Spherical roller bearings caused by fracture of the reasons for what?
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| Time：2016.11.04 News Sources：Shandong Xinkaite bearing Co.,Ltd. Views：
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Bearing the technical staff found that the fracture is a troubled self-aligning roller bearing quality problems, and defect fracture is the main form of ring fracture, which is mainly due to their own raw material problems or production operations properly, equipment can not run properly .
First, raw materials
Incompletion of raw materials, loose, brittle element segregation or carbide solution, mesh, ribbon, unfortunate homogeneous and other defects in the processing is not eliminated or improved, will cause stress concentration, weakening the basic strength of the ring, a crack source. Preventive measures is to adhere to the main channel supply, try to purchase stable and reliable quality of steel, strengthen the purchase of steel warehousing inspection, from the source to good relations.
Second, production and equipment
1. Forging: Forging process if the over-burning, overheating, cracking into a network of carbide and so will reduce the toughness and strength of rings. So must always strictly control the processing temperature, circulation heating and calcination cooling conditions (such as spray cooling), etc., especially the larger varieties of rings after the final forging, the temperature above 700 ℃, shall not be stacked.
2. Heat treatment: Close monitoring of heat treatment equipment is an important work in the workshop.
Monitor the reliability of the equipment. On the instrument, thermocouple and other important temperature control devices to be closely monitored to ensure accurate and reliable measurement data; the error should be replaced in time, is strictly prohibited disease operation.
Quenching and cooling conditions. To address the large varieties of FAG spherical roller bearing ring soft spots and other defects should be measured quenching oil composition and performance of substandard requirements to be replaced in advance to rapid quenching oil replacement in order to enhance quenching for the medium quenching capacity, Improve quenching cooling conditions.
Strict tempering process. For the occurrence of more varieties of fracture phenomenon, the coarse grinding in the ring after the second tempering, which can further stabilize the organization and size of rings, but also reduce the grinding stress, improve the performance of grinding metamorphic layer.
3. Grinding process monitoring. Finished spherical roller bearing rings are not allowed to have grinding burns and grinding cracks exist, especially with the inner surface of the cone should not have burns. Ferrule should be checked after pickling, remove the burn products, severe burns can not be rework or rework failed should be scrapped, does not allow grinding burns into the assembly process ring.
Third, the ring overload fracture and the possibility of fatigue fracture at the same time, especially in poor service conditions of the spherical roller bearings. Fracture of the ring on the study, not only from the material and the production process defects arising from these angles to consider, but also FAG spherical roller bearing parts of the structural size, processing measurement tools, processing technology, spherical roller bearings Service conditions and other factors to carry out research and analysis.
1. Spherical roller bearing structure and service conditions. Different structure suitable for different service conditions; Spherical roller bearing parts of different processing technology is not the same, it will affect its quality. Therefore, we should develop new structure products to adapt to different service conditions, and in the self-aligning roller bearing instructions on the use of their conditions of service or performance to facilitate the choice of customers.
2. Strengthen the process research, improve the processing technology, improve processing quality, reduce the possibility of defects in processing. As in the heat treatment, the larger varieties of inner and outer ring, as far as possible with the lower quenching temperature, to extend the holding time to improve the alloying concentration, increasing the martensite fracture strength, and to ensure quality under the premise of selection of higher Tempering temperature to enhance the impact toughness of the workpiece.
3. Improve the processing monitoring means to promote the improvement of processing quality. Such as improving the curvature of the flow channel position monitoring to improve the spherical roller bearing assembly after the overall performance and improve the self-aligning roller bearing working conditions.
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