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Deformation behaviour of duplex stainless steel during industrial hot rolling
Author(s) -
Duprez Lode,
De Cooman Bruno C.,
Akdut Nuri
Publication year - 2002
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200200024
Subject(s) - materials science , electron backscatter diffraction , metallurgy , austenite , ferrite (magnet) , microstructure , indentation hardness , composite material
Industrially processed duplex stainless steel sheet was investigated after the reheating, the roughing mill and the finishing rolling. Light optical microscopy revealed that the cast structure that existed before rolling was removed and changed into a banded microstructure. During the process, the ferrite‐austenite volume fraction ratio changed from 72 %a + 28 %γ to 48 %α + 52 %γ. The microhardness was measured for both phases after each process step. Texture measurements were executed by means of the electron backscattering diffraction technique (EBSD). These measurements revealed that extensive static recrystallisation of the austenite occurred during the roughing but that recrystallisation was inhibited during the finishing. Transmission electron microscopy (TEM) on the finish rolled material indicated that the ferrite softened efficiently by extended dynamic recovery. The dislocations in ferrite grains with rotated cube orientation were often found to be straight screw dislocations which were inclined 55° to the surface of the sheet. The importance of the partitioning of the alloying elements and the strain partitioning on the deformation behaviour is highlighted.