Corrosion inhibition of new thiocarbohydrazides on the carbon steel in hydrochloric acid solution

The effect of N,N′-[2,2′-thiocarbonylbis(hydrazine-2,1-diyl)bis(thioxomethylene)]dibenzamide (T1) and N,N′-[2,2′-thiocarbonylbis(hydrazine-2,1-diyl)bis(thioxomethylene)]bis(4-methoxybenzamide) (T2) on the corrosion behavior of carbon steel in 1 M HCl solution, using potentiodynamic, electrochemical impedance spectroscopy, and scanning electrochemical microscopy (SECM), is reported. The efficiency of 2.0 × 10−4 M solutions of T1 and T2 reached 96.9 and 98.2%, respectively. Adsorption of these thiocarbohydrazides on the carbon steel surface obeyed Langmuir's adsorption isotherm. The SECM results confirmed the existence of adsorption film on carbon steel.