The yield strength of iron alloys and the contribution of lattice bond

Iron alloys with elements of the group III–VIII of the Periodic Table as like as steels were annealed for production of different grain sizes in the dualphase microstructure. The yield strength values and the grain diameters served for a Hall-Petch analysis. During the tear-off of dislocations and slip at the yield point also the lattice bindings were changed for a short time. The yield strength should give an evidence to this. Quantities, which express the lattice bond, are the caloric quantities of the lattice destruction process, the activation energy of self-diffusion and the elastic moduli. It can be shown that the total alloying content determines the content of pearlite, and this the inner friction stress σi. The tendency of the elements to form pearlite will be clear by including the electronegativity (after L. Pauling). The slope in the Hall-Petch relationship ky correlates with the Young modulus and the activation energy of volume diffusion for grain growth and expresses the connection with the lattice bond.