Experimental study on ultrasonic-assisted electrolyte plasma polishing of SUS304 stainless steel

A new method of ultrasonic-assisted electrolyte plasma polishing (UEPP) is proposed to solve the problem that the oxidation layer generated on the anode workpiece surface in the process of electrolytic plasma and polishing (EPP) cannot be removed completely, which affects the polishing efficiency and surface quality of the workpiece. Firstly, the polishing mechanism of UEPP is described and set up an experimental platform. Taking SUS304 stainless steel as the experimental object, comparative experiments of UEPP and EPP polishing are carried out to verify the beneficial effect of ultrasonic vibration on improving polishing efficiency and polishing quality. The results show that under the same polishing parameters, the introduction of ultrasonic vibration can improve the polishing efficiency by nearly 30%. After UEPP process, the workpiece has better surface texture, the number of surface scratches is greatly reduced, and lower surface roughness can be obtained. In addition, 40 kHz is the best ultrasonic vibration parameter. The optimization experiments of UEPP polishing process parameters are further carried out. For SUS304 stainless steel, the optimal polishing process parameters are power supply voltage of 250 V, polishing solution concentration of 4%wt, polishing solution temperature of 80 ℃ under 40 kHz ultrasonic-assisted conditions. The surface roughness of the experimental workpiece can be reduced from the initial Sa0.5 μm to Sa0.02 μm after 40 min of polishing under the optimized process parameters.