Texture development during cold rolling of Fe–Cr–Ni alloy-experiments and simulations

Abstract

In the present work, evolution of microstructure and crystallographic texture during cold rolling of two phase Fe–Cr–Ni alloy was investigated. Fe–Cr–Ni alloy (in initially solution annealed condition) was uni-directionally cold rolled in a laboratory rolling mill to different thickness reductions. Scanning electron microscopy was used to observe the changes in microstructure, while X-ray diffraction was used to investigate changes in crystallographic texture of austenite and ferrite (through changes in orientation distribution function). Crystallographic texture was also simulated using different crystal plasticity models (Full constraint Taylor, relaxed constraint Taylor (lath and pancake) and co-deformation Visco Plastic Self Consistent (VPSC)). With the increase in plastic deformation, there were morphological as well as crystallographic changes in the microstructure. Strong α-fibre (RD//〈1 1 0〉) texture was developed in ferrite, while brass ({1 1 0}〈1 1 2〉) and Goss ({1 1 0}〈0 0 1〉) was dominant in austenite after 80% cold rolling. The formation of brass type texture after deformation has been attributed to the formation of shear bands and presence of strong crystallographic texture in the initial solution annealed material. Both Taylor as well as VPSC models could not capture the changes in texture with deformation accurately. For ferrite: γ-fibre (ND//〈1 1 1〉) and for austenite: Cu ({1 1 2}〈1 1 1〉) component was always present in the simulated textures. Possible reason for this could be the pining effect of interface boundaries and non-incorporation of non-crystallographic shear banding in the Taylor and VPSC models.

Keywords:

• Fe–Cr–Ni alloy
• EBSD
• microstructural characterisation
• texture
• Taylor model
• VPSC model
• shear bands

Acknowledgements

The authors would like to thank The Director, VNIT Nagpur for providing the necessary facilities and constant encouragement to publish this paper. Thanks are also due to Prof. I. Samajdar, Convener, ‘National Facility of Texture & OIM (a DST-IRPHA facility)’, IIT Bombay for EBSD and bulk texture measurements. One of the authors, RKK, wishes to acknowledge the Science and Engineering Research Board (SERB) for financial assistance to carry out this work. RKK also wishes to acknowledge Networking Resource Centre for Materials (NRCM), IISc, Bangalore for financial assistance.