Inhibition of 2-pyridinecarboxaldehyde Thiosemicarbazone in HCl Solution for Q235 Steel

A new corrosion inhibitor named 2-pyridinecarboxaldehyde thiosemicarbazone (2-PCT) was synthesized and the inhibition effect on Q235 steel in 1 mol·L-1 HCl solution was investigated by weight loss method, potentiodynamic polarization curves and electrochemical impedance spectroscopy. The surface morphology was observed by scanning electron microscopy. The results show that 2-PCT has excellent inhibition effect on Q235 steel in HCl solution and its inhibition efficiency reached up to 95.38% when the inhibitor concentration was 1 mmol·L-1, suppressing both cathodic and anodic corrosion processes. The adsorption of 2-PCT on Q235 steel surface obeys Langmuir adsorption isotherm equation.