| 摘要 |
PURPOSE:To produce a grain oriented electrical steel sheet which has no glass films and has an excellent blanking property by subjecting the grain oriented electrical steel sheet worked by cold rolling to a final sheet thickness to decarburization annealing under specific temp. and atmosphere conditions, then coating an annealing and separation agent having a specific compsn. thereon and subjecting this steel sheet to finish annealing. CONSTITUTION:A silicon steel slab contg. <4.0% Si is hot rolled to a sheet material and after the sheet material is annealed, the sheet is made into the final sheet thickness of about 0.35mm by >=1 passes of the cold rolling including intermediate annealing. This thin steel sheet is subjected to the decarburization annealing in the high-temp. oxidizing atmosphere of 800-850 deg.C and 0.25-0.35 degree of oxidation PH2O/PH2 of the atmosphere. The annealing and separation agent prepd. by compounding 20-40pts. wt. one or >=two kinds of the chlorides of alkali metals such as Li, Na and K and alkaline earth metals such as Ca, Ba and Mg to 100pts.wt. MgO is applied on the steel sheet and the sheet is subjected to the finish annealing. The grain oriented electrical steel sheet having the metallic luster and the excellent blanking property is thus obtd. without forming the glass films essentially consisting of SiO2 on the surfaces thereof. |
