CONSTITUENT MEMBER OF BEARING, PROCESS FOR PRODUCTION OF SAME, AND BALL-AND-ROLLER BEARING PROVIDED WITH THE CONSTITUENT MEMBER

摘要

A constituent member of a bearing, which can prolong the life of a ball-and-roller bearing and can ensure sufficient static load carrying capacity and dimensional stability; a process for production of the constituent member; and a ball-and-roller bearing which has a long life and exhibits sufficient static load carrying capacity and dimensional stability. A workpiece obtained by shaping a steel containing 3.2 to 5.0mass% of Cr and 0.05 to less than 0.5mass% of V is subjected to heat treatment such as carbonitriding, whereby a constituent member of a ball-and-roller bearing is produced.  In the constituent member thus produced, the contents of C and N in the surface layer extending from the surface of the member to a depth of 10µm fall within the ranges of 1.1-1.6mass% and 0.1-1.0mass% respectively; the Vickers hardness at a depth of 50µm from the surface falls within the range of 740 to 900 (62-67 in terms of Rockwell C hardness); the content of ?-iron at a depth of 10µm from the surface falls with the range of 20-55vol%; vanadium nitride particles having particle diameters of 0.2-2µm and/or vanadium carbonitride particles having particle diameters of 0.2-2µm are made present in the surface layer extending from the surface to a depth of 10µm; and the area fraction of the particles in the surface layer extending from the surface to a depth of 10µm falls within the range of 1-10%.