Ab initio development of a high-strength corrosion-resistant austenitic steel

Abstract

A new austenitic steel alloyed with carbon + nitrogen is developed based on ab initio calculations of the electronic structure, which were carried out using the local density functional theory, and on experimental studies by means of conduction electron spin resonance. It is shown that alloying of CrMn austenite with carbon + nitrogen increases the concentration of conduction electrons and assists their more homogeneous spatial distribution, which results in short-range atomic ordering and, consequently, in a higher thermodynamic stability of iron-based face-centered cubic solid solutions. The developed CrMnCN steel is characterized by a yield and ultimate strength of 600 and 1000 MPa, respectively, in combination with an extremely high fracture energy. The notch-impact toughness exceeds 400 J. The resistance to impact wear is comparable with that of Hadfield steel. Corrosive properties are in some corrosive media similar to those of austenitic Cr18Ni10 steel. Possible applications of the developed steel are discussed.