High-temperature tensile properties of nano-oxide dispersion strengthened ferritic steels produced by mechanical alloying and spark plasma sintering

Oxide-dispersion strengthened (ODS) ferritic steels were produced by mechanical alloying and subsequent spark plasma sintering. Very fast heating rates were used to minimize porosity when controlling grain size and precipitation of dispersoids within a compacted material. Sintering cycles performed at 1373 K (1100 C) induced heterogeneous, but fine grain size distribution and high density of nano-oxides. Yield strengths at room temperature and at 923 K (650 C) are 975 MPa and 298 MPa, respectively. Furthermore, high-temperature ductility is much increased: total strain of 28 pct at 923 K (650 C). (authors)