Influence of forging conditions on the fatigue mechanisms of low alloy steels: a 3D study
DOI:
https://doi.org/10.3221/IGF-ESIS.41.26Keywords:
Short cracks, 3D propagation, Crack closure, Synchrotron X-ray tomography, ForgingAbstract
The influence of forging conditions on the propagation of physically small fatigue cracks has been studied for two high strength steels. Two surface conditions were produced after the forging process. The subsurface microstructure of the materials has been characterized by EBSD. Small samples extracted from the original specimens were used to perform in situ fatigue tests monitored by high resolution synchrotron X-ray tomography. Fatigue cracks were initiated from an artificial defect (100 ?m wide x 50 ?m deep) introduced in the forging skin by laser machining. 3D images of the initiation and growth of those physically small fatigue cracks have been obtained. It was found that the presence of a shot-blasted skin containing a hardness and microstructure gradient influences the 3D crack shape during propagation in comparison with the materials without material properties gradient. The 3D crack shapes are rationalized in terms of crack closure effects induced by the forging processes, close to the surface.
Downloads
Downloads
Published
Issue
Section
Categories
License
Copyright
Authors are allowed to retain both the copyright and the publishing rights of their articles without restrictions.
Open Access Statement
Frattura ed Integrità Strutturale (Fracture and Structural Integrity, F&SI) is an open-access journal which means that all content is freely available without charge to the user or his/her institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without asking prior permission from the publisher or the author. This is in accordance with the DOAI definition of open access.
F&SI operates under the Creative Commons Licence Attribution 4.0 International (CC-BY 4.0). This allows to copy and redistribute the material in any medium or format, to remix, transform and build upon the material for any purpose, even commercially, but giving appropriate credit and providing a link to the license and indicating if changes were made.
How to Cite
