High intensity electromagnetic steel plate and method of manufacturing the same

Production of a high-strength electromagnetic steel sheet with a tensile strength as high as 500 MPa or greater, exhibiting not only wear resistance but also magnetic characteristics excelling in magnetic flux density and iron loss. There is provided a process for producing a high-strength electromagnetic steel sheet containing, by mass, 0.060% or less C, 0.2-6.5% Si, 0.05-3.0% Mn, 0.30% or less P, 0.040% or less S or Se, 2.50% or less Al and 0.020% or less N, optionally further containing at least one member selected from among 0.001-30.0% Cu and 0.03-8.0% Nb wherein a worked structure remains in the interior of the steel sheet, which process includes enlarging the average crystal grain diameter (D, [mu]m) of the sheet just before the step of forming the worked structure finally remaining in the interior of the steel sheet to such an extent satisfying the relationship D=20 [mu]m, preferably in the final working step, after application of a strain, avoiding such a heat treatment as that the worked structure is eliminated. Moreover, there is provided an electromagnetic steel sheet produced by the process.