Fatigue crack growth of a metastable austenitic stainless steel

MARTELO, D.F.; MATEO, A.M.; CHAPETTI, M.D.

INTERNATIONAL JOURNAL OF FATIGUE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2015 vol. 80 p. 406 - 416

0142-1123

The fatigue crack growth behavior of an austenitic metastable stainless steel AISI 301LN in the Parisregion is investigated in this work. The fatigue crack growth rate curves are evaluated in terms ofdifferent parameters such as the range of stress intensity factor DK, the effective stress intensity factorDKeff, and the two driving force parameter proposed by Kujawski K⁄.The finite element method is used to calculate the stress intensity factor of the specimens used in thisinvestigation. The new stress intensity factor solution has been proved to be an alternative to explaincontradictory results found in the literature.Fatigue crack propagation tests have been carried out on thin sheets with two different microstructuralconditions and different load ratios. The influence of microstructural and mechanical variables has beenanalyzed using different mechanisms proposed in the literature. The influence of the compressiveresidual stress induced by the martensitic transformation is determined by using a model based onthe proposal of McMeeking et al. The analyses demonstrate the necessity of including Kmax as a truedriving force for the fatigue crack growth. A combined parameter is proposed to explain the effects ofdifferent variables on the fatigue crack growth rate curves. It is found that along with residual stresses,the microcracks and microvoids are other factor affecting the fatigue crack growth rate in the steelstudied.