Fatigue Behaviors in Duplex Stainless Steel Studied Using In-Situ SEM-EBSD Method
2014 (English)In: Procedia Materials Science, ISSN 2211-8128, Vol. 3, 1748-1753 p.Article in journal (Refereed) Published
Austenite and ferrite in duplex stainless steels have different physical and mechanical properties. They can behave different during cyclic loading. To understand the fatigue behaviors of these two phases, an in-situ SEM/EBSD fatigue test has been performed. Flat specimens made from the specimens of pre-fatigue tested with three point bending were cyclically loaded in a scanning electron microscope via a compact test rig. By in situ/ex situ SEM/EBSD examination, slip activities and propagation of the fatigue cracks have been studied. Microstructures along the path of the fatigue crack were characterized. The different phase properties seem to lead to certain difference in the slip activity and formation of PSBs. Inhomogeneous slip activities and local strain concentrations were also found, which developed with increasing number of load cycles. Crack propagation behaviors in grain and cross the grain or phase boundaries have been discussed. Crack deflection occurs at the phase boundaries, but crack branching occurs mainly in the grains due to the dislocation slip. In-situ SEM/EBSD fatigue test confirms that crack propagation deflection and formation of crack branches can significantly reduce the crack propagation rate.
Place, publisher, year, edition, pages
Elsevier, 2014. Vol. 3, 1748-1753 p.
Fatigue, Fatigue crack propagation, in-situ SEM/EBSD, Crack branching, Crack deflection
IdentifiersURN: urn:nbn:se:liu:diva-111059DOI: 10.1016/j.mspro.2014.06.282OAI: oai:DiVA.org:liu-111059DiVA: diva2:752942
20th European Conference on Fracture (ECF20), 30th of June - 4th of July, Trondheim, Norway