ANNEALED CORE AND ITS ANNEALING METHOD

• Main Authors: ABE NORITO, TAKEDA KAZUTOSHI
• Format: Patent
• Language: English
• Published: 12.02.2004
• Edition: 7
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INDUCTANCES; MAGNETS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide for a motor and a core for a transformer exhibiting superior iron-loss characteristics, especially a core for a motor and a transformer being used in an electric hybrid automobile. SOLUTION: Electromagnetic steel plates, containing 0.01 mass% or more of Al are punched into a specified shape and laminated or wound to have a core shape and then passed through welding, caulking and bolting steps, thus producing an annealed core where the oxide film on the surface layer of the annealed core has a thickness of 1.0 μm or smaller. Alternatively, electromagnetic steel plates, containing 0.01 mass% or larger of Al are punched into a specified shape and laminated or wound to have a core shape and then passed through welding, caulking and bolting steps. Subsequently, the core is annealed and de-furnacing temperature after annealing is set at 350°C or below so that the oxide film on the surface of the core is set to a thickness of 1.00 μm or smaller. The thickness of the oxide film is preferably 0.4 μm or smaller. COPYRIGHT: (C)2004,JPO