Speaker
Description
Austenite-to-ferrite phase transformation in steels has been largely investigated during the last decades as it plays an important role in controlling the mechanical properties of steels. Despite tremendous efforts in understanding the mechanisms controlling ferrite formation, the role of substitutional elements during ferrite
Validation of the developed models requires an experimental study of the effect of both composition and temperature on growth kinetics. Combinatorial materials coupled with high throughput structural characterization provides a new alternative to improve the understanding of microstructures evolution.
The aim of this contribution is to present a complete combinatorial methodology to accelerate the investigation of austenite-ferrite growth kinetics dependency on substitutional composition in alloy steels.
The essence of the methodology is to fabricate materials with macroscopic composition gradients, and to perform time- and space-resolved high energy X-ray diffraction experiments to gather the austenite-to-ferrite phase transformation kinetics in many points of the compositional space.
Diffusion couples with solute gradients were generated using hot compression between different ternary Fe-C-X alloys (where X: Cr,Ni,Mn,Mo,Si), followed by high temperature diffusion treatment and hot rolling to generate and extend the gradients. Ferrite growth kinetics during austenite-ferrite phase transformation at inter-critical temperatures were gathered within the substitutional gradients using high-energy X-ray diffraction experiments. In-situ kinetic maps were gathered for many points of the compositional space and for different sets of temperatures. The obtained dataset are used to validate and optimize models describing solute drag effect on ferrite growth kinetics.
| Speaker Country | France |
|---|