Tensile yield behavior and precipitation strengthening mechanism in Super304H steel

Tensile yield behaviors of the solution- and aging-treated Super304H austenitic steel have been investigated at temperatures from 300 to 923 K. The results showed that the contribution to yield stress from precipitation strengthening of Cu-rich phases is 17-23%. The higher thermal activation volume and energy imply an interaction between dislocation and Cu-rich precipitates. The precipitation strengthening mainly arises from coherency strain and partially from stacking fault strengthening. The calculated shear stress from precipitation strengthening agrees reasonably with the experimental result.