| 摘要 |
PURPOSE:To produce a grain oriented silicon steel sheet having extremely high magnetic flux density and low iron loss by executing intermediate annealing in cold rolling under specific conditions in the stage of producing the grain oriented silicon steel sheet by hot rolling and cold rolling of silicon steel stock. CONSTITUTION:A silicon steel slab contg. 0.01-0.06% C, 2.0-4.0% Si, 0.03-0.11% 1 or 2 kinds of Se and S is hot rolled to a sheet material and thereafter the sheet material is subjected to homogenization annealing. Such material is subjected repeatedly to the cold rolling and intermediate annealing to yield the cold rolled steel sheet having the final sheet thickness. The interme diate annealing is executed by heating the sheet material up to 500-900 deg.C at a heating rate of >=5 deg.C/sec and holding the same at 900-1,100 deg.C. The mate rial is subjected to a high-temp. pulse treatment for a short period in the mid- way of the holding if necessary. The material is cooled at a cooling rate of >=5 deg.C/sec down to 900-500 deg.C after the holding and is then subjected to primary recrystallization annealing together with decarburization and final annealing to develop secondary crystal grains of the (100) <100> orientation. |
