Characterisation of Duplex Stainless Steels Sintered by Field-Assisted Hot Pressing (FAHP)

摘要

Duplex stainless steels (DSS) can be obtained by powder metallurgy (PM) routes. In this study, duplex stainless steels are processed by a new PM route involving the mixing of ferritic and austenitic powders, into a designed proportion, and the sintering by Field-Assisted Hot Pressing (FAHP). Thus, a duplex microstructure is achieved and a diffusion interface, modifying the mechanical properties, appears at grain boundaries as a result of the diffusion of nickel from austenite to ferrite. This third phase is smaller than that reported in the literature where conventional PM routes were applied. In this work, the effect of the initial morphology/size of the raw powders and the beneficial effect of using a Field Assisted Sintering Technique (FAST) on the final microstructure and mechanical properties of DSS is assessed.