| 摘要 |
<p>In order to provide a non-oriented magnetic steel sheet that has no surface defects and exhibits high flux density, low iron loss and excellent recycling characteristics, a slab with a composition consisting of 0.005 mass% or less of C, 1.5-4.5 mass% of Si, 0.005 mass% or less of Al, 0.01-0.10 mass% of Mn, 0.0010-0.0050 mass% of Ca, 0.0030 mass% or less of S and 0.0030 mass% or less of N, with Ca/S >= 0.80 and the remainder being Fe and unavoidable impurities, is heated at a temperature of 1050-1150°C, is subjected to hot rolling so that the temperature after the completion of the finish rolling is 800-900°C, is rolled up at a temperature of 500-650°C, is subjected to hot-plate annealing at a temperature between 950°C and the temperature at which the slab was heated, and after being subjected to hot or cold rolling, is further subjected to finish annealing at a temperature of 950°C or higher in an atmosphere containing at least 10 vol% hydrogen and having a dew point of -20°C or lower.</p> |
