K-S RELATIONSHIP IDENTIFICATION TECHNIQUE BY EBSD

M.C. MARINELLI; M. MOSCATO; J.W. SIGNORELLI; A.E. BARTALI; I. ALVAREZ-ARMAS

KEY ENGINEERING MATERIALS

Trans Tech Publications, Switzerland

Año: 2011 vol. 465 p. 415 - 418

1013-9826

Duplex stainless steels (DSSs) are two-phase alloys (á/ã) which combine the properties of austenitic and ferritic stainless steels. In DSS, ferrite and austenite constitute a composite  material consisting of similar amounts of these ductile phases. DSS solidifies from the liquid phase to a completely ferritic structure (á). Austenite grains (ã) appear by solid phase transformation as cooling proceeds leading to an interconnected austenite-ferrite structure. Both phases are related to near Kurdjumov-Sachs (K-S) crystallographic relationships: {111}ã//{110}á and [110]ã//[111]á. This efficiency of the coupling between phases plays a key role in the plastic deformation. Some authors [1, 2] have reported that in the case of special orientation relationship between the two phases, dislocation sources can be activated in the ferrite at the grain boundaries due to the local stress concentration caused by the dislocation pile-ups in the austenite. Often, these relations were experimentally studied using transmission electron microscopy [3, 4], but this technique allows only to study small areas in specimens which are ultra-thin foils. Following this idea, the existence of the K- S relationship in a larger area of material in flat specimens of hot- and cold-rolled plates UNS S32750 DSS plates was analysed. This task was accomplished using a combination of EBSD analysis and SEM observations of slip markings on the specimens.