METHOD OF IMPARTING COMPRESSIVE RESIDUAL STRESS TO BALLS

摘要

A method of imparting compressive residual stress to a first plurality of balls includes a) placing the balls between a first body having a first surface and a second body having a second surface, the first surface including a smooth contact portion, the smooth contact portion being substantially flat or convex and having a surface hardness greater than or equal to an initial surface hardness of the balls, b) imparting a compressive stress along a first diameter of the balls by pressing the first body toward the second body or the second body toward the first body or the first and second bodies toward one another with a force, and c) causing relative movement between the first surface and the second surface while maintaining the force at or above a minimum level to impart the compressive stress along other diameters of the balls different than the first diameter.

主权项

1. A method of imparting compressive residual stress to at least a surface portion of a first plurality of balls, the balls having an initial surface hardness, the method comprising:
a) placing the first plurality of balls between a first body having a first surface and a second body having a second surface, the first surface including a smooth contact portion, the smooth contact portion being substantially flat or convex and having a surface hardness greater than or equal to the initial surface hardness of the balls, b) imparting a compressive stress along a first diameter of the first plurality of balls by pressing the first body toward the second body or the second body toward the first body or the first and second bodies toward one another with a force, and c) causing relative movement between the first surface and the second surface while maintaining the force at or above a minimum level to impart the compressive stress along other diameters of the first plurality of balls different than the first diameter.