High Cycle Fatigue of Metastable Austenitic Stainless Steels
Fargas Ribas, Gemma
Zapata Dederle, Ana Cristina
Anglada Gomila, Marcos Juan
Mateo García, Antonio Manuel
- Publisher: IOP PUBLISHING LTD.
:Enginyeria dels materials::Assaig de materials [Àrees temàtiques de la UPC] | Stainless steel | Materials--Testing | Acer inoxidable | Assaigs de materials
Metastable austenitic stainless steels are currently used in applications where severe
forming operations are required, such as automotive bodies, due to its excellent ductility. They
are also gaining interest for its combination of high strength and formability after forming. The
biggest disadvantage is the difficulty to predict the mechanical response, which depends
heavily on the amount of martensite formed. The martensitic transformation in metastable
stainless steels can be induced by plastic deformation at room temperature. In this research, the
martensitic transformation was provoked by means of torsion testing. Several torsion angles
were selected to achieve different percentages of martensite at the surface of the specimens.
The next step was to evaluate their effect on the fatigue life of the steel. Fatigue testing in the
high cycle regime was done at different levels of mean stress. As a conclusion, the presence of
martensite in the surface of the specimen led to an increase of the fatigue life when high mean
stress was imposed. By contrast, at lower values of mean stress, martensitic transformation has
no positive effect on the fatigue life.