Effect of Wheel Truing on Wheel Rim Axial Residual Stress

Recent x-ray diffraction testing of wheels with machined treads showed that axial residual stresses in the wheel rim were different than the axial residual stresses in Vertical Split Rim (VSR) wheels, and service worn wheels with no machining. As a result, a larger study was conducted at the wheel shops of major North American railroads. Tread damaged wheelsets were machined to remove tread damage and restore the flange/tread profile. The amount of metal removed from the treads was recorded, wheels were demounted, and slices were removed from the machined wheel rims at pre-marked areas for x-ray diffraction testing. The wheel rim axial residual stress patterns for the machined wheels are presented and are compared to the axial residual stress patterns for VSR wheels and used wheels with no machining. Data are presented for both forged and cast wheels. Implications for improved service performance from reduced tread damage are also discussed.