Corrosion Of Steel In Sulfuric Acid Research Articles

Mixtures of pyrilium perchlorate derivatives with sulfur-containing compounds: inhibitors of steel corrosion in sulfuric acid

Mixtures of pyrilium perchlorate derivatives with sulfur-containing compounds: inhibitors of steel corrosion in sulfuric acid

The Efficiency of Ecballium Elaterium Extract as Green Inhibitor for Carbon Steel Corrosion in Sulfuric Acid

The Efficiency of Ecballium Elaterium Extract as Green Inhibitor for Carbon Steel Corrosion in Sulfuric Acid

Experimental and theoretical study on some azo chromotropic acid dyes compounds as inhibitor for carbon steel corrosion in sulfuric acid

Experimental and theoretical study on some azo chromotropic acid dyes compounds as inhibitor for carbon steel corrosion in sulfuric acid

Inhibitory effect of Pistacia khinjuk aerial part extract for carbon steel corrosion in sulfuric acid and hydrochloric acid solutions

The aim of this research is evaluation of the performance of Pistacia khinjuk aerial part extract (PKAPE) on the corrosion of carbon steel in 2.0 M hydrochloric acid and 1.0 M sulfuric acid solutions and comparing the differences in the behavior of the extract in these two acidic environments. For this study, the classical method of weight loss and electrochemical methods [open-circuit potential (OCP) time, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS)] were used. Based on weight loss experiments, the maximum inhibition efficiencies of 92.8% and 90.3% were obtained at 2.0 g/L of extract in 2.0 M HCl and 1.0 M H2SO4 solutions, respectively. Potentiodynamic polarization results revealed that PKAPE in both examined acidic solutions act as mixed-type inhibitor. Polarization measurements in the temperature range of 25–65 °C were carried out for different concentration to define the effect of temperature on the behavior of the extract. At all investigated temperatures, adsorption of PKAPE on the surface for both acidic media follows the Langmuir adsorption isotherm. Thermodynamic and activation parameters were calculated, and the results inferred that the adsorption of PKAPE on the surface for both acidic solutions is physisorption. Quantum chemical parameters were calculated using the density functional theory (DFT) method for main components of PKAPE to predict their adsorption on the surface.

Experimental and Theoretical Approach on the Enhanced Inhibitory Effect of Tetracyclic Triterpenes for Stainless Steel Corrosion in Sulfuric Acid

The effects of triterpene fraction (TF) on the corrosion behavior of AISI Type 321 stainless steel (SS) in sulfuric acid were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). This study shows that the inhibitor tested improve the overall corrosion resistance of stainless steel in sulfuric acid. Potentiodynamic polarization showed that TF acts as a mixed inhibitor. In addition, an adsorption model suitable for experimental data was discussed in depth. The Langmuir model gives the best fit, although all models show good agreement with the adsorption data. The effects of the inhibitor concentration and the temperature of the medium were thus evaluated. On the other hand, a hybrid method of B3LYP function and 6-31G (d, p) basis set was performed to correlate the TF molecular structure with the experimental data. In addition, a molecular electrostatic potential map was used to predict the chemical reactivity of tetracyclic triterpenes with the SS surface. The electrophilic and nucleophilic sites of adsorption were discussed, and the Fukui indices were determined. The findings obtained indicate that 8C and 9C are the most reactive sites in the tetracyclic system. Scanning electron spectroscopy confirmed the adsorption of TF on the stainless steel surface, thus supporting the experimental results.

Environmentally Safe Protection of Carbon Steel Corrosion in Sulfuric Acid by Thiouracil Compounds

Environmentally Safe Protection of Carbon Steel Corrosion in Sulfuric Acid by Thiouracil Compounds

Evaluation of 304 Stainless Steel Corrosion in Sulfuric Acid and Ethanol Media

O principal co-produto obtido na síntese do biodiesel é a glicerina. Assim investiga-se um meio para converter a glicerina em produto de utilidade, como etanol combustível. Desta forma a decomposição da glicerina ocorre pela fermentação anaeróbica realizada com a bactéria Escherichia coli. O objetivo deste trabalho foi estudar o comportamento eletroquímico do aço inoxidável 304 em H 2 SO 4 2 mol L -1 , na ausência e presença de etanol em diferentes concentrações. Foram empregadas como técnicas: medidas de potencial de circuito aberto, polarização potenciodinâmica anódica e catódica, espectroscopia de impedância eletroquímica, microscopia óptica e condutividade elétrica. A fermentação anaeróbica obteve um rendimento de 93,05 % etanol. Estudos de polarização anódica mostraram a existência de dois picos na região ativa, que de acordo com as micrografias ópticas são atribuídos a diferentes tamanhos de grãos, que ocorreram devido o tratamento térmico e associado a precipitação de caberto de cromo. Os diagramas de impedância eletroquímicos levantados mostram que o maior arco foi obtido para os sistemas contendo etanol. Nas curvas de polarização catódica averigou-se uma inibição do processo devido adsorção do etanol na superfície. A energia de adsorção foi de 2,05 104 cal k -1 mol -1 , indica ser uma adsorção química.

