Effect of Ultrasonic Waves on the Pitting Potentials of 18-8 Stainless Steel in Sodium Chloride Solution

Critical pitting potential and protection potentials were measured potentiodynamically in 0.1N NaCl solution vibrated by a 200 kHz ultrasonic wave. The critical pitting potential was more noble in this environment than in a hydrostatic solution. This fact was confirmed potentiostatically. In hydrostatic solution, the protection potential seems to decrease with the increase of the level of pit propagation. When the electrodes are radiated by ultrasonic wave, the protection potential can be defined as 120 mV (SCE) and is independent of the degree of pit propagation.