Properties of vacuum sintered duplex stainless steels

This work presents the possibility of obtaining duplex stainless steels through powder metallurgy technology starting from austenitic X2CrNiMo 17-2-2, martensitic X6Cr13 powders by controlled addition of alloying elements, such as chromium, nickel, molybdenum and copper in the right quantity to obtain the chemical composition of the structure similar to biphasic one. In the studies behind the preparation of mixes, Schaffler's diagram was taken into consideration. Prepared mixes of powders have been compacted at 800 MPa and sintered in a vacuum furnace with argon backfilling at 1260 °C for 1 h; after sintering rapid cooling has been applied in N2, with an average cooling rate of 650 °C/min. Produced duplex stainless steels has been studied by SEM with EDS a light optical microscopy (LOM) and X-ray analysis to determine obtained structures. Mechanical properties such as tensile strength, impact energy, hardness and wear rate were evaluated.