Fatigue crack propagation in a ductile superalloy at room temperature and extensive cyclic plastic flow
2015 (English)In: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 80, 40-49 p.Article in journal (Refereed) Published
Fatigue crack propagation experiments under both force and displacement control have been performed on the wrought superalloy Haynes 230 at room temperature, using a single edge notched specimen. The force controlled tests are nominally elastic, and the displacement controlled tests have nominally large plastic hysteresis at the beginning of the tests, but saturates towards linear elastic conditions as the crack grows. As some tests are in the large scale yielding regime, a non-linear fracture mechanics approach is used to correlate crack growth rates versus the fracture parameter Delta J. It is shown that crack closure must be accounted for, to correctly model the crack growth seen in all the tests in a unified manner. For the force controlled small scale yielding tests the Newman crack closure model was used. The Newman equation is however not valid for large nominal cyclic plasticity, instead the crack closure in the displacement controlled tests is extracted from the test data. A good agreement between all tests is shown, when closure is accounted for and effective values of Delta J are used.
Place, publisher, year, edition, pages
ELSEVIER SCI LTD , 2015. Vol. 80, 40-49 p.
Fatigue crack propagation; Haynes 230; Large scale yielding; Cyclic J-integral or Delta J; Crack closure
IdentifiersURN: urn:nbn:se:liu:diva-122045DOI: 10.1016/j.ijfatigue.2015.04.006ISI: 000360596500005OAI: oai:DiVA.org:liu-122045DiVA: diva2:885495
Funding Agencies|Siemens Industrial Turbomachinery AB, Finspang, Sweden2015-12-182015-10-192016-04-21