Initiation and growth of cracks during cycling in an aged superduplex stainless steel

M BALBI; S HEREÑU; I PRORIOL-SERRE; J-B VOGT; A ARMAS; I ALVAREZ

KEY ENGINEERING MATERIALS

Trans Tech Publications

Lugar: Durnten-Zurich; Año: 2011 vol. 465 p. 411 - 414

1013-9826

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 that sometimes extend over several grains were found at approximately 45o of the tensile axis on ferrite grains. The origin of the microbands has been analyzed and correlated with the microcracks.