| abstract |
The present invention relates to a member formed from steel, in particular an outer joint member and an inner joint member of a constant velocity joint, and a method of heat treating such a member formed from steel. The heat treatment operation includes processing steps of nitriding, surface induction hardening and tempering, and these treatments are performed in succession. As a result of the nitriding operation, the joint member is provided with a surface layer 15 including a nitride and a diffusion layer 18 disposed below the nitride. Subsequently, the diffusion layer 18 is hardened by induction hardening, whereby the diffusion layer 18 has good support characteristics for supporting the surface layer 15 disposed on the upper side of the diffusion layer. [Selection] Figure 3 |