| 摘要 |
PURPOSE:To stably decrease the iron loss of a grain oriented silicon steel sheet even in the production line of a factory in a method for decreasing the iron loss of said steel sheet by the radiation of plasma flames by suppressing the fluctuation of the distance between the tips of nozzles for radiating the plasma flames and the surface of the steel sheet. CONSTITUTION:The fluctuation of the distance between the tips of the nozzles for radiating the plasma flames and the surface of the steel sheet is kept at <=3mm in the stage of continuously radiating the plasma flames on the grain oriented silicon steel sheet subjected to finish annealing. The satisfactory effect of decreasing the iron loss is thus stably obtd. A method for radiating the plasma flames while exerting either of tensile stress or bending stress or the composite stress thereof to the steel sheet in the rolling direction thereof is effective to suppress the variation of the above-mentioned fluctuation to <=3mm. Another equally preferable method is to maintain the specified distance between the steel sheet and the nozzles by detecting the distance between the steel sheet and the tips of the nozzles by a sensor such as laser, feeding back the signals thereof and moving the nozzles to adequate positions. |
