Increase corrosion resistance of mild steel in sulfuric acid and hydrochloric acid solutions by metoclopramide tablet

A comparative study on 1-dodecyl-2,3-dimethylimidazolium chloride ([DDMIM]Cl) and 1-benzyl-3-dodecyl-2-methylimidazol-1-ium chloride ([BDMIM]Cl) as corrosion inhibitors for N80 steel in a 15% hydrochloric acid solution was performed by surface tension tests, electrochemical measurements, weight loss, scanning electron microscopy, atomic force microscopy, and theoretical calculations. The experimental results confirm that [DDMIM]Cl and [BDMIM]Cl act as mixed-type inhibitors. The adsorption of both inhibitors on the N80 steel surface obeys the Langmuir adsorption isotherm, and [BDMIM]Cl exhibits better inhibitive performance, lower critical micelle concentration (CMC), and a lower ratio of saturation adsorption concentration on the steel surface to its own CMC than [DDMIM]Cl. The results of theoretical calculations reveal that the electron-donating/accepting capacities and hydrophobicity of the benzyl substituent in the imidazole ring are essential for preventing steel corrosion in acid media.

Section: Resultsmentioning

confidence: 99%

\frac{C}{θ} = \frac{1}{K_{ads}} + C,

∆ G_{ads}^{0} = - R T \ln (55.5 K_{ads}),

…”

Section: Resultsmentioning

confidence: 99%

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Comparative study on two imidazolium‐based ionic liquid surfactants as corrosion inhibitors for N80 steel in 15% hydrochloric acid solution

Qiao

Zeng

2020

“…[ 27 ] It is worth mentioning here that an increase in the diameter of the capacitive semicircle implies a higher charge transfer resistance and, consequently, a better corrosion protection. [ 28–31 ] As visible from the Nyquist plots (see Figure 3b), the radius of the high‐frequency capacitive semicircle gradually increases with the increase in the degree of spheroidization. The near‐complete spheroidized microstructure, namely, the WR873K‐2H specimen, exhibits the highest charge transfer resistance (see Figure 3b).…”

Section: Resultsmentioning

confidence: 99%

Effect of spheroidized microstructure on the impact toughness and electrochemical performance of a high‐carbon steel

Bairagi

Munukuti

Bhuyan

et al. 2020

The influence of cementite spheroidization on the impact toughness and electrochemical properties of a high‐carbon steel has been thoroughly investigated in this study. Heavy warm rolling, followed by 2 h of annealing, has resulted in near‐complete spheroidization, leading to a microstructure consisting of nano‐cementite globules dispersed in the ultrafine‐grained ferritic matrix. The Charpy impact test exhibited superior impact toughness with increased spheroidization. It is validated by the presence of abundant dimples in the fractographs of spheroidized specimens, in contrast to the as‐received one that experienced a brittle failure due to its lamellar pearlitic structure. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) carried out in a 3.5% NaCl solution revealed that the corrosion resistance of the alloy gets improved with the increase in the degree of spheroidization. This is attributed to the lower susceptibility of the spheroidized specimen to microgalvanic corrosion owing to the minimum area of contact between nano‐spheroidized cementite and ferrite, as elucidated with the help of EIS results aided by equivalent electrical circuit model.

“…Shifts of E corr toward cathodic and anodic potentials were observed with CPYA compared to the solution without inhibitor. Despite these shifts (−44 to +12 mV), CPYA was characterized as a mixed‐type inhibitor considering that such displacements are <±85 mV …”

Section: Resultsmentioning

confidence: 99%

Theoretical and experimental studies of a new aniline derivative corrosion inhibitor for mild steel in acid medium

Fernandes

Palmeira-Mello

Santos

et al. 2019

4‐Chloro‐N‐(pyridin‐2‐ylmethyl)aniline (CPYA) was synthesized by a simple and inexpensive method and tested as a corrosion inhibitor in acid medium for mild steel by using gravimetric studies and electrochemical measurements. An average maximum efficiency of 96.0% was achieved at 4.59 mmol/L. Corrosion kinetic and thermodynamic parameters were also analyzed. Surface analyses (atomic force microscopy and scanning electron microscopy) show that protection is enabled by adsorption on the metal, forming a film. Quantum chemical calculations were performed to access information regarding the molecular structure in the corrosive medium and to support interpretation of the results obtained by experimental methods.