简介 |
PROBLEM TO BE SOLVED : To improve the corrosion resistance of an R-Fe-B-based rare earth permanent magnet to which a protective film is applied without the deterioration in magnetic characteristics.
SOLUTION : The rare earth permanent magnet is composed of a sintered compact having a composition consisting of 27.0 to 32.0wt% R, (provided that R is one or ≥2 kinds of rare earth elements inclusive of Y), 0.5 to 2.0 wt% B, ≤2, 500 ppm O, ≤ 1, 500 ppm C, 200 to 1, 500 ppm N and the balance substantially Fe and is formed with a high-concentration layer of hydrogen of a thickness below 300 μm (not inclusive of zero) having a hydrogen concentration of ≥1, 000 ppm on its surface layer part. |