| 摘要 |
<p>A high-strength cold rolled steel sheet and a high-strength plated steel sheet which have excellent geomagnetism shielding characteristics, i.e. a high relative magnetic permeability in a DC magnetic field of around 0.3 oersted, a method of manufacturing the same, and an explosion-proof band using such steel sheets for a TV cathode-ray tube or an outer magnetic shielding material using such steel sheets. The method of manufacturing these steel sheets comprises deoxidizing very low carbon steel which has not more than 0.0060 % of C, and which has been strengthened by solid solution with Si and Mn but not by a deposition strengthening, in such a manner that A1 does not substantially remain in the steel, or adding B to the steel for restraining the deposition of A1N when deoxidization of the steel with A1 is carried out, subjecting the resultant steel to finishing rolling at 750°-980 °C, subjecting the steel to 60-90 % cold rolling, and then annealing the steel in continuous annealing equipment or in-line annealing type continuous molten zinc plating equipment in a temperature range of not lower than 750 °C and not higher than Ac3 point so as to set the ferrite crystal grain size in its metallographic structure to 10-200 νm.</p> |
