High strength and ductile low density austenitic FeMnAlC steels: Simplex and alloys strengthened by nanoscale ordered carbides |
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Authors: | I Gutierrez-Urrutia D Raabe |
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Affiliation: | 1. Max-Planck-Institut für Eisenforschung, Max-Planck Str. 1, D-40237 Düsseldorf, Germanyi.gutierrez@mpie.de;3. Max-Planck-Institut für Eisenforschung, Max-Planck Str. 1, D-40237 Düsseldorf, Germany |
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Abstract: | AbstractWe introduce the alloy design concepts of high performance austenitic FeMnAlC steels, namely, Simplex and alloys strengthened by nanoscale ordered κ-carbides. Simplex steels are characterised by an outstanding strain hardening capacity at room temperature. This is attributed to the multiple stage strain hardening behaviour associated to dislocation substructure refinement and subsequent activation of deformation twinning, which leads to a steadily increase of the strain hardening. Al additions higher that 5 wt-% promote the precipitation of nanoscale L′12 ordered precipitates (so called κ-carbides) resulting in high strength (yield stress ~1·0 GPa) and ductile (elongation to fracture ~30%) steels. Novel insights into dislocation–particle interactions in a Fe–30·5Mn–8·0Al–1·2C (wt-%) steel strengthened by nanoscale κ-carbides are discussed. |
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Keywords: | Low density steels High Mn steels Microstructure control κ-carbides Strain hardening Deformation mechanisms |
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