Deakin University
Browse

The use of Fe-30% Ni and Fe-30% Ni-Nb alloys as model systems for studying the microstructural evolution during the hot deformation of austenite

journal contribution
posted on 2011-01-01, 00:00 authored by E Palmeire, Pavel CizekPavel Cizek, F Bai, R Poths, J Turner, B Wynne, W Rainforth
The development of physically-based models of microstructural evolution during thermomechanical processing of metallic materials requires knowledge of the internal state variable data, such as microstructure, texture, and dislocation substructure characteristics, over a range of processing conditions. This is a particular problem for steels, where transformation of the austenite to a variety of transformation products eradicates the hot deformed microstructure. This article reports on a model Fe-30wt% Ni-based alloy, which retains a stable austenitic structure at room temperature, and has, therefore, been used to model the development of austenite microstructure during hot deformation of conventional low carbon-manganese steels. It also provides an excellent model alloy system for microalloy additions. Evolution of the microstructure and crystallographic texture was characterized in detail using optical microscopy, X-ray diffraction (XRD), SEM, EBSD, and TEM. The dislocation substructure has been quantified as a function of crystallographic texture component for a variety of deformation conditions for the Fe-30% Ni-based alloy. An extension to this study, as the use of a microalloyed Fe-30% Ni-Nb alloy in which the strain induced precipitation mechanism was studied directly. The work has shown that precipitation can occur at a much finer scale and higher number density than hitherto considered, but that pipe diffusion leads to rapid coarsening. The implications of this for model development are discussed.

History

Journal

Materials and manufacturing processes

Volume

26

Pagination

127-131

Location

Philadelphia, Pa.

ISSN

1042-6914

eISSN

1532-2475

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2011, Taylor & Francis

Issue

1

Publisher

Taylor & Francis Inc.