| 摘要 |
<p>PURPOSE:To provide the method for producing a nonoriented silicon steel sheet used as the iron core material of electric equipment. CONSTITUTION:In the method for producing a nonoriented silicon steel sheet in which a slab contg., by weight, <=2.50% Si and <=1.00% Al so as to satisfy <=2.50% (Si+2Al), and the balance Fe with inevitable impurities in steel is subjected to hot rolling into a hot rolled sheet, its sheet thickness is regulated to a final one by one time cold rolling stage, and finish annealing is executed, the coiling temp. after the hot rolling is regulated to the Ar3 point or above, it is held to the Ar3 point or above for 20sec to 3hr after the coiling, and subsequently, the strip coil is cooled in such a manner that the average cooling rate from the Ar3 point to the Ar1 point is regulated to <=50 deg.C/sec to transform its phase into an alpha phase, which is subjected to cold rolling at 60 to 90% draft. In this way, the magnetic flux density of the nonoriented silicon steel can be improved, and the material low in iron loss can be obtd.</p> |
