Aufsatz in einer Fachzeitschrift
Surface damage evolution of engineering steel
Details zur Publikation
Autor(inn)en: | Besel, M.; Brückner-Foit, A. |
Publikationsjahr: | 2008 |
Zeitschrift: | Fatigue and Fracture of Engineering Materials and Structures |
Seitenbereich: | 885-891 |
Jahrgang/Band : | 31 |
Erste Seite: | 885 |
Letzte Seite: | 891 |
ISSN: | 8756-758X |
Zusammenfassung, 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.
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.
