Nonlinear Deformation of Fe, FeSi and FeCrSi with BCC Structure Under Pressure

The model and the theory of nonlinear deformation for BCC substitutional and interstitial ternary alloy are built on the basis of the statistical moment method. Numerical calculations are performed for Fe, FeSi and FeCrSi in the range of temperature from 0 to 500 K, in the range of pressure from 0 to 9.8 GPa, in the range of interstitial atom concentration from 0 to 5% and in the range of substitutional atom concentration from 0 to 10%. The maximum real stress and the elastic deformation limit both decrease with increasing the interstitial atom concentration, increase with increasing the substitutional atom concentration and increase with increasing the temperature. The maximum real stress increases and the elastic deformation limit decreases when the pressure increases. Some calculated results on nonlinear deformation of Fe obtained by SMM have been compared with the experimental data and have some very good concordance. Many calculated numerical results on nonlinear deformation of FeSi and FeCrSi are new and predictive, experimentally oriented.