Experimental studies on fundamental mechanisms leading to fatigue crack initiation

0381919 - ÚFM 2013 RIV RU eng C - Conference Paper (international conference)
Man, Jiří - Valtr, M. - Petrenec, Martin - Dluhoš, J. - Kuběna, Ivo - Obrtlík, Karel - Polák, Jaroslav
Experimental studies on fundamental mechanisms leading to fatigue crack initiation.
19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety. Kazan: Kazan Scientific Centre of the RAS, 2012 - (Klingbeil, D.; Vormwald, M.; Eulitz, G.), Paper No. 266. ISBN 978-5-905576-18-8.
[ECF 19 - European Conference on Fracture /19./. Kazan (RU), 26.08.2012-31.08.2012]
R&D Projects: GA ČR(CZ) GAP108/10/2371
Institutional support: RVO:68081723
Keywords : fatigue * 316L austenitic stainless steel * atomic force microscopy (AFM) * persistent slip band (PSB) * persistent slip marking (PSM) * extrusion * intrusion * crack initiation * point defects
Subject RIV: JL - Materials Fatigue, Friction Mechanics

Early stages of surface relief evolution of persistent slip markings (PSMs) in polycrystalline 316L austenitic stainless steel cycled with constant plastic strain amplitude at 93, 173 and 573 K were studied using atomic force microscopy (AFM) and high-resolution scanning electron microscopy (SEM–FEG). Qualitative and quantitative data on the morphology of PSMs, occurrence of extrusions and intrusions and the kinetics of extrusion growth are reported for all temperatures. In all cases PSMs start as surface extrusions which are later, depending on temperature, accompanied by formation of intrusions. This finding is discussed with respect to the point defect formation within areas of localized cyclic slip and especially to their mobility at different temperatures. Consequences of migration of respective point defects for surface relief formation and conditions for creation of fatigue crack embryos, i.e. sharp intrusions are highlighted.
Permanent Link: http://hdl.handle.net/11104/0212279