Roll supporting device for a rolling mill arrangement

摘要

A roll supporting device for a rolling mill arrangement, supporting rolls rotatably to housings by double row roller bearings or multi-row roller bearings. On surfaces of bearing rings and rollers of the roller bearing are provided carbonitrided layers of 0.80% or greater in carbon content and of Rockwell hardness HRC 58 or greater. The carbonitrided layers are formed to contain residual austenite content of 25-30% by volume. By virtue of the carbonitrided layers, the strength against the surface-initiated type damage to the contact surfaces of the bearing rings and the rollers is improved, so that the enhancement of the life of the roll supporting device, especially the lives of the bearing portions thereof, can be achieved to contribute to the prolongation of inspection and maintenance periods and to the reduction of inspection and maintenance costs.