SHEET FROM NON-ORIENTED ELECTRICAL STEEL WHICH IS PERFECT FROM THE STANDPOINT OF REDUCTION OF LOSSES IN CORE AND METHOD OF MANUFACTURE OF SUCH SHEET Russian patent published in 2007 - IPC C22C38/00 C21D9/46 H01F1/16 

FIELD: non-oriented electrical steels used for manufacture of magnetic cores for motors and similar equipment; methods of manufacture of such sheets.

SUBSTANCE: sheet is made from steel containing the following constituents, mass-%: carbon, up to 0.01; silicon, from 0.1 to 7.0; aluminum, from 0.,1 to 3.0; manganese, from 0.1 to 2.0; rare-earth metals, from 0.0003 to 0.05; titanium, up to 0.02; sulfur, up to 0.005 and nitrogen, up to 0.005; the remainder being iron and unavoidable admixtures, provided the following equation is satisfied: log({Ti]x[N]) - 1.9xlog([Al]x[N]) + 1.84>0, where [Ti]is content of titanium, mass-%; [N] is content of nitrogen, mass-% and [Al] is content of aluminum, mass-%. Density of distribution of inclusions contained in said steel sheet at volume equivalent diameter lesser than 100 nm is 10x10¹⁰ [1/mm³] or lesser. Method of manufacture of steel sheet includes stage of holding the sheet at temperature of from 1200 to 1300°C for a minute and more. Steel has large grains which is sufficient for reduction of losses in core even at low-temperature annealing and during short period of time after stamping.

EFFECT: enhanced efficiency.

5 cl, 5 dwg, 2 tbl