Nanoindentation Characterization of Mechanical Properties of σ Phase in Super Duplex Stainless Steel

To predict the effect of σ phase precipitation on mechanical properties of 00Cr25Ni7Mo4N super duplex stainless steel, the intermetallics σ phase was characterized by nanoindentation after slow cooling, and the microstructure was observed. The results show that the volume fraction of σ phase in the steel was 36.7%, and the nanoindentation hardness of the σ phase was in the range of 14.0-17.1 GPa with a mean value of 15.7 GPa; the modulus of elasticity was in the range of 262-380 GPa with a mean value of 317 GPa. In addition, the substrate-effect on results could be removed.