Basic Experiment of Ultrasonic Deep Rolling with Longitudinal-Torsional Vibration

Orthogonal experiments of ultrasonic deep rolling with Longitudinal-torsional vibration (UDR-LTV) and conventional deep rolling (CDR) Q235 steel were carried out to study the effects of processing parameters on surface roughness. The orthogonal experiments results show that the influence laws of processing parameters on surface roughness are the same, and the values of surface roughness obtained by UDR-LTV are smaller than that of CDR with the same processing parameters. The values of surface roughness obtained by UDR-LTV and CDR increase and then decrease with the increment of the static pressure; and increase with the increment of the feed-rate, and change a little along with the increment of the rolling speed. Meanwhile, the feed-rate has a marked effect on the surface roughness, while the rolling speed has a little effect on the surface roughness. The quadratic regression method is used to construct the mathematic model to predict surface roughness based on the experimental results. The effects of parameter interactions on surface roughness are studied. The research shows that the interaction effects of the rolling speed and the feed-rate, the static pressure and the feed-rate on surface roughness are obvious, but the interaction effect of the static pressure and the rolling speed on surface roughness is not significant. The optimal parameters for the lowest surface roughness are given by the result of orthogonal design and prediction model, which has guiding significance for the application of ultrasonic surface strengthening technology with complex vibration mode.