Short crack initiation during low-cycle fatigue in SAF 2507 Duplex stainless steel

MC MARINELLI; S DEGALLAIX; I ALVAREZ

Bexno

Conferencia; 10th Int Conf on the Mechanical Behavior of Materials; 2007

Korean Institute of Metals and Materials

In this work, the formation of fatigue cracks is considered as a nucleation process due to the development of a characteristic microstructure formed just beneath the specimen surface. Strain controlled cyclic tests were carried out at room temperature at total strain ranges of and 1.2% in flat specimens of SAF 2507 Duplex Stainless Steel (DSS). The results show that for this DSS, attotal strain range of 0.8%, the correlation between phases (Kurdjumov-Sacks crystallographic relation) plays an important role in the formation of microcracks. On the other hand, at1.2%, microcracks initiate in the ferritic phase and the K-S relation does not seem to affect the formation of the cracks.