Potentiodynamic tests and electrochemical impedance spectroscopy of injection molded 316L steel in NaCl solution

Cyclic polarization tests of injection molded 316L steel were carried out i n 3%, NaCl solution. The microstructure of the as-tested samples was studie d by optical and scanning electron microscopy, The corrosion resistance of injection molded 316L steel was also evaluated studying the evolution of el ectrochemical impedance spectroscopy at the open-circuit potential for imme rsion periods varying from 1 to 78 days in aerated salt solution, The penet ration of the electrolyte solution through surface open pores as a function of the immersion time has also been addressed so the effect of porosity on the corrosion behavior was investigated, The results demonstrated that the corrosion resistance of the injected steel is affected by the presence of open pores, as they act towards increasing the effective surface area of th e material. This fact was confirmed by an increase in the corresponding val ue of the double layer capacitance, Cdc and a decrease in the value of the charge transfer resistance, R,. (C) 2001 Elsevier Science Ltd. All rights r eserved.