To provide a method of nitriding a thin plate-shaped bearing member, by which the occurrence of defects such as warpage and stain in the thin plate-shaped bearing member can be efficiently reduced.
The nitriding treatment method comprises preparing a jig for supporting a plurality of the thin plate-shaped bearing members so that they can move within a prescribed range without contacting each other and that their plate faces become parallel to a plane other than a horizontal plane. While the plurality of the thin plate-shaped bearing members are held by the jig, they are sequentially subjected to a degreasing step, a deburring step, a cleaning step, a nitriding step at 570-650°C, a cooling step, a cleaning step and a drying step. The cooling step after the nitriding step is carried out by soaking the thin plate-shaped bearing members in an aqueous solution of a cyanide compound under an atmospheric pressure, wherein the aqueous solution has a cyanide ion concentration of ≥0.02 mol/l and is kept at 50-60°C.
Megumi Konishi
Hide Tanaka Tetsu
Ichi Hirose
Toru Miyasaka
Next Patent: METHOD OF SURFACE-HARDENING THIN PLATE-SHAPED BEARING MEMBER