INVESTIGATING THE EFFECT OF PH AND SALT CONCENTRATION ON CATHODIC PROTECTION OF PIPE-LINES

The corrosion rate of immersed pipelines in water with different salt concentrations was investigated. The best type of protection for these pipelines is the cathodic protection besides the various types of coatings. The cathodic protection method could give excellent protection and may reach immunity. The experiments carried out at an applied cathodic current of (0.25, 0.5,1 ICCP), various pH values (4, 7, 10), and different NaCl concentrations (tap water, 1.5%, 3%). The potential was measured with time up to 240 minutes. Full cathodic protection results in very low corrosion rate (0.3445) mm/year. However, the corrosion rate increase with decreasing pH and increasing salt concentration