Research on electrochemical machining of small-size step holes in sheet workpieces based on sacrificial active metal method

In order to machine high-quality small-size step holes in stainless steel 304 sheet workpieces, this paper proposes a new method for electrochemical machining(ECM) of small-size structures in thin plates—sacrificial active metal method, which improves the over-corrosion and stray corrosion defects of traditional ECM. Firstly, the mathematical model of potential and current density is established based on electric field theory, and the numerical simulation of traditional ECM and sacrificial active metal ECM are carried out by COMSOL, a multi-physical field simulation software. The simulation results show that the differential distribution of current density on the surface of anode workpiece with sacrificial active metal method is beneficial to forming small-size step holes. Finally, when the voltage is 10 V, the duty cycle is 50%, the rotation speed is 3 000 r/min, and the electrolyte is a mixture of 1 mol/L NaNO₃ and 0.1 mol/L C₆H₈O₇, the small-sized step hole with good machining quality is successfully obtained on the stainless steel 304 sheet, and the experimental results are consistent with the simulation results.