Experimental and theoretical studies of benzalkonium chloride as an inhibitor for carbon steel corrosion in sulfuric acid

The effect of benzalkonium chloride (BKC) on the corrosion of carbon steel in H2SO4 media has been examined by electrochemical impedance spectroscopy (EIS), polarization, weight loss, and scanning electron microscopy (SEM) methods. The results showed that the corrosion inhibition efficiency of BKC was excellent. Potentiodynamic polarization study showed that the BKC was a mixed-type inhibitor. DFT calculations were used to gain insight into the structural and electronic properties in relation to the inhibition efficiency. Molecular dynamics (MD) simulations demonstrate that chloride ion plays a significant role in the inhibition mechanism.

The Inhibition of Mild Steel Corrosion in Sulfuric Acid by New Dapsone Derivatives

Dapsone derivatives Viz., 4, 4’-sulfonylbis(N-((1H-pyrrol-2-yl)methylene)aniline) (SBPMA) and 2-dimethylamino-5-[(4-{4-[(4-dimethylamino-benzylidene)-amino]-benzenesulfonyl}-phenylimino)-methyl]-benzene (DBBPB), a new class of corrosion inhibitors have been synthesized and their corrosion inhibition efficiency on mild steel in 0.5 M H2SO4 was investigated by mass loss, Tafel polarization and AC impedance measurements. Potentiodynamic polarization studies showed that, these compounds behave as mixed type of corrosion inhibitors. The adsorption process was found to obey Langmuir isotherm model. Electrochemical impedance spectroscopy (EIS) studies revealed that polarization resistance (RP) increases and double layer capacitance (Cdl) decreases as the concentration of the inhibitors increases. Various thermodynamic parameters for the adsorption of inhibitors on mild steel were computed and discussed. FTIR, EDX and SEM analyses were performed to study the film persistency of the inhibitors.

SYNERGISTIC INHIBITION EFFECT OF CATIONIC GEMINI SURFACTANT AND CHLORIDE ION ON THE CORROSION OF STEEL IN 0.5 M H2SO4 SOLUTION

The synergistic corrosion inhibition effect between chloride ion and the cationic gemini surfactant 1,3-propane-bis(dimethyl octodecyl ammonium bromide), designated 18-3-18, on cold rolled steel immersed in 0.5 mol L−1 sulfuric acid was investigated using gravimetric, polarization, and electrochemical impedance spectroscopy (EIS) methods. The polarization curve and EIS results were in agreement with the gravimetric measurements and demonstrated that the 18-3-18/Cl− system is an excellent inhibitor of steel corrosion in sulfuric acid. Estimates of thermodynamic parameters including adsorption Gibbs free energy (), heat of adsorption (), and entropy of adsorption () were obtained. The negative value for Gibbs free energy indicates that the adsorption process is spontaneous and the adsorbed layer on the steel surface is stable. The small positive value for the heat of adsorption and the small negative Gibbs free energy indicate that both chemical and physical adsorption of inhibitor molecules occurs simultaneously. A possible mechanism for the synergistic effect is also proposed based on the experimental results.

High-temperature inhibitor of steel corrosion in sulfuric acid solutions

A new high-temperature (up to 140°C) inhibitor of steel corrosion in sulfuric acid, IFKhAN-92, that yields Z = 99% at a content of at least 1 wt % was developed. To enhance the protective effect of IFKhAN-92 at an elevated temperature, KI additions may be used. IFKhAN-92 was shown to be effective in hindering electrode reactions on steel. The high efficiency of this catalyst in H2SO4 solutions is most likely conditioned by the specific adsorption of IFKhAN-92 molecules on a metal surface.

Inhibition of mild steel corrosion in sulfuric acid by some newly synthesized organic compounds

The corrosion inhibition of mild steel in 0.5 M sulfuric acid solutions by some new synthesized organic compounds namely (E)-2-acetyl-3-(butyl amino)-N-phenyl buten-2-thioamide (compound A), (E)-3-(4-(dimethyl amino) phenyl amino)-2-acetyl-N-phenyl buten-2-thioamide (compound B) and (E)-3-(2,3-dimethyl phenyl amino)-2-acetyl-N-phenyl buten-2-thioamide (compound C) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order A > B > C. Polarization studies show that these compounds are of the mixed-type but dominantly act as an anodic inhibitors for steel in 0.5 M H 2SO 4 solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

Investigation of some oleochemicals as green inhibitors on mild steel corrosion in sulfuric acid

