The influence of the surface finishing on the electrochemical behaviour of austenitic and superaustenitic steels

The influence of surface roughness on the pitting potential and the corrosion potential of the DIN W.Nr. 1.4541 and DIN W.Nr 1.4465 stainless steels were examined using electrochemical techniques. Roughness and electrochemical tests were performed on samples with various surface finishing. Electrochemical studies were conducted in an electrochemical cell where steel electrodes were immersed in 0.1 M NaCl and 0.1 M NaCl + 0.1 M Na₂SO₄ aqueous solutions. We found for both materials when immersed in 0.1 M NaCl aqueous solution lower pitting potential than in 0.1 M NaCl + 0.1 M Na₂SO₄. The results showed that the electrochemical behaviour of the DIN W.Nr. 1.4465 is better than of DIN W.Nr. 1.4541.