To stably manufacture a high-strength non-grain-oriented electromagnetic steel sheet which has a high tensile strength TS of 60 kg/mm2 or higher, abrasion resistance and a superior magnetic property of a magnetic flux density B50 of 1.60 T or higher, by the use of on-line production system with the same easiness as in the manufacture of an ordinary electromagnetic steel sheet, for instance, in cold rolling.
This electromagnetic steel sheet includes, by mass%, 0.0040% or less C, 0.2-3.5% Si, 0.05-3.0% Mn, 0.30% or less P, 0.0040% or less S, 2.50% or less Al, 0.6-8.0% Cu, 0.0040% or less N, and a metallic phase consisting of Cu with diameters of 1.0 μm or less in the steel material. The manufacturing method is characterized by a heat treatment of holding it at a temperature of 450 to 720°C for 30 seconds or longer.
Jun Tsuruta
Hiroshi Kamematsu
Masaya Nishiyama