The chemical composition of duplex stainless steels can be optimized in function of in-service conditions. The purpose of this paper is to present an economical duplex stainless steel containing 23% Cr and 4% Ni additions (1–3%) in order to improve its machinability properties.

The paper presents phase diagrams, mechanical properties, corrosion resistance properties, in-service experiences as well as machinability data of the grades. It is also confirmed that the molybdenum-free duplex alloy can be strengthened by rich copper phase precipitations, so that corrosion erosion resistance is improved.