A kind of method after salt bath quenching of extra-large self-aligning bearing ring

Abstract

The invention discloses a method for an ultralarge aligning bearing ring after salt bath quenching. The method comprises the following process steps: firstly, an outer diameter groove of a large aligning bearing ring and hole asbestos rope water staining glass are blocked; the ultralarge aligning bearing ring moves to a loading table for cleaning; the cleaned bearing ring is insulated in a heatingfurnace by austenite heating; the heated and insulated bearing ring is quickly transferred to a salt bath groove for salt batch quenching; when the internal temperature of the bearing ring reaches 170 DEG C, the bearing ring is transferred to an air cooling table for air cooling until the temperature of the ring is 100-110 DEG C; after air cooling, the after-cleaning is performed on the bearing ring; the temperature of cleaning liquid is controlled within 70-80 DEG C; a tempering furnace performs tempering; and the tempering temperature is controlled within 170+-5 DEG C. The method saves thesecondary cooling flow, can effectively prevent the quality problem of easy generation of quenching cracks at stress concentrated parts, reduces a lot of wastes, reduces the production cost, and greatly improves the product quality.

Description

technical field [0001] The invention relates to the technical field of bearing heat treatment, and mainly relates to a method for an extra-large self-aligning bearing ring after salt bath quenching. Background technique [0002] Salt bath quenching of bearing rings refers to the method of immersing the processed bearing parts in a molten salt bath for rapid cooling in order to increase their hardness. At present, the extra-large self-aligning bearing ring is quenched and tempered in salt bath martensite in the "AICHELIN" roller hearth furnace salt bath quenching production line, such as figure 1 As shown, the common process flow is: move the extra-large self-aligning bearing ring to the roller bottom feeding table, drive it through the roller rod, and enter the pre-cleaning tank 1 for pre-cleaning (cleaning temperature 80-90°C), After the pre-cleaning is completed, the workpiece is driven by the roller rod, and the workpiece enters the protective atmosphere roller hearth qu...

AI Technical Summary

Problems solved by technology

[0003] Since the outer diameter of the extra-large self-aligning bearing is generally provided with grooves and holes, and the ribs of the inner ring are generally provided with oil grooves, the positions of the grooves, holes, and oil grooves are just the most suitable for the ring wall of this type of bearing. Thin places and large wall thickness differences are all stress concentration places. Due to the large size and heavy weight of this type of ferrule, the heat dissipation is slow during the cooling process, and there is a large stress difference in the quenching and cooling process. If the conventional process is used The temperature of the ferrule after air cooling reaches 100-110°C. In order to clean the salt solution on the surface of the ferrule, the temperature of the cleaning liquid after cleaning needs to be 70-80°C. The temperature of the ferrule after cleaning is nearly 100°C , the temperature of the secondary cooling tank is not higher than 10 ℃, so cracks appear in the bearing after quenching. In the actual production and processing process, although the outer diameter groove and hole are filled with asbestos rope dipped in water glass before processing , but still cannot avoid the occurrence of this phenomenon, especially in the stress concentration parts such as the sudden change of the cross section, the bottom of the oil groove, and the circumference of the hole, the quenching cracks are more obvious, which seriously affects the production cost and product quality, and the product eventually becomes a waste product

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