Effect of crystal orientation and texture on fatigue crack evolution in high strength steel welds
2015 (engelsk)Inngår i: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 77, s. 95-104Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]
In the present study, electron backscattered diffraction is used to analyze the fatigue crack evolution in a high strength steel weld that was loaded cyclically in the plastic regime. Three prominent regions of a fatigue crack are investigated separately: crack tip, crack trajectory and crack initiation. Taylor and Schmid factors are mapped with respect to the defined loading matrix. Possible effective mechanisms are proposed based on the local plasticity properties like lattice rotation and misorientation. The analyses of the crack tip and trajectory regions show that although the critical resolved shear stresses in some regions are low, small deformation resistance of these regions can compromise the dislocation immobility and cause local fracture. It is shown that if the crack grows transgranularly, at least one side of the crack may show low lattice rotation or strain equivalent values, which indicates the relaxation of elastic stresses after fracture. The crack initiation is determined to be dominantly controlled by transcrystalline mechanism of initiation that takes place under plastic loading conditions. It is also shown that the secondary < 123 >11 (1) over bar type of slip systems were the most activated under such loading conditions. (C) 2015 Elsevier Ltd. All rights reserved.
sted, utgiver, år, opplag, sider
2015. Vol. 77, s. 95-104
Emneord [en]
Crystal orientation; Torsion; Fatigue; EBSD; Crack trajectory
HSV kategori
Forskningsprogram
TEKNIK, Produktions- och materialteknik
Identifikatorer
URN: urn:nbn:se:hv:diva-7613DOI: 10.1016/j.ijfatigue.2015.03.008ISI: 000354147300009Scopus ID: 2-s2.0-84925705593OAI: oai:DiVA.org:hv-7613DiVA, id: diva2:815925
Merknad
Available online 14 March 2015
2015-06-022015-05-302017-12-04bibliografisk kontrollert