0024832 - ÚFM 2006 RIV GB eng J - Journal Article
Polák, Jaroslav - Zezulka, Petr
Short crack growth and fatigue life in austenitic-ferritic duplex stainless steel.
[Růst krátkých trhlin a únavová životnost austeniticko-feritické duplexní oceli.]
Fatigue and Fracture of Engineering Materials and Structures. 28 2005, č. 10 (2005), s. 923-935. ISSN 8756-758X. E-ISSN 1460-2695
R&D Projects: GA ČR(CZ) GA106/01/0376
Institutional research plan: CEZ:AV0Z20410507
Keywords : crack growth * crack initiation * duplex steel
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 0.673, year: 2004

The kinetics of short crack growth has been studied in austenitic-ferritic 2205 duplex stainless steel. Smooth cylindrical specimens and specimens with shallow notch were subjected to constant plastic strain amplitude loading. The crack growth was studied in notched specimens. The notch area has been mechanically and electrolytically polished to facilitate the observation of crack initiation and growth. The initiated cracks were observed in SEM. The crack growth was studied using long distance QUESTAR optical microscope equipped with high-resolution camera. In constant plastic strain amplitude loading the micro-cracks were initiated and their growth kinetics has been studied. The characteristic features of the crack growth at different plastic strain amplitudes were recorded. Two approaches to analyse the crack growth rates were adopted. The comparison of the prediction of the fatigue life using the plastic strain dependent crack growth rate was compared with Manson-Coffin law and the relation between parameters of this law and parameters of the short crack growth law were established.

Kinetika růstu krátkých trhlin byla studována v austeniticko-feritické duplexní nerezové oceli. Hladké vzorky a vzorky s mělkým vrubem byly zatěžovány s konstantní amplitudou plastické deformace. Růst trhlin byl studován na vrubovaných vzorcích. Oblast vrubu byla mechanicky a elektrolyticky leštěna. Iniciované trhliny byly pozorovány v rastrovacím elektronovém mikroskopu. Růst trhlin byl sledován pomocí mikroskopu QUESTAR s dlouhou ohniskovou vzdáleností,který byl spojen s vysokorozlišovací kamerou. Kinetika trhlin byla sledována v režimu konstantní amplitudy plastické deformace. Byly použity dvě koncepce pro analýzzu růstu trhlin. Predikce únavové životnosti z měření rychlostí trhlin byla srovnána s predikcí podle Manson-Coffinova zákona a byly nalezeny relace mezi parametry vystupujícími v obou zákonech.
Permanent Link: http://hdl.handle.net/11104/0115315