Effect of initial microstructure on surface relief and fatigue crack initiation in AISI 410 ferritic‐martensitic steel. Issue 1 (19th June 2018)

• Record Type: Journal Article
• Authors: Batista, M.N.; Marinelli, M.C.; Alvarez‐Armas, I.
• Is Part Of: Fatigue & fracture of engineering materials & structures. Volume 42:Issue 1(2019)
• Page Start: 61
• Page End: 68
• Publication Date: 2018-06-19
• Subjects: EBSD -- ferritic‐martensitic steel -- low cycle fatigue -- microcrack nucleation -- microstructure; Materials -- Fatigue -- Periodicals; Fracture mechanics -- Periodicals; 620.1123
• DOI: 10.1111/ffe.12868
• Languages: English
• ISSNs: 8756-758X

Abstract

Abstract: This work is focused on the effect of the initial tempered‐lath microstructure on the surface relief and nucleation of microstructurally short fatigue cracks developed during low‐cycle fatigue tests of the ferritic‐martensitic AISI 410 steel. Transmission and scanning electron microscopy as well as electron back‐scattered diffraction were used to study the surface‐damage evolution in smooth, cylindrical, notched specimens. Results from the electron back‐scattered diffraction analysis broaden the understanding of the processes of nucleation of microstructurally short fatigue cracks in the initial tempered‐lath microstructure of AISI 410 ferritic‐martensitic steels. Results prove that during fatigue, microcracks nucleate mainly at high‐angle boundaries represented by block subunit interfaces formed in this tempered microstructure. Besides, the progress of fatigue cycling causes the reorientation of the {112} <111> systems to a direction more favourable to slip, giving rise to the formation of extrusions within the blocks and consequently the formation of microcracks.