IFIR   05409
INSTITUTO DE FISICA DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Nucleation and propagation mechanisms of microstructurally short cracks in duplex stainless steels: Experimental characterization and modeling
Autor/es:
M.C. MARINELLI
Lugar:
Freiberg
Reunión:
Conferencia; Networkmeeting Alexander von Humboldt Foundation; 2010
Institución organizadora:
Alexander von Humboldt
Resumen:
Duplex stainless steels (DSS) are finding increased applications as structural materials because of higher strength, superior resistance to stress corrosion cracking and better weldability. The excellent combination of these properties is obtained from balanced amount of ferrite and austenite in the microstructure. However, this grade of steel embrittles (aged condition) when exposed in the temperature range of 280-500 °C limiting its application to temperatures below 280 °C. More than 80% of the low cycle fatigue lifetime of engineering alloys consists of the nucleation and propagation of surface short cracks. Owing to their strong interactions with microstructural features, e.g. grain and phase boundaries, they exhibit substantially non-uniform propagation kinetics as compared with the growth rate of long cracks, which can be well described using a power-law function of the range of the stress-intensity factor. In the present project, interactions between the crystallographic misorientation of grain and phase boundaries and microcracks in austeno-ferritic duplex stainless steels in the normalized and in the aged thermal conditions will be analyzed and quantified by means of fatigue experiments in combination with the electron backscattered diffraction technique (EBSD). In the second part, it is expected to simulate the crack advance mainly in the aged materials, which would be capable of considering these real microstructural barriers.