Processing technology of multi-row full complement cylindrical roller bearing rings 1. Benefits of cold treatment Precision multi-row full complement cylindrical roller bearings have high requirements for dimensional stability; More retained austenite is preserved. This retained austenite is an unstable structure. During the process of accumulating and applying the bearing, it will change continuously, thereby changing the accuracy of the bearing. To this end, a cold treatment process is used, which can reduce the retained austenite in the structure and slightly increase the hardness of the part. 2. The cold treatment process stays at room temperature after quenching: after quenching, it is necessary to make the outer and inner of the ferrule evenly cooled to room temperature before cold treatment, otherwise it is easy to crack, and immediately after cooling to room temperature (usually no more than 30min), otherwise it will be Stop the transformation of austenite to martensite. Cold treatment temperature: The temperature of cold treatment is mainly based on the martensite transformation temperature Mf of the steel, and the influence of cold treatment on machine performance and manufacturability should also be considered. For GCr15 steel, the cold processing temperature is -70°C; when the precision requirements are not very high, the ferrule or equipment is limited, the cold processing temperature can be selected from -40 to -70°C; for ultra-precision bearings, the temperature can be -70°C to -80°C Cold treatment between ℃. Supercooled temperatures affect bearing blow fatigue and contact life. Cold treatment insulation: Although the transformation of a large number of martensites is achieved when the temperature reaches a certain temperature, in order to make the surface and core of a batch of ferrules reach the cold treatment temperature evenly, a certain insulation time is required, usually 1 ~1.5h. Tempering after cold treatment: The ferrule is placed in the air after cold treatment, and its temperature is slowly raised to room temperature and then tempered in time. The temperature rise should not be too fast, otherwise it will be easy to crack; if the tempering is timely, otherwise the large residual stress in the ferrule will cause the ferrule to crack, usually not more than 2h.
The global market was valued at Hrb Bearing China in Bearing Suppliers and is expected to reach a market value of Hrb Bearing China by Bearing Suppliers, with a CAGR of Hrb Bearing China during the forecast period.
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