The Influence of Citric Acid on the Corrosion Process of Different Metallic Materials

Abstract The paper presents the results from a study of the corrosion behaviour of different metallic materials, such as copper, aluminium and OL 52 steel in the presences of various concentrations of citric acid added in neutral solution (Na2SO4 0.25 M). Citric acid (2-hydroxy-1, 2, 3-propanetricarboxylic acid) is among the most commonly utilized compounds in the food and beverage sectors. This non-toxic chemical can be derived from natural, renewable sources such as citrus fruits, pineapples, kiwis, raspberries, strawberries, and both black and red currants. Corrosion studies carried out previously demonstrated a mixed effect of citric acid, it can be a good inhibitor for aluminum alloys in a strongly acidic or strongly basic media as well as in neutral NaCl media, for low carbon-steel and copper in an acidic environment, but also, a good, accelerated corrosion agent in an alkaline solution for metals such as iron, copper, zinc and tin. Potentiodynamic polarization and chronoamperometry techniques were used in the experimental part of this paper to evaluate the inhibition efficiency of the citric acid in test solutions. Also, Tafel method for the kinetic parameters determination for studied corrosion process.