Corrosion inhibition of type 430 stainless steel in an acidic solution using a synthesized tetra-pyridinium ring-containing compound

Abstract1,1′-Bis (1-methyl pyridinium-2-yl)-4,4′-dipyridinium dichloride di-iodide (TPy) and 1,1′-dimethyl-4,4′-dipyridinium di-iodide (DPy) have been synthesized and used as corrosion inhibitors for ferritic type 430 stainless steel in 0.5M H2SO4 solution. Polarization, weight loss and scanning electron microscopic measurements confirm the inhibitive action of these compounds and the increase in inhibition efficiency with an increase in concentration and temperature. The compounds enhance the passivation of the steel by increasing suppression of the critical current. The quantum chemical calculations explain the good adsorption of these compounds on the steel surface and the greater inhibition efficiency for TPy compared with that of DPy inhibitor