جلوگیری از خوردگی فولاد کربنی در حین اسیدشویی

Corrosion inhibition of carbon steel during acid pickling

جلوگیری از خوردگی فولاد کربنی در حین اسیدشویی

ABSTRACT

A novel cationic surfactant, N-(2-(2-mercaptoacetoxy)ethyl)-N,N-dimethyl dodecan-1-aminium bromide), has been synthesized to study its corrosion inhibiting effect against carbon steel in 1.0 M HCl solution. The corrosion inhibition efficiency was measured by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss methods. The inhibition efficiencies obtained from these methods were in good agreement. The inhibition efficiency slightly decreased in the temperature range 30–60 °C. The synthesized inhibitor acted as a mixed inhibitor. Thermodynamic adsorption and activation parameters were discussed. Adsorption of the synthesized inhibitor was found to follow the Langmuir adsorption isotherm. A chemical adsorption mechanism is proposed.

 

ممانعت کننده های خوردگی مس Copper Corrosion Inhibitors

Copper Corrosion Inhibitors

ممانعت کننده های خوردگی مس

ABSTRACT

Copper is metal that has a wide range of applications due to its good properties. It is used in electronics, for production of wires, sheets, tubes, and also to form alloys. Copper is resistant toward the influence of atmosphere and many chemicals, however, it is known that in aggressive media it is susceptible to corrosion. The use of copper corrosion inhibitors in such conditions is necessary since no protective passive layer can be expected. The possibility of the copper corrosion prevention has attracted many researchers so until now numerous possible inhibitors have been investigated. Amongst them there are inorganic inhibitors [1], but in much greater numbers there are organic compounds and their derivatives such as azoles [2-49], amines [50-56], amino acids [57, 58] and many others.

ممانعت از خوردگی مس در محلول H2SO4 اشباع از O2

Copper corrosion inhibition in O2-saturated H2SO4 solutions

ممانعت از خوردگی مس در محلول H₂SO₄ اشباع از O₂

ABSTRACT

Corrosion inhibition of copper in O2-saturated 0.50 M H2SO4 solutions by four selected amino acids, namely glycine (Gly), alanine (Ala), valine (Val), or tyrosine (Tyr), was studied using Tafel polarization, linear polarization, impedance, and electrochemical frequency modulation (EFM) at 30 C. Protection efficiencies of almost 98% and 91% were obtained with 50 mM Tyr and Gly, respectively. On the other hand, Ala and Val reached only about 75%. Corrosion rates determined by the Tafel extrapolation method were in good agreement with those obtained by EFM and an independent chemical (i.e., non-electrochemical) method. The chemical method of confirmation of the corrosion rates involved determination of the dissolved Cu2+, using ICP-AES (inductively coupled plasma atomic emission spectrometry) method of chemical analysis. Nyquist plots exhibited a high frequency depressed semicircle followed by a straight line portion (Warburg diffusion tail) in the low-frequency region. The impedance data were interpreted according to two suitable equivalent circuits. The kinetics of dissolved O2 reduction and hydrogen evolution reactions on copper surface were also studied in O2-saturated 0.50 M H2SO4 solutions using polarization measurements combined with the rotating disc electrode (RDE). The Koutecky–Levich plot indicated that the dissolved O2 reduction at the copper electrode was an apparent 4-electron process.