Electrochemical assessment of the restoration and conservation of a heavily corroded archaeological iron artifact

Abstract

This study proposes an electrochemical conservation routine applicable to iron archaeological artifacts extracted from their archaeological context and later exposed to a marine atmosphere. The case of study consisted of a Nineteenth Century anchor safeguarded in the Mexican City of Campeche. Metallurgical characterization and electrochemical studies were used to evaluate and assess the conservation process (electrochemical free chloride removal and species reduction, passivation and coating treatment evaluation) and to quantify their effectiveness. Additionally, archaeological information regarding the manufacture process was obtained. The techniques used include potential measurement, potentiodynamic polarization (polarization curves), potentiostatic measurements, electrochemical impedance spectroscopy, electrochemical noise measurements, as well as metallography studies. The method here proposed can then be used in analogous set up as a guideline example for evaluation and assessment purposes during similar procedures.