| 摘要 |
1411094 Coated steel NIPPON STEEL CORP 25 Sept 1972 [27 Sept 1971] 44208/72 Heading B2E [Also in Division C7] A grain oriented silicon steel sheet is provided with a surface film to improve iron loss and magnetostriction characteristics by application of a solution composed of 4-16% colloidal silica, 3-24% aluminium phosphate and 0.2- 4.5% of at least one compound selected from chromic anhydride and a chromate and baking the resulting coating at above 350‹C. The solution may be applied by dipping or spraying to the surface of the steel sheet which may be covered with a glossy film formed during the high temperature finishing annealing of the sheet or with a phosphate film. Boric acid may be added to the coating solution in amount 0.18 to 3.51%, and non-colloidal silica powder may be added in amount 0.045 to 1.43%.
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