Magnetic origin of chemical balance in alloyed Fe-Cr stainless steels: first-principles and Ising model study

TL;DR

This study reveals that magnetism significantly influences the chemical stability and properties of Fe-Cr stainless steels, with implications for microstructure tuning and corrosion resistance.

Contribution

It introduces a combined first-principles and Ising model approach to elucidate the magnetic origins of chemical balance in Fe-Cr alloys, highlighting the role of magnetic moments.

Findings

Magnetic moments of solutes affect alloy mixing energies.

Magnetic interactions influence chemical potentials in Fe-Cr alloys.

Results inform microstructure control and corrosion protection strategies.

Abstract

Iron-chromium forms the basis of most of the stainless steel grades in the markets. Recently new insights into the physical and chemical properties of Fe-Cr based alloys have been obtained. Some of the new results are quite unexpected and call for further investigations. The present study addresses the magnetic contribution in the atomic driving forces behind the chemical composition in Fe-Cr alloyed with Al, Ti, V, Mn, Co, Ni, and Mo. Using the ab initio exact muffin-tin orbitals method and an Ising-type spin model, it is found that the magnetic moment of the solute atom combined with the induced changes in the magnetic moments of the host atoms form the main framework in determining the mixing energy and chemical potentials of low-Cr Fe-Cr based alloys. The results obtained in the present work are related to tuning of the microstructure and corrosion protection of low-Cr steels.