from the conferences organized by TANGER Ltd.
The microstructure, hardness, and corrosion behavior of Cu-modified austenitic stainless steels (SS) were investigated in the present work. The materials were prepared by controlled melting of SS (chemical composition Cr 22 wt. %, Ni 9 %, Mo 2 %, Mn 2 %, Si 1%, P 0.045%, S 0.03%, C 0.03%, Fe bal.) with 1, 2 and 5 wt. % Cu. The ingots were thermo-mechanically processed and annealed at 1100 °C for 30 min. The materials were metallographically prepared by grounding and polishing for microscopy observation. The steels were found to consist of austenite matrix. A small amount of δ-ferrite precipitated in the matrix during solidification. The microhardness of the materials was measured by Vickers method. The hardness of Cu-modified SS was slightly reduced compared to the parent material due to Cu dissolution in austenite. The corrosion behavior of the steels was studied in physiological solution (0.9 wt. % NaCl) by electrode polarization. A three-electrode cell controlled by potentiostat was used to monitor the progress of the reaction. Corrosion potentials were shifted to more noble values with increasing Cu concentration. The corrosion rate of SS alloyed with 2 wt. % Cu was significantly reduced compared to the parent material. The results can be used as a guideline for an efficient design of Cu-modified SS for biomedical applications.
Keywords: Stainless steel, austenite, copper, corrosion, electrode potential© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.