Electrochemical polishing can improve the reflective performance of parts; improve corrosion resistance; reduce the surface hardness of machined parts; and reduce the friction coefficient due to the reduction of surface roughness. Electrochemical polishing can also be used to remove burrs and so on. Compared with mechanical polishing, electrochemical polishing has the following characteristics.
(1) Mechanical polishing will produce surface hardened layer and abrasive inclusions, which will reduce the corrosion resistance of stainless steel, while electrochemical polishing will produce a passivated surface and increase the corrosion resistance of stainless steel.
(2) Electrochemical polishing has certain requirements for the substrate. For example, when the metallographic structure is not uniform, it will produce an uneven polished surface, and deep scratches cannot be polished. The mechanical polishing has much lower requirements on the substrate.
(3) For parts with complex shapes, wires, thin plates and small parts, electrochemical polishing is much easier than mechanical polishing.
(4) The production efficiency of electrochemical polishing is higher than that of mechanical polishing, but large workpieces cannot be put in the polishing tank and require a particularly large current, which makes it difficult to perform electrochemical polishing.
(5) The surface current density of the electrochemically polished workpiece must be uniform, and if necessary, a pictograph cathode is needed, otherwise the surface brightness will be uneven.
(6) The current is relatively large during electrochemical polishing, and the fixture and the workpiece must have a large enough contact area and good contact, otherwise local overheating will burn the workpiece.
(7) Some polishing processes used for austenitic stainless steel cannot be used to polish martensitic stainless steel, which are prone to corrosion