On measurement of retained austenite in multiphase TRIP steels — results of blind round robin test involving six different techniques

Abstract

International audienceThe present paper reports the results of a blind round robin test dedicated to the measurement of the retained austenite content of different TRIP assisted multiphase steels. Various surface and volume techniques, i.e. light microscopy, X-ray diffraction, electron backscattered diffraction (EBSD), magnetic saturation, thermal diffusivity and laser ultrasonics, were used by different partners. The compiled results show a quite large variability of the estimated retained austenite content, particularly for well established techniques, such as X-ray diffraction (XRD) and magnetisation. On the other hand, emerging techniques like EBSD, thermal diffusivity and laser ultrasonics warrant further investigations

<i>In situ</i> Observations of Transformation Behavior upon Heating for a 1.5Mn-1.5Si-0.2C Steel -Comparison between Neutron Diffraction, XRD, EBSD and Dilatometry-

“…Hence, the characterization of the retained austenite is very important and many studies have been performed so far. [13][14][15][16][17] In most of such works, a specimen was interruptedly quenched during material processing in order to freeze its microstructure at a certain elevated temperature. It is, however, difficult to freeze high temperature microstructure completely and hence not easy to track microstructural evolution continuously at the same observation position of a specimen.…”

Strain-Induced Martensitic Transformation and Texture Evolution in Cold-Rolled Co–Cr Alloys

“…Although these problems can be minimized by optimizing the measurement conditions and surface preparation, one should always be careful with these issues. A similar problem has been pointed out in the case of the determination of meta-stable residual austenite fraction in bainitic/martensitic steels [17].…”

A microstructural investigation on deformation mechanisms of Fe–18Cr–12Mn–0.05C metastable austenitic steels containing different amounts of nitrogen

“…In comparison to the TEM study conducted by Lee et al [12,15], the EBSD method is able to show the evolution of different phases in a more quantitative manner. Although different characterization techniques of optical microscopy, magnetic measurements, thermal diffusivity, laser ultrasonics, X-ray diffraction (XRD) and EBSD may be used for the phase analysis, it has been shown that there is a quite large variability of the estimated phase content, particularly for the well-established techniques such as XRD and magnetization [21,22]. The EBSD technique is able to successfully determine the volume fraction of the microstructural constituents and also to measure the local orientations and orientation gradients within individual grains of the composing constituents.…”