The effect of microstructure Low cycle fatigue in some single phase and biphasic stainless steels
Jacques Stolarz, Saint-Etienne, France
ABSTRACT The influence of microstructural parameters on low cycle fatigue damage in some single phase and biphasic stainless steels has been studied. In a single phase austenitic steel, the fatigue life increase with decreasing grain size is attributed to the positive effect of microstructural barriers in the bulk. In a metastable austenitic steel, the grain size of the initial microstructure has a combined influence on the volume fraction of martensite formed during cyclic loading and on the fatigue life. In this case, the beneficial effect of grain refinement is indirect because all cracks grow in the martensite. Possible damage patterns in a cluster of grains with different properties are discussed on the example of a duplex austenitic-ferritic steel. It is demonstrated that the propagation behaviour of short cracks related to the resistance of microstructural barriers in the bulk, has a decisive influence on the fatigue life. The macroscopic fatigue resistance is thus controlled by damage events at the microstructure size scale.
Publication Source: Materialprüfung, ISSN: 0025-5300
Issue: 2004-6, pp -
Publisher: Carl Hanser Verlag München
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