| 摘要 |
The steel slab comprises 0.035 to 0.050wt.% carbon, 2.9 to 3.3wt.% silicon, up to 0.032wt.% manganese, up to 0.015wt.% phosphorous, 0.011 to 0.017wt.% soluble aluminum, 0.008 to 0.012wt.% nitrogen, up to 0.007wt.% sulphur, 0.06 to 0.15wt.% nickel and/or chromium, up to 0.6wt.% copper, the weight ratio of Mn/S>20.0 and Cu/Mn>1.5, and the balance of iron and inevitable impurities. The magnetic steel sheet is produced by the processes of (1) hot rolling of the slab having the same composition as mentioned above as a starting material at 1,250 to 1,300deg.C, (2) the first cold rolling of hot rolled sheet to the thickness of 0.60 to 0.75mm, (3) decarburizing annealing at 820 to 840deg.C under wet hydrogen atmosphere, (4) the second cold rolling to final thickness, (5) intermediate annealing at 500 to 600deg.C, (6) coating of the annealing agent containing MgO as a main composition on the surface of annealed sheet, and (7) final high temperature annealing at 1,150 to 1,200deg.C during over 10hrs. The produced sheet by low temperature hot rolling and secondary recrystalliaztion stabilizing process is used for the iron core material of a transformer, an electromoter, a generator and electronic equipment etc.
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