Short Crack Initiation during Low-Cycle Fatigue in SAF 2507 Duplex Stainless Steel
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 εt = 0.8 and 1.2% in flat specimens of SAF 2507 Duplex Stainless Steel (DSS). The results show that for this DSS, at εt = 0.8%, the correlation between phases (Kurdjumov-Sacks crystallographic relation) plays an important role in the formation of microcracks. On the other hand, at εt = 1.2%, microcracks initiate in the ferritic phase and the K-S relation does not seem to affect the formation of the cracks.
S.W. Nam, Y.W. Chang, S.B. Lee and N.J. Kim
M.C. Marinelli et al., "Short Crack Initiation during Low-Cycle Fatigue in SAF 2507 Duplex Stainless Steel", Key Engineering Materials, Vols. 345-346, pp. 343-346, 2007