Adsorption and performance assessment of 5-Mercapto-1-Methyl Tetrazole as A9M steel corrosion inhibitor in HCl medium: A detailed experimental, and computational methods.

Abstract

• MMT compound act as efficient corrosion inhibitor for A9M in 1 M HCl. • SEM and optical microscopy confirm the presence of protective layer. • The corrosion current density values decrease with the increasing concentration. • Polarization test confirmed MMT as a mixed-type inhibitor. • Results of theoretical calculations were in accordance with experimental measurements. In this work, the behavior of 5- Mercapto-1-Methyl Tetrazole “MMT” as corrosion inhibitor towards A9M steel in 0.1 N HCl acid has been examined via experimental and theoretical approaches. The experimental results confirmed MMT as a mixed-type inhibitor with a maximum inhibition efficiency of 86.87% obtained at 10 -3 M. Optic microscopy and SEM d the formation of an adsorbed-protective thin layer onto the A9M steel surface. Further interpretation of the MMT inhibiting action was carried out via DFT, MD, and MC computations.