Corrosion response of stainless steel (SUS316) ground by ELID (Electrolytic In-Process Dressing) grinding method

To clarify the corrosion resistance of ELID ground stainless steel, electrochemical corrosion tests were carried out using a three electrode electrochemical cell connected to a computer driven potentiostat. Before the tests, morphologies of the finished surfaces were analyzed by a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive X-ray analyzer (EDX) and X-ray Photoelectron Spectroscopy (XPS). A very smooth surface was achieved by the ELID grinding process with the use of extremely fine abrasives. The value of the surface roughness (R _a) for the ELID ground sample was similar to that of the sample polished with an alumina powder. The corrosion properties of the ELID ground samples with a smooth surface were superior to those of alumina polished specimens. This was attributed to the ELID grinding, producing a very thick and stable oxide layer which showed a superior corrosion resistance compared to that of the alumina polished samples. Consequently, the ELID process seems to be a promised technology in this forthcoming future for bio-implants and other engineering components used under a corrosive environment.