METHOD FOR PRODUCING POWDER FOR MAGNET, AND METHOD FOR PRODUCING RARE EARTH MAGNET

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PROBLEM TO BE SOLVED : To provide a method for producing powder for a magnet capable of producing powder for a magnet excellent in magnetic properties at high productivity, and a method for producing a rare earth magnet. SOLUTION : Provided is a method for producing powder 1 for a magnet comprising : a preparation step where rare earth-iron based alloy powder 10 composed of a plurality of rare earth-iron based alloy particles 11 is prepared; a surface nitriding step where the rare earth-iron based alloy powder is heat-treated in a nitrogen element-containing atmosphere to form nitrided powder 20 having a nitrogen holding region 21 where the respective rare earth-iron based alloy particles are intruded into the vicinity of the surface thereof; and a magnetic field treatment step where the nitrided powder is applied with a fixed magnetic field in a nitrogen element-free atmosphere and is heat-treated to diffuse the nitrogen in the nitrogen holding region into the rare earth-iron based alloy particles, thus powder 1 for a magnet composed of rare earth-iron-nitrogen based alloy particles substantially uniformly nitrided over the whole of the rare earth-iron based alloy particles is formed. In the magnetic field treatment step, heat treatment temperature is 280 to 430°C and magnetic field strength is 2 to 12T. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2016, JPO&INPIT