| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of producing Fe-Cr-Co permanent magnet alloy which has a high coercive force of ≥63.7 kA/m (about 800 Oe), and has excellent hot workability. <P>SOLUTION: The alloy having a composition containing, by mass, 25 to 35% Cr, 10 to 20% Co, 0.5 to 3.5% Mo, and 47 to 64.5% Fe with inevitable impurities is hot-worked at 1,250 to 850°C. The alloy after the hot working is subjected to solution treatment at 1,000 to 1,300°C for 15 min to 1 hr. The alloy after the solution treatment is subjected to heat treatment at 620 to 670°C for 30 min to 2 hr in the magnetic field. The alloy after the heat treatment in the magnetic field is subjected to first aging treatment of performing heat treatment at 600 to 650°C, also at a temperature lower than that in the heat treatment in the magnetic field for 30 min to 2 hr. The alloy after the first aging treatment is subjected to second aging treatment of performing heat treatment at 550 to 640°C, also at a temperature lower than that in the first aging treatment for 1 to 3 hr, and also for a time longer than that in the first aging treatment. Continuously to the second aging treatment, the alloy is subjected to a stage of performing cooling to 450 to 550°C at a fixed cooling rate of 2 to 10°C/hr. <P>COPYRIGHT: (C)2003,JPO |