The inhibitive effect of four oleo chemicals (namely; 2-Pentadecyl-1,3-imidazoline (PDI), 2-Undecyl- 1,3-imidazoline (UDI), 2-Heptadecyl-1,3-imidazoline (HDI), 2-Nonyl-1,3-imidazoline (NI)), regarded as green inhibi- tors, were studied for the corrosion protection of mild steel in 0.5 M H2SO4. The methods employed were weight loss, potentiodynamic polarization and electrochemical imped- ance techniques. Scanning electron microscopy (SEM) was carried out on the inhibited and uninhibited metal samples to characterize the surface. The purity of synthesized inhibitors was checked by FT-IR and NMR studies. The inhibition efficiency increased with increase in inhibitor concentration, immersion time and decreased with increase in solution temperature. No significant change in IE values was observed with increase in acid concentration. The best performance was obtained for UDI possessing 96.2% inhibition efficiency at 500 ppm concentration. The adsorp- tion of the compounds on the mild steel surface in the presence of sulfuric acid obeyed Langmuir's adsorption isotherm. The values obtained for free energy of adsorption and heats of adsorption suggest physical adsorption. The addition of inhibitor decreased the entropy of activation suggesting that the inhibitors are more orderly arranged along the mild steel surface. The potentiodynamic polari- zation data indicate mixed control. The electrochemical impedance study further confirms the formation of a protective layer on the mild steel surface through the inhibitor adsorption.

A new inhibitor of steel corrosion in sufuric acid

A new effective inhibitor of steel corrosion in sulfuric acid, QAS-K1, from the class of quaternary ammonium salts was developed. The effects of the new inhibitor on corrosion of St3 steel in 2 M H2SO4 were studied by gravimetry at 25 and 60°C. In the individual state, QAS-K1 proved to be more effective than the industrial inhibitor catamine AB from a similar class. Anionic (5.0 mmol/l KI, 50.0 mmol/l KBr, and 5.0 mmol/l KCNS) and molecular (0.44 mmol/l diphenylthiourea (DPTU) and 0.60 mmol/l captax) additions increased the efficiency of the new inhibitor. QAS-K1 in mixtures with KI, KBr, DPTU, and captax appeared to be more effective in hindering steel corrosion in H2SO4 than similar mixtures based on catamine AB and tribenzylethanolammonium chloride. Mixtures based on QAS-K1 show a predominantly antagonistic action of the components.

Allylacetylenes and their derivatives as inhibitors of steel corrosion in sulfuric acid

New functionalized derivatives of allylacetylenes were prepared, and their ability to inhibit corrosion of St.3 low-carbon steel in 5 N sulfuric acid was studied. The effectiveness of inhibition of steel corrosion was studied in relation to the structure of acetylene derivatives, their concentration, and temperature of acidic medium.

Synergistic effect between 4-(2-pyridylazo) resorcin and chloride ion on the corrosion of cold rolled steel in 0.5 M sulfuric acid

The corrosion inhibition of 1-(2-pyridylazo)-2-naphthol (PAR) on the corrosion of cold rolled steel in 0.5 M sulfuric acid (H 2SO 4) was studied using weight loss method and potentiodynamic polarization method. Results obtained revealed that together with chloride ion, PAR is an effective corrosion inhibitor for steel corrosion in sulfuric acid. It was found that for steel corrosion inhibition in the presence of single PAR in sulfuric acid the Temkin adsorption isotherm may be used to explain the adsorption phenomenon. For the mixture of PAR and NaCl used as corrosion inhibitor, however, the Langmuir adsorption isotherm can be used to satisfactorily elucidate the adsorption of mixture of PAR and NaCl. Potentiodynamic polarization studies showed that single PAR mainly acts as a cathodic inhibitor for the corrosion of steel in 0.5 M sulfuric acid. The mixture of PAR and chloride ion, however, acts as a mixed type inhibitor that mainly inhibits cathodic reaction of the steel corrosion in sulfuric acid. By means of electrochemical polarization tests, a desorption potential at ca. −370 mV was observed for the adsorption of mixture of PAR and chloride ion, when potential reaches this value, adsorbed inhibitor molecule heavily departs from the steel surface. For the mixture of PAR and chloride ion, thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy were obtained from experimental data of the temperature studies of the inhibition process at four temperatures ranging from 30 to 45 °C, the kinetic data such as apparent activation energies and pre-exponential factors at different concentrations of the inhibitor were calculated, and the effect of the apparent activation energies and pre-exponential factors on the corrosion rates of cold rolled steel was discussed. The most suitable range of inhibitor concentration was discussed. The inhibitive action was satisfactorily explained by using both thermodynamic and kinetic models. Synergism between chloride ion and PAR was proposed. The results obtained from weight loss and potentiodynamic polarization were in good agreement.