This invention relates to a method and an apparatus for performing the
method of inducing compressive residual stress along the surface of a
part. In the preferred embodiment of the invention, the method includes
burnishing or deep rolling a surface using a first and a second roller or
ball burnishing members, whereby the first and second burnishing members
may have a different diameter and/or modulus of elasticity. In another
preferred embodiment of the invention, the burnishing operations may be
performed while the surface of the part is at different temperatures.