In view of their high chemical resistance and good mechanical properties, duplex stainless steels are gaining increasing importance in the handling of media causing simultaneous corrosion and wear. Due to their two-phase microstructure, their resistance to hydroabrasive wear is higher than that of austenitic steels.

This paper describes measures designed to further increase the wear resistance of duplex stainless steels. Among these are precipitation-hardening by special heat treatment, but also alloying techniques such as the precipitation of special carbides. In this context, a new-developed material is described, which is characterised by a ferritic-austenitic matrix with embedded special carbides and exhibits high corrosion resistance in heavily acid, chloride-containing media, while its wear resistance is virtually identical to that of common white iron grades.

The influence of the above measures on the corrosion resistance of duplex stainless steels is illustrated on the basis of results from exposure tests and electrochemical measurements.