| 摘要 |
PURPOSE:To manufacture the title electrical thick sheet having high magnetic flux density in a low magnetic field and having less difference in magnetic characteristics in its sheet thickness by limiting the component of a steel material, subjecting it to hot rolling and thereafter successively executing the regulation of crystal grains and dehydrogenation heat treatment to the steel material. CONSTITUTION:A slab or a cast slab constituted of, by weight, <=0.01% C, <=0.02% Si, <=0.20 Mn, <=0.015% P, <=0.010% S, <=0.05% Cr, <=0.01% Mo, <=0.01% Cu, 0.005 to 0.03% Ti, 0.005 to 0.01% Ca, <=0.005% Al, <=0.004% N, <=0.005% O, <=0.0002% H and the balance substantial iron is heated to 1150 to 1300 deg.C and is rolled including one or more times of rolling pass having rolling shape ratio A expressed by the Formula at >=900 deg.C final temp. In >=50mm sheet thickness, 600 to 750 deg.C dehydrogenation heat treatment and, at need, 750 to 950 deg.C annealing or 910 to 1000 deg.C normalizing are executed, and in 20 to <50mm sheet thickness, 750 to 950 deg.C annealing or 910 to 1000 deg.C normalizing is executed. By this method, the electrical thick sheet of >=20mm sheet thickness having the magnetic characteristics of >=0.8 tesla magnetic flux density in 80A/m magnetic field can be obtd. |
