INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Análisis de la importancia del cierre prematuro sobre la fuerza impulsora para el avance de fisuras por fatiga en aceros austeníticos metaestables
Autor/es:
D.F. MARTELO; M.D. CHAPETTI
Lugar:
Santa Fe
Reunión:
Congreso; CONGRESO INTERNACIONAL DE METALURGIA Y MATERIALES SAM-CONAMET/IBEROMAT/MATERIA 2014; 2014
Institución organizadora:
Sociedad Argentina de Materiales (SAM)
Resumen:
In this paper we study the fatigue crack propagation behavior of an austenitic metastable stainless steel in the near threshold region. The steel used in this research is investigated in two different microstructural conditions: annealed and cold rolled. The fatigue crack propagation test were conducted using the procedure of ΔK decreasing constant R, and ΔK decreasing constant Kmax. The assessment of the fatigue crack propagation curves using the crack growth trajectory map proposed by Vasudevan and Sadananda point out that the mechanism that control the fatigue crack advance in this material change as a function of the level of ΔK applied. On the other side, the analysis of the fatigue crack propagation curves show that the behavior of this material cannot be explained entirely by the concepts of two driving forces. The contribution of the crack closure to the decrease in the fatigue crack growth rate is quantified using two methods, and the measurement of the crack opening load is done using the standard method proposed in the ASTM E647-08ε1and the ACRn2 method proposed by K. Donald et al. In basis of this last method and in the crack profiles, which are uncharacteristic in materials with austenite/martensite interface, it establishes that in this material the crack closure is induced by roughness. At the end of the paper, it is suggested an explanation of the load ratio effects using the two driving forces and having account the contribution of the crack closure.