Short crack growth during cycling in an aged superduplex stainless steel

.I. ALVAREZ-ARMAS; M. BALBI ; S. HEREÑÚ ; A. F. ARMAS

Brno

Conferencia; Sixth International Conference on Materials Structure & Micromechanics of Fracture; 2010

The kinetics of short crack growth during cycling has been studied in a superduplex stainless steel in aged condition. After few cycles, slip lines appear distributed in both phases but the preferred phase for microcrack nucleation is the ferrite. Contrary to the exponential behavior observed in the as-received material, the growth rate of microcracks in aged condition follows a rather linear law. Internal dislocation structures were studied in the near surface region; microbands were found formed at approximately 45º of the tensile axis on ferrite grains that extends over several grains. The origin of the microbands has been analyzed and correlated with the microcracks