| 摘要 |
<p>PURPOSE:To prevent oxidation of grain boundary and to reduce rolling load at the time of cold-rolling by hot-rolling the specific composition of high silicon steel at the specific temp. range and coiling at the specific temp. CONSTITUTION:Soaking treatment is executed to the steel composed of 0.05-0.25wt.% C, 0.5-3.0% Si, 0.5-3.0% Mn and the balance of Fe with inevitable impurities. In hot-rolling, rolling reduction is executed at >=70% in the temp. range of Ar1 to Ar3, and austenitic vol. ratio at the outlet side in the finish roll stands is made 20-70%. Successively, this is coiled at 300-650 deg.C. During coiling gamma-alpha transformation is promoted and heat-returning caused by the transformation after coiling can be made little and the oxidation of the grain boundary can be prevented. In the above steel composition if necessary, one or more kinds of 0.02-0.10% Nb, 0.01-0.10% Ti and 0.03-0.10% P, are contained.</p> |
