軸受鋼摩耗表面の残留応力の挙動

抄録

The change of the surface residual stress of the hardened ball bearing steel which was frictionally worn out under boundary lubrication was investigated. A slider with various kinds of materials was held for two minutes against the periphery of the ball bearing steel disk which was rotating at a velocity of about 1600m/min. The materials used for the slider were classified in four groups, such as (1) steels with and without surface coating, (2) pure metals, (3) nonferrous alloys, (4) plastics.
The residual stress was measured by the X-ray method, using a Geiger counter diffractometer with CrKα radiation.
The residual stress left to the rubbed surface of the disk was various according to the kinds of the materials of the slider. In general, when the slider is of good scoring characteristics (for example, plastics and some nonferrous alloys), the residual stress was unchanged or turned to much more compressive than the original value of -25∼-30kg/mm², while, for the sliders of poor scoring characteristics, the surface residual stresses of the disks changed to nearly zero or tensile.
In addition to the residual stress change, the half height breadth of diffraction line was also observed as decreasing. Since the half-height breadth affect the fatigue strength of steel components, these values would be used as criteria for the scoring characteristics of the materials sliding on the hardened steel.