| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a high strength high permeability steel sheet for a cathode ray tube band which has stably high yield stress. <P>SOLUTION: The high strength high permeability steel sheet for a cathode-ray tube band has a chemical composition comprising, by mass, 0.003 to 0.010% C, 0.5 to 1.0% Si, 1.0 to 2.0% Mn, 0.04 to 0.15% P, ≤0.02% S, ≤0.030% Al and ≤0.004% N, and the balance Fe with inevitable impurities, and satisfying C×Mn×P≥2.5×10<SP>-4</SP>. In the steel sheet, the ferrite crystal grain size is 10 to 100 μm, the yield stress is ≥300 N/mm<SP>2</SP>, and preferably, the relative permeability in a d.c. magnetic field of 0.35 Oe is ≥400. The steel sheet can be produced by controlling a hot rolling coiling temperature to 600 to 700°C, and properly combining a cold rolling ratio and an annealing temperature in the range of 750 to 900°C. Zn-based or Al-based plating may be applied. Alternatively, skin-pass rolling of ≤1.5% can be performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
