Theoretical analysis and experiments on bearing race show that a suitable residual compressive stress on roll path of bearing race can prolong its contact fatigue life. However, residual tensile stress is often found on workpiece surface of bearing race. To actively control the residual stress state and improve fatigue life of bearing part, a new method of pre-stress hard cutting is applied. In this paper, the principle of pre-stress hard cutting for bearing race is introduced as well as the experiments on it. In the experiments, residual stress, hardness and roughness of machined surface are measured and analyzed. Moreover, micro-topography and texture characteristics of machined surface are investigated and experimental results are compared with that by grinding. It is found that we can get residual compressive stress and fine quality on machined surface of bearing race by pre-stress hard cutting and increase its productivity as well.

The analysis on load characteristics and stress state of bearing races shows that the roll path and outside layer of a bearing race are the main part to bear the load, and that residual tensile stress is often found on workpiece surface. For the purpose of improving residual stress state on machined surface of a bearing race, a method of pre-stress hard cutting is put forward. In this paper, the principle of pre-stress cutting is introduced, and method of loading stress on bearing races, together with the calculation for pre-stress, is analyzed. A set of device with expanding mandrel for realizing the process is designed too and an experiment of pre-stress cutting is carried out on a lathe with PCBN tool. The experimental results show that, by using this method, we can get residual compressive stress on machined surface layer of a bearing race and increase the quality and contact fatigue life of bearing.

Gearlike cylindrical structure can be used as outer ring of linear bearing for saving material, but the machined surface quality and roundness of this kind of bearing is beyond control in cylindrical grinding and machining efficiency is low. To solve these problems, a new method of pre-stress grinding for gearlike cylindrical surface of linear bearing is put forward based on analysis on the principle of cylindrical centerless grinding. For implementing this process, a set of device with expanding mandrel for loading tensile pre-stress on bearing ring is designed and experiment of through-feed grinding is carried out on centerless grinder. The experimental results show that this method can get fine quality of machined surface and increase the grinding efficiency greatly.

In this article, the micro-topography and texture characteristics of machined surface under the condition of high speed cutting are analyzed based on experimental observation. The forming process of machined surface and cause of the appearance are also discussed. The experimental results show that furrow and ridges, surface white layer and molten metal daub by the feed motion of cutting tool are found on machined surface due to the effect of high cutting temperature and rotating of workpiece in high speed turning process.

The forming process of serrated chip in high speed cutting for steel is analyzed based on experimental observation. The cause of serrated chip forming in high speed cutting process is the multiple effects of high cutting heat and strain rate. The shear deformation is concentrated in a narrow band and results in a shear localization. In this article, the forming mechanism of serrated chip is analyzed in accordance with the SEM photograph and metallographics got from experiment.