The surface treatment of stainless steels often has a dramatic influence on their corrosion resistance. By processing like grinding or blasting differences may occur, which depend on the used abrasives, coolants and the energy introduced, e.g. by a higher grinding pressure. This raises the question, how dramatic is this influence on the corrosion behavior and how a manufacturer can test it. The cover picture shows results of tests on stainless steel 304, processed with normal and high grinding pressure, by using a novel and convenient testing consisting of a specific gel-pad (top figures with area ratio of pits) and electrochemical current noise measured in a specific testing electrolyte (bottom figures). A very good correlation can be seen between both methods and also between the different grinding processes, which indicate a far higher amount of pit initiations due to the comparatively higher grinding pressure.
More information can be found in: A. Burkert, H. S. Klapper, J. Lehmann; Novel strategies for assessing the pitting corrosion resistance of stainless steel surfaces; Materials and Corrosion 2013, 64, 675.