The initiation time of pitting as a function of NaCl concentration, shown in Figure , demonstrates that a decrease in NaCl concentration leads to an increase in initiation time. At 50-100 mM NaCl, the initiation time is 0.4 s, which then gradually increases to 0.5 s (average of two measurements), 0.9 s (average of two measurements), and 1.2 s at 30, 10, and 5 mM NaCl, respectively. This trend aligns well with literature and can be attributed to the more aggressive attack on the passive layer by Cl -anions at higher Cl -concentrations.