Analysis of cyclic plastic response of nickel based IN738LC superalloy

0432561 - ÚFM 2015 RIV GB eng J - Článek v odborném periodiku
Petrenec, Martin - Polák, Jaroslav - Tobiáš, Jiří - Šmíd, Miroslav - Chlupová, Alice - Petráš, Roman
Analysis of cyclic plastic response of nickel based IN738LC superalloy.
International Journal of Fatigue. Roč. 65, AUG (2014), s. 44-50. ISSN 0142-1123. E-ISSN 1879-3452
Grant CEP: GA ČR(CZ) GAP204/11/1453
Institucionální podpora: RVO:68081723
Klíčová slova: IN738LC superalloy * Hysteresis loop analysis * Effective and internal stresses * Dislocation structure
Kód oboru RIV: JL - Únava materiálu a lomová mechanika
Impakt faktor: 2.275, rok: 2014

Cyclic strain controlled tests with blocks of stepwise increasing strain amplitudes were applied to cylindrical specimens of cast Inconel 738LC superalloy at 23 and 800 °C in laboratory atmosphere. Cyclic hardening/softening curves and shortened cyclic stress-strain curves were obtained at both temperatures. The hysteresis loops were analyzed using generalized statistical theory of the hysteresis loop. The second derivative of the half-loop exhibits three domains. The initial drop represents the plastic strain relaxation under decreasing effective stress and two peaks correspond to the probability density distribution of the internal critical stresses in matrix (gama phase) and gama’ phase respectively. Localized cyclic straining was identified using dislocation structure of PSBs and surface relief corresponding to PSMs. Weibull probability density function was fitted to individual peaks and effective stress component and probability density distributions of the internal critical stresses were quantitatively evaluated.
Trvalý link: http://hdl.handle.net/11104/0237015