Alleviation of Iron Corrosion in Chloride Solution by N,N′-bis[2-Methoxynaphthylidene]amino]oxamide as a Corrosion Inhibitor

The alleviation of iron corrosion in 3.5% NaCl sodium chloride solution using N,N′-bis[2-methoxynaphthylidene]amino]oxamide (MAO) as a corrosion inhibitor has been reported. The work was achieved using various investigation techniques. Potentiodynamic cyclic polarization (PCP) displayed a powerful inhibition for the corrosion via reducing the iron’s cathodic and anodic reactions. This was reflected in reduced corrosion currents and increased polarization resistances in the presence and upon the increase of MAO concentration. The electrochemical impedance spectroscopy results indicated that MAO molecules provoke the corrosion resistance via increasing polarization resistance. The power of MAO on decreasing pitting attack was also investigated through measuring the change of current with time at −0.475 V(Ag/AgCl). Scanning electron microscopy images were taken of the surface after the current–time measurements were performed in the absence and presence of MAO. The current-time experiments indicated that MAO highly mitigates the corrosion of iron. The energy dispersive X-ray analyzer reported the products found on the tested surfaces. The effect of extending the exposure time from 1 h to 48 h was also tested and was found to alleviate the corrosion of iron, whether MAO molecules are absent or present.

Microbiologically Influenced Corrosion of Iron by Nitrate Reducing Bacillus Sp

Iron has played a crucial role in the human ecosystem currently in transportation, manufacturing, and infrastructure. Iron oxide is known as rust, usually the reddish-brown oxide formed by iron and oxygen reactions in moisture from water or air. Microbiologically influenced corrosion (MIC) is a significant problem to the economic damage, especially in industrial sectors and its direct presence with nitrate/iron-reducing bacteria. This paper aims to explore the MIC of iron by nitrate-reducing Bacillus sp. including the redox reaction occurs, microbiologically influenced corrosion, iron/nitrate-reducing and mechanisms of microbial iron/nitrate reduction.

Impediment of Iron Corrosion by N,N′-bis[2-hydroxynaphthylidene]amino]oxamide in 3.5% NaCl Solution

Hydrazone [N,N′-bis[2-hydroxynaphthylidene]amino]oxamide] derived from the condensation of ethanedihydrazide with 2-hydroxynaphthalene-1-carbaldehyde was synthesized and assessed on the basis of elemental analysis (CHN) and spectral (IR, mass, 13C/1H NMR and UV-Vis) measurements. The influence of N,N-bis([2-hydroxynaphthylidene]amino)oxamide (HAO) in terms of the inhibition of iron corrosion in concentrated sodium chloride solution (3.5 wt.% NaCl) after various exposure periods was assessed. Numerous electrochemical and spectroscopic assessment techniques were performed. Cyclic potentiodynamic polarization experiments indicated that the presence of HAO and its increased concentration decreased the corrosion of iron in NaCl solution by decreasing the corrosion values, anodic and cathodic currents, and corrosion rate. The electrochemical impedance spectroscopy results showed that HAO molecules greatly increased the corrosion resistance. The chronoamperometric experiments performed at −475 mV (Ag/AgCl) revealed that the HAO molecules decreased the absolute currents and reduced the probability of the occurrence of pitting corrosion. The effect of HAO on the inhibition of iron corrosion was also confirmed through scanning electron microscopy micrographs and energy-dispersive X-ray profile analyses, which proved that the surface of the iron sample exposed to chloride solution alone was pitted, while the presence of HAO molecules reduced the severity of the pitting corrosion. The results confirmed that the presence of HAO molecules inhibits the corrosion of iron and this impact increased when the exposure time was increased to 48 h.