To provide a rare-earth anisotropic magnet powder having oxidation resistance and a superior magnetic property.
The rare-earth anisotropic magnet powder having the oxidation resistance and the superior magnetic property is produced by a high-temperature hydrogenation step of holding an alloy having a composition ratio of (R1-xLaX)12-14Febal.B9-10, (wherein R is a rare-earth element including yttrium except lanthanum; X=0.05-0.08; and Febal represents Fe and unavoidable impurities except a specified composition) in a treatment atmosphere which has a hydrogen partial pressure P1 of 10 to 100 kPa and is kept at a temperature T1 of 953 to 1,133 K; a structure stabilization step of holding the RLaFeB-based alloy which has passed through the high-temperature hydrogenation step, in a treatment atmosphere which has a hydrogen partial pressure P2 of 10 kPa or higher, is kept at a temperature T2 of 1,033 to 1,213 K, and satisfies a condition of T2>T1 or P2>P1; a controlled gas-removing step of holding the RLaFeB-based alloy which has passed through the structure stabilization step, in a treatment atmosphere which has a hydrogen partial pressure P3 of 0.1 to 10 kPa and is kept at a temperature T3 of 1,033 to 1,213 K; and a forced gas-removing step of removing hydrogen (H) remaining in the RLaFeB-based alloy which has passed through the controlled gas-removing step.
HAMADA NORIHIKO
MISHIMA CHISATO
