| 摘要 |
Cube-on-edge oriented silicon-iron stock for magnetic uses, containing e.g. 2-3.5% Si, 0.04-0.15% Mn and e.g. 0.025% C with balance Fe and impurities, is produced by hot reducing the stock e.g. from 2100 to 2550 DEG F., removing the scales, e.g. by pickling after annealing at 1675 or 1800 DEG F., cold rolling to final gauge, and subjecting it to a final anneal consisting of a primary grain growth stage e.g. at 1000-1800 DEG F. and a secondary grain growth stage e.g. at 1700-2200 DEG F, wherein S, Se or a compound thereof is provided as a grain growth inhibitor to diffuse into the grain boundaries of the stock during the primary grain growth stage to favour growth of cube-on-edge oriented nuclei during the secondary grain growth stage. Preferably the S content of the stock is raised by 0.0005-0.003% when its temperature has reached 1800 DEG F. in the final anneal. Annealing is preferably effected in dry H2 containing at least 700 ppm. H2S, or other S-containing gas such as SO2 or SF6. Prior to the final anneal, the stock may be decarburized e.g. at 1500 DEG F. in wet H2 or the S compound may be contained in a decarburizing atmosphere during the final anneal to form a layer of FeS on the surface of the stock. Annealing may be effected using a vacuum or an inert gas atmosphere e.g. N2, with or without H2, and with the stock as stacked sheets or loose wound coils using a refractory annealing separator, e.g. of MgO, Al2O3 and/or CaO or TiO2, containing 1/2 -10% elemental S (equivalent to 0.0025-0.05% S based on the weight of stock); alternatively, 0.1-1% FeS based on the weight of stock may be added to the separator. |
