On the Effect of Wave Signal Input via Zero Charge Corrosion Protection in 3.5% NaCl Solution

The technique of zero charge corrosion potential (ZCCP) acts as a new alternative of cathodic protection technique. A study of wave signal input in ZCCP technique was carried out on pure Mg steel in the 3.5% NaCl solution. This experiment was conducted within 48 hours. The wave signals input that had been used in this experiment are square, triangle, and sine wave. These waveforms have an impact on the corrosion protection of the ZCCP system. The effectiveness of waveform in ZCCP technique on corrosion protection was determined by morphology observation using stereomicroscope. It is found that, the lowest consumption of current density took placed at the square wave signal which is-0.99μA/cm2. Meanwhile, for triangle and sine wave, the current density recorded were-1.694μA/cm2and-1.756μA/cm2, respectively. From the morphology observations, it is clearly seen that the square wave signal provides better corrosion protection as compared to the triangle and sine wave signal. There is no formation of localised corrosion detected on the Mg surface using square wave signal. This is because the % ‘ON’ and % ‘OFF’ in ZCCP system allows to set it to the desired value of potential.