Mechanical characteristics and corrosion resistance properties of different PM duplex stainless steels compositions

摘要

The production of casting duplex stainless steels have been well known since the '50s, but PM duplex are developing just these years; mostly they are studied in universities and research centres and only few quantities are commercialised. Different studies starting from different kind of powders are trying to develop what wrought biphasic alloys represent in the field of casting products: higher mechanical properties and corrosion resistance than austenitic grades, especially a superior resistance in SCC conditions. Exstensive studies have been carried out on PM stainless steels in general and in particular on AISI 316L, but few works are present on austeno-ferritic structures. Duplex stainless steels can provide high mechanical properties and corrosion resistance and so their use can be extended to "critical" applications. In this work it is examined the possibilty of obtaining duplex stainless steels through PM technology starting from martensitic and austenitic powders (410L and 316L grade) by simple addition of alloying elements, such as chromium, nichel, molibdenum,, manganese, etc. The mechanical properties and corrosion resistance are herewith examined