| 摘要 |
PROBLEM TO BE SOLVED: To produce a grain-oriented silicon steel sheet extremely high in magnetic flux density by using a slab having specified components and executing low friction rolling in which the friction coefficient and draft are specified at the time of finish hot rolling. SOLUTION: The components in a slab are composed of the ones contg., by weight, 0.01 to 0.14% C, 0.01 to 0.05% acid soluble Al, 0.003 to 0.015% N, and the balance Fe with inevitable impurities. This is heated, is subjected to hot rolling and is thereafter subjected to cold rolling for one or more times including final cold rolling at a draft of 50 to 75% to regulate its sheet thickness into final one. After decarburizing annealing, it is subjected to final annealing in the temp. range of less than the Ac1 transformation point. At the time of finish hot rolling in the stage, low friction rolling in which the friction coefficient is regulated to <=0.22 for one or more passes, and the draft in the passes in which the low friction rolling is executed is regulated to >=20%. At the time of executing the low friction rolling, roll cooling water is mixed with lubricating oil by 0.5 to 20%. volumetric fraction in an emulsion state. In this way, the grain-oriented silicon steel sheet higher in request for magnetic flux density in the high magnetic field required for a yoke material or the like can be provided. |
