Nippon Steel Corporation

Kensuke Mori

Yozo Suga

Tadashi Nakayama

Fumio Matsumoto

Hiromi Matsumoto

The present invention relates to a process for producing a grain-oriented silicon steel sheet or strip, wherein the crystals of the steel sheet or strip have an orientation of {110}&lt;001&gt; and, further, the steel is easily magnetized in the rolling direction. Since the slab-heating temperature for a grain-oriented silicon steel is considerably higher than that for low carbon steel grades, coarsening of the crystal grains is likely to occur during heating, and the coarse crystal grains are elongated during hot-rolling in the rolling direction and remain in the hot-rolled steel sheet as portions of the grain-oriented silicon steel strip or sheet, where secondary recrystallization becomes incomplete, or as so-called streaks. It is an object of the present invention to provide a novel hot-rolling technique capable of preventing the generation of streaks and capable of enhancing the magnetic flux density of the final product in terms of the B.sub.8 value even in a case where the tendency of streaks to form is small. The present invention is characterized in that during hot-rolling a silicon steel slap is subjected to at least one pass in which the axial lines of the top working roll and the bottom working roll are non parallel, and as a result of these working rolls being non parallel, the grain-oriented electromagnetic steel sheet or strip has no streaks and has a high magnetic flux density.

Growing community of inventors

Himeji, Japan

Kensuke Mori