Stainless steel optimization from quantum mechanical calculations

Alloy steel design has always faced a central problem: designing for a specific property very rarely produces a simultaneous significant improvement in other properties1,2. For instance, it is difficult to design a material that combines high values of two of the most important mechanical characteristics of metals, hardness and ductility. Here we use the most recent quantum theories of random alloys3 to address a similar problem in the design of austenitic stainless steels, namely, to combine high mechanical characteristics with good resistance against localized corrosion. We show that an optimal combination of these basic properties can be achieved in alloys within the compositional range of commercial stainless steels. We predict, first, that Fe58Cr18Ni24 alloys possess an intermediate hardness combined with improved ductility and excellent corrosion resistance, and, second, that osmium and iridium alloying additions will further improve the basic properties of this outstanding class of alloy steels.