Microelectrode Monitoring the Crevice Corrosion of Titanium

Abstract

Crevice corrosion of titanium metal in hot NaCl solution was investigated with the aid of microelectrodes. Potential, pH, and Cl− ion activity inside and outside the crevice were measured with a 0.1 M KCI Ag/AgCl reference microelectrode, tungsten microelectrode, and Ag/AgCI chloride ion-selective microelectrode, respectively. The pH and Cl− activities were calculated from standard potential–pH and potential–log [Cl−] calibration curves. The crevice corrosion rate was found to increase with an increase in temperature, [Cl−], and [H+]. The rate also increased with a decrease in the crevice gap, while incubation time for crevice corrosion was prolonged with increased oxygen concentration in the solution.