Journal article
Surface damage evolution of engineering steel



Publication Details
Authors:
Besel, M.; Brückner-Foit, A.
Publication year:
2008
Journal:
Fatigue and Fracture of Engineering Materials and Structures
Pages range:
885-891
Volume number:
31
Start page:
885
End page:
891
ISSN:
8756-758X

Abstract
The surface damage evolution of ordinary low carbon steel under mechanical fatigue loading was observed using a long-distance microscope. Fatigue cracks initiated at pits, sulfide inclusions and in the soft ferrite phase. Damage evolution was not only pronounced by the initiation of well-defined cracks. Areas of high plastic activity interspersed with microcracks exist. Coalescence of propagating well-defined cracks with these areas of high plastic activity shows clearly the contribution of such plastified areas to the damage accumulation. Therefore, well-known damage parameters such as line counts (i.e. maximum crack length) are unsuitable to describe the damage evolution. In this paper, a new damage parameter is defined based on the observation that cracks and plastified areas appear as dark regions. It is shown that this parameter satisfies the basic conditions for a damage parameter. It is used to evaluate the damage accumulation quantitatively based on surface observations even for complex damage patterns.

Last updated on 2019-01-11 at 16:04