PROCEDURE FOR PRODUCTION OF STRIPS OF ELECTRO-TECHNICAL ISOTROPIC STEEL WITH IMPROVED PROPERTIES Russian patent published in 2011 - IPC C21D8/12 

FIELD: metallurgy.

SUBSTANCE: to obtain uniformity of magnetic and mechanical properties along length of electro-technical isotropic steel it is melted, subjected or not to out-of-furnace treatment, and cast. Before hot rolling slabs are heated at low temperature, prepared; then hot-rolled strips are normalised, etched, cold-rolled and subjected to combined decarbonisation-re-crystallisation annealing or to crystallisation annealing. Also, velocity of strip transfer in a line of the normalisation unit (NU) is determined by formula: V(L)=V₀-k·(ΔT_opt-ΔT(L)), where: V(L) is current velocity of strip at normalisation, L is coordinate along length of strip, m/s; V₀ is regulated velocity of strip at annealing, m/s; ΔT(L) is cooling degree of hot-rolled strip at a collecting roller-table °C equal to ΔT(L)=T_er(L)-T_wnd(L), where T_er(L), T_wnd(L) - is temperature of end of rolling and winding correspondingly; ΔT_opt is an optimal value of parametre ΔT at velocity of strip in the line of the NU equal to V₀,°C; k is coefficient of proportionality determined by means of calculations or experimentally for each group of dimension type and chemical composition of strips, m/(c°C).

EFFECT: reduced non-uniformity of magnetic and mechanical properties in strips of electro-technical isotropic steel.

1 ex, 1 dwg