| 摘要 |
Disclosed is a process for producing an inner race for a constant velocity joint comprising the steps of: providing a steel comprising by weight carbon 0.10 to 0.25%, silicon 0.03 to 0.15%, manganese 0.20 to 0.60%, sulfur 0.003 to 0.030%, chromium 1.00 to 1.50%, titanium 0.05 to 0.20%, boron 0.0005 to 0.0050%, and nitrogen not more than 0.01% with the balance consisting of iron and impurities; hot rolling or hot forging the steel, to prepare a rolled/forged product; cold forging and machining the rolled/forged product; and carburizing, quenching, and tempering the machined rolled/forged product so that the treated steel satisfies an effective case depth of 0.4 to 0.9 mm, a thickness of abnormal-carburizing layer of not more than 15 mum, and an austenite grain size number as specified in JIS G 0551 of not less than 7.
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