CORROSION INHIBITION OF PURE ZINC IN 2.5 M HF ACID SOLUTION BY USING ORGANIC AND INORGANIC SALTS.

Corrosion inhibition of pure Zinc in 2.5 M HF acid by using organic and inorganic salts such as Tri-sodium citrate, Potassium hydrogen phthalate, Sodium oxalate, Potassium dihydrogen ortho phosphate and Potassium dichromate was investigated using open circuit measurements, potentiodynamic polarization and surface examination via scanning electron microscope (SEM) techniques. The percentage of inhibition efficiency was found to increase with increasing the concentration of Tri-sodium citrate, Potassium dihydrogen ortho phosphate and Potassium dichromate but decrease with increasing the concentration of the other salts, such as Potassium hydrogen phthalate and Sodium oxalate salts. Results revealed clearly that, open circuit measurements and potentiodynamic polarization are in agreement.. Analyses of the surface by scanning electron microscope (SEM) technique confirm these results.