Theoretical calculation of the finishing rolling elongation in alloying non-quenched and tempered steel

The finishing rolling elongation δ of the alloying non-quenched and tempered steel is calculated with the covalent electron number n_A of the strongest bond of the alloying phases and the interface electron density difference Δ_ρ of the phase interfaces. The calculations show that the elongation δ^α-Fe of the matrix α-Fe decreases with rolling refinement, the elongation δ^α-Fe-C-M of solid solution phases (M denotes alloying element) is inversely proportional to the covalent electron number n^α-Fe-C-M_A of the strongest bond, the elongation decrement Δ^{δα-Fe/α-Fe-C-M} caused by interface strengthening is directly proportional to the interface electron density difference Δρ^{α-Fe/α-Fe-C-M}, but the elongation decrements Δδ^α-Fe/MC^C₁ and Δδ^α-Fe/MC^C₂ caused by dispersion strengthening and precipitation strengthening respectively are directly proportional to the ratio of the electron density difference Δρ^α-Fe/MC^C₁ and Δρ^α-Fe/MC^C₂ of the strengthening interfaces to Δρ^{α-Fe/α-Fe-C} of the basic interface α-Fe/α-Fe-C. Therefore, the finishing rolling elongation of the alloying non-quenched and tempered steel is considered to be subtracting all the elongation decrements of solution strengthening, interface strengthening, dispersion strengthening and precipitation strengthening from the elongation of the refined α-Fe matrix. The calculation formulas in this paper are integrated with the proposed ones of σ_S, σ_b and of α_K delivered in another paper, the finishing rolling mechanical properties can be achieved and the calculated results agree well with the measured ones.

Theoretical calculation of the finishing rolling elongation in alloying non-quenched and tempered steel

The finishing rolling elongation δ of the alloying non-quenched and tempered steel is calculated with the covalent electron number n A of the strongest bond of the alloying phases and the interface electron density difference △ρ of the phase interfaces. The calculations show that the elongation δα-Fe of the matrix α-Fe decreases with rolling refinement, the elongation δα-Fe-C-M of solid solution phases (M denotes alloying element) is inversely proportional to the covalent electron number nAα-Fe-C-M of the strongest bond, the elongation decrement △δα-Fe/α-Fe-C-M caused by interface strengthening is directly proportional to the interface electron density difference △ρα-Fe/α-Fe-C-M, but the elongation decrements △δα-Fe/MCC1 and△δα-Fe-C/MCC2 caused by dispersion strengthening and precipitation strengthening respectively are directly proportional to the ratio of the electron density difference △ρα-Fe/MCC1 and △ρα-Fe-C/MCC2 of the strengthening interfaces to △ρα-Fe/α-Fe-C of the basic interface α-Fe/α-Fe-C. Therefore, the finishing rolling elongation of the alloying non-quenched and tempered steel is considered to be subtracting all the elongation decrements of solution strengthening, interface strengthening, dispersion strengthening and precipitation strengthening from the elongation of the refined α-Fe matrix. The calculation formulas in this paper are integrated with the proposed ones of σS, σb and of αK delivered in another paper, the finishing rolling mechanical properties can be achieved and the calculated results agree well with the measured ones.