| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for a rough shape material for a bearing ring which solves the problem of a long machining time required for a grinding process to remove the quenching strain of a ring material which is cold-rolled and ground by reducing the quenching strain during quenching operation after grinding to shorten the machining time in the grinding process, and to provide the rough shape material for the bearing ring. SOLUTION: In the manufacturing of the rough shape material for the bearing ring by cold-rolling the ring material 5 obtained by cutting a high-carbon bearing steel pipe, an inside diameter expanding rate is set 1.5 or less, an outside diameter expanding rate is set 1.4 or less. When the machining speed of the whole cold-rolling time is expressed by reduction in thickness per rotation of the ring material 1, the machining speed by rolling in a first 1/3 stage is 0.4 mm/ rotation or less, in a middle 1/3 stage, is 0.5 mm/rotation or less, and in a final 1/3 stage, is set 0.25 mm/rotation or less, and then, subjected to sizing. COPYRIGHT: (C)2003,JPO
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