Improved Corrosion Resistance

Heavy oxides from welding on steel can serve as a film on the surface and indicate the Chromium / Oxide underlying metals surface has been depleted of Chromium and can be a sight of initiation for corrosion mechanisms such as crevice corrosion and pitting. 

The electropolishing process is designed to remove the discoloration and a thin film of material approximately 25-50 µm to improve the corrosion resistance of the metal achieving CCP ranges typically in the range of 450 mV when tested using cyclic polarization tests on samples of welded with 50 ppm O₂.  Tests have shown when have been welded with 20 ppm O₂ the ranges can be upward 750 mV. 

Polishing compounds, either that produced with tallow or those that leave paraffin’s on the surface used in blending welds in the manufacturing process can also mask steels from receiving proper passivation by keeping chemicals from reaching the surface of the steel. 

Electropolishing can remove residue from buffing compound improving the surface, increasing the Cr / Fe ratio’s and allow chemical passivation procedures to achieve the maximum benefit.