trends in the cyclic response for representative commercial alloys to establish the spectrum of cyclic properties attainable through microstructural alteration. Individual alloy classes are examined in detail to assess the understanding of relationships between microstructure and fatigue resistance. These alloys classes include ferritic-pearlitic alloys, martensitic alloys, maraging steels, and metastable austenitic alloys. The article also discusses the role of internal defects and selective surface processing in influencing fatigue performance.