| 摘要 |
PURPOSE:To manufacture the grain-oriented silicon steel sheet with low iron loss at a low cost by performing the decarburization annealing and finish annealing of the silicon steel strip having a specific composition consisting of Si, Al, N and Fe in a specific atmosphere after cold rolling. CONSTITUTION:The silicon steel strip having the composition consisting of, by weight, 0.8-4.8% Si, 0.012-0.05% acid-soluble Al, <=0.01% N, and the balance substantially Fe with inevitable impurities is cold rolled to the final thickness in one or two or more cold rolling including the intermediate annealing. This cold-rolled steel sheet is decarburization annealed, and the inhibitor is reinforced through the nitrogen increasing process. Then, the separating agent for annealing which is mainly composed of MgO is coated and laminated on this steel sheet to perform the finish annealing. In this manufacturing method, the degree of oxidation (PH2O/P-H2) is set to 0.01-0.15 to prevent the formation of Fe oxide such as Fe2SiO4 in the layer of the oxide. The surface roughness of the glass film is reduced by adding >=5% H2 in the atmosphere for the finish annealing. |
