Influence of surface microstructure parameters on wear of steel ball unfolding wheel

The unfolding wheel is an important part of the steel ball tester in rolling bearing industry, and it is easy to be worn out. In this study, the pit microstructure is applied to the working surface of the unfolding wheel to reduce wear, improve its service life and reduce the testing cost of the steel ball. To analyze the influence of surface microstructure geometrical parameters on the abrasion of unfolding wheel under dry friction condition, the following research was conducted. First of all, the influence of shape, area, depth, and spacing of the microstructure pits on the abrasion of the specimen surface is studied by the orthogonal test method. Then, the subsurface stress of microstructure in contact with the steel ball is analyzed by ANSYS software. Comparing the simulated stress distribution with experimental wear mass, it is found that the more concentrated the high-stress area, the less wear. The diamond microstructure with a single pit area of 3.14×10-2 mm2 and a depth of 100 μm has the best abrasion reduction effect. Finally, the mathematical models including microstructure geometrical parameters for calculating the wear mass of microstructure surface are established. The mathematical models can be used to predict the life of steel ball unfolding wheel and assist the design.