Abstract
It is difficult to avoid corrosion to carbon steel in acidic solutions, thus, in order to inhibit the corrosion of carbon steel during the acid pickling process, inhibitors must be added to the acid pickling solutions. In this work, the corrosion inhibition of carbon steel by three kinds of expired cephalosporins in 0.1 M H2SO4 was investigated by electrochemical, weight loss and scanning electron microscopy (SEM) methods. For the carbon steel electrode, the electrochemical results revealed that the current density was decreased, while, the charge-transfer resistance was increased in the presence of cephalosporins in 0.1 M H2SO4 corrosive solution. The weight loss results confirmed that the addition of cephalosporins decreased the corrosion rate of carbon steel. Further, the inhibition efficiency was increased with the increase in the concentration of cephalosporins. The SEM analysis of carbon steel surface was performed to confirm the effect of cephalosporins on the corrosion inhibition. The presented research demonstrated the efficient use of expired drugs for effective corrosion inhibition which could be applied to the industries at the large scale.
•Corrosion inhibition of carbon steel by three kinds of expired cephalosporins in 0.1 M H2SO4•Addition of cephalosporins could decrease the corrosion rate of carbon steel.•Inhibition efficiency increased with the increase of the concentration of cephalosporins.