Method of inducing compressive stresses near surface areas of metal structures such as balls, involves arranging the ball between grooves, and rotating a disc at predetermined ratio, such that very uniform hardening of ball is achieved

摘要

The method involves defining two discs (2.1,2.2) having respective peripheral and circular-segment-shaped grooves (5.1,5.2) at their outer peripheral edges (4.1,4.2). The rotation axes (3.1,3.2) of the two discs are arranged parallel to each other such that a mutual distance (AD) which is larger than the sum of the two radii (R-S1,R-S2) of the discs, is maintained. The radius of the ball (1) is smaller than that of the grooves. The ball is arranged between the grooves, and one of the discs is rotated at predetermined ratio, such that very uniform hardening of the ball is achieved. Independent claims are included for the following: (1) an apparatus for inducing compressive stresses near surface areas of balls; and (2) a ball.