| 摘要 |
PURPOSE:To increase magnetic flux density and to reduce iron loss by subjecting a steel in which respective contents of C, Si, Al, Sb, and Sn are specified to hot rolling and then to cold rolling twice while performing process annealing between the cold rolling stages under respectively prescribed conditions. CONSTITUTION:A steel having a composition consisting of, by weight, 0.005-0.02% C, <=1.5% Si or Si+Al, <=1% Mn, <=0.2% P, <=0.1% Sb and/or Sn, and the balance Fe is refined. This steel is hot-rolled under the condition of 600-700 deg.C rolling finishing temp. and >=500 deg.C coiling temp. Subsequently, the resulting hot rolled steel strip is held at a temp. of the A3 transformation point or below for 30sec-15min and cooled from the Ar3 transformation point to the Ar1 transformation point at 2-10 deg.C/sec cooling rate, or, the above hot rolled steel strip is held at a temp. between Ar1 and (Ar1+50 deg.C) for 5-30sec and cooled from the Ar1 transformation point to 100 deg.C at >=10 deg.C/sec cooling rate. |
