SHORT CRACK INITIATION DURING LOW-CYCLE FATIGUE IN UNS S32750 DUPLEX STAINLESS STEEL PLATE

M.G. MOSCATO; M. C. MARINELLI; S. DEGALLAIX; I. ALVAREZ-ARMAS

Italia

Conferencia; Duplex2007; 2007

Associazione italiana di Metallurgia

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 Äåtotal =0.8, 1.0 and 1.2% in flat specimens of rolling UNS S32750 Duplex Stainless Steel plates. The results show a strong influence of the dislocation structure formed just beneath the free surface en the formation of deformation induced martensitic transformation, microbands in grains and deformation bands crossing phases.   KEYWORDS Low-cycle fatigue, crack initiation, microstructure, shear bands, martensitic transformation KEYWORDS Low-cycle fatigue, crack initiation, microstructure, shear bands, martensitic transformation