Room temperature tensile properties of Fe-19wt.%Cr alloys precipitation hardened by the intermetallic compound NiAl

摘要: Abstract Aged Fe-19wt.%Cr alloys containing stoichiometric additions of nickel and aluminium at the 2 4 at.% levels were investigated using tensile tests transmission electron microscopy. These are strengthened by precipitation intermetallic compound NiAl. Their mechanical properties tentatively explained in terms existing precipitation-hardening theories. Up to peak strength, precipitates sheared dislocations. For these conditions it is shown that difference between elastic constant matrix NiAl order hardening made major contributions strengthening. overaged particles bypassed dislocation loops. most a linear work-hardening rate was observed small plastic strains. This behaviour related effect long-range back stresses. The slightly overestimated when theories derived from continuum mechanics used. At larger strains stress-strain curves found be parabolic. In this regime short-range interactions. Its amplitude compared with value obtained Ashby model. Finally, that, after suitable thermomechanical aging treatments, ferritic stainless steels can exhibit an attractive strength-ductility combination.