CPC C21D 9/40 (2013.01) [C21D 1/18 (2013.01); F16C 33/44 (2013.01)] | 5 Claims |
1. A method of manufacturing a cage for a constant velocity joint, the method comprising:
a cutting operation of forming a structure having an outer shape by cutting a cylindrical pipe;
forming an outer circumference of the cut structure to have a curved surface thereon;
performing a turning operation on a surface of the formed structure;
a punching operation of forming a window in the surface of the structure on which the turning operation is performed;
a broaching operation of processing an edge of the window formed via punching; and
a heat treatment operation of performing a heat treatment to the broached cage,
wherein the heat treatment operation includes:
increasing a temperature of the cage to 880° C. for 100 to 140 minutes;
maintaining the temperature of the cage at 880° C. for 80 to 150 minutes;
cooling the cage to 200 to 270° C.; and
when the slow cooling is completed, performing austempering in a salt bath treatment tank in a range of 200 to 270° C. for 130 to 170 minutes.
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