| 摘要 |
The use of coarse sand particles having an average size of 0.5-10 mm in the sealing of the lower end portion of an inner cover, which is arranged in a box annealing furnace, at the final annealing, in the production of grain-oriented silicon steel sheets, can maintain the interior of the inner cover at a low dew point atmosphere. It can also substantially prevent the exfoliation of forsterite insulating film from the coiled steel sheet surface at the upper and lower edge portions of the coiled steel sheet. |
