The objective of this study is to illuminate differences in metal release rates between varioussurface finishes on stainless steel. A large range of finishes exist on the market, and varies depending onarea of application and aesthetic appearance. The influence of surface finish is examined andexemplified using stainless steel grade AISI 304 in terms of individual metal release rates of the mainalloying elements: chromium, nickel and iron using inductively coupled plasma-mass spectrometry,ICP-MS, differences in the electrochemically active surface area using electrochemical impedancespectroscopy, EIS, and changes in surface composition of the outermost surface oxide using x-rayphotoelectron spectroscopy, XPS. The study includes five different cold-rolled surface finishes, threecommercial surfaces, BA, 2B and 2D (as described in the Euronorm and ASTM specifications), oneelectropolished surface, and one electropolished and passivated surface, all separately immersed in asynthetic body fluid (artificial lysosomal fluid, pH 4.5), and sampled after 8 and 168 hours at 37 ºC.The electrochemically active surface area is found to have a significant influence on the total metalrelease rate, increasing as follows: electropolished and passivated < electropolished < BA ≈ 2B < 2D.
17th International Corrosion Congress. Las Vegas, USA. October 6-10, 2008