MISORIENTATION BETWEEN AUSTENITE AND <I>\sigma</I>-PHASE IN DUPLEX STAINLESS STEEL

Abstract

Duplex steels are very interesting stainless steels. Their name originates from their special austenitic-ferritic structure. This tissue is due to the high alloying and low carbon content. During heat treatment, several phase transformation and precipitation processes take place. Electron back scattering diffraction is a relatively new investigation method, by which the individual grain orientation can be determined in the scanning electron microscope. The greatest advantage of this method is its speed: it is possible to determine a grain orientation even within 0.1 second. Therefore, in a relatively short time a large amount of data can be collected, and can be statistically evaluated. This paper reports a research work, in which SAF-2507 type duplex stainless steel samples were heat-treated isothermally, and the misorientation between the austenite and \sigma-phase was calculated.