| 摘要 |
<p>PURPOSE:To obtain a high-magnetic flux density grain oriented silicon steel sheet having a low iron loss by rolling a steel sheet consisting of a polycrystalline material which contains a specific ratio of Si and is controlled in the content of C, N and S to a specific thickness at which a prescribed quantity of tension exists and specifying the secondary recrystal grains thereof. CONSTITUTION:A hot rolled sheet steel of a silicon steel stock having a prescribed compsn. is subjected adequately to annealing and cold rolling, then to an adequate heat treatment and cooling prior to the final cold rolling. The steel sheet consisting of the polycrystalline material which contains 2.3-3.8% Si and is limited to respectively <=0.0020% C, N and S as impurities is thereby obtd. The residual stress consisting of 0.20-1.2kg/mm<2> tension exists in the resulted steel sheet and the sheet thickness thereof is 0.15-0.25mm, B10>=1.89T; in addition, the crystal grains having <=2mm diameter equiv. to a circle exist at 15-70% of the entire part and the average value ND of the distances between the nearest grains of such <=2mm crystal grains is in the range of ND=2.0-8.0mm. The grain oriented silicon steel sheet having low iron loss of <=0.88W/kg W17/50 is thus obtd.</p> |
