scholarly journals Effect of Cr on Aqueous and Atmospheric Corrosion of Automotive Carbon Steel

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2444
Author(s):  
Sang-won Cho ◽  
Sang-Jin Ko ◽  
Jin-Seok Yoo ◽  
Yun-Ha Yoo ◽  
Yon-Kyun Song ◽  
...  

This study investigated the effect of Cr alloying element on the corrosion properties of automotive carbon steel (0.1C, 0.5Si, 2.5Mn, Fe Bal., composition given in wt.%) in aqueous and atmospheric conditions using electrochemical measurement and cyclic corrosion tests. Three steels with 0, 0.3, and 0.5 wt.% Cr were studied by electrochemical impedance spectroscopy. Polarization resistance (Rp) of 0.3 Cr and 0.5 Cr steels was higher than that of 0 Cr steel, and the Rp also increased as the Cr content increased. Therefore, Cr increases the corrosion resistance of automotive carbon steel immersed in a chloride ion (Cl−)-containing aqueous solution. In the cyclic corrosion test results, Cl− was concentrated at the metal/rust interface in all of the steels regardless of Cr content. The Cl− was uniformly concentrated and distributed on the 0 Cr steel, but locally and non-uniformly concentrated on the Cr-added steels. The inner rust layer consisted of β-FeOOH containing Cl− and Cr-goethite, while the outer rust layer was composed of amorphous iron oxyhydroxide mixed with various types of rust. FeCl2 and CrCl3 are formed from the Cl− nest developed in the early stage, and the pitting at CrCl3-formed regions are locally accelerated because Cr is strongly hydrolyzed to a very low pH.

2021 ◽  
Vol 12 (5) ◽  
pp. 7075-7091

The extract of Fucus spiralis (FS) was tested as a corrosion inhibitor of carbon steel in a 1M HCl medium. The anti-corrosion properties were analyzed by gravimetric and electrochemical techniques such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The surface characterization of carbon steel submerged in the optimal solution was carried out using UV-Visible, UV-Vis-NIR, and Optical microscopy analyses. Electrochemical and gravimetric results demonstrated that inhibitory efficiencies increase with increasing inhibitor concentration and the efficiency reaches 87% at a concentration of 0.5 g/L. According to Tafel extrapolated polarisation measurements, the FS also worked as a mixed-type corrosion inhibitor and changed the mechanism of anodic reactions. EIS analysis showed that a depressed capacitive loop dominates the Nyquist plot of impedance and enhances the polarization resistance (Rp) to 161.9 Ω cm2 with a reduction of the double layer capacity (Cdl) of carbon steel to 61.8 μF/cm2. This protection is assured by an adsorption mechanism based on the isothermal Langmuir adsorption model, which positively affects the thermodynamic parameters. UV-Visible, UV-Vis-NIR analyses exhibited that inhibitor decreases the iron oxides like hematite, Magnetite, and Goethite, Maghemite, Lepidocrocite, δ-FeOOH of the metal surface and delays the dissolution of the bare metal of iron to the ferrous ions, notably that optical morphology showed that FS extract decreases the aggressivity of HCl.


2009 ◽  
Vol 79-82 ◽  
pp. 1017-1020 ◽  
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Song Lian Bai ◽  
Zhou Hua Jiang

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.


2020 ◽  
Vol 61 (3) ◽  
pp. 506-514
Author(s):  
Kyung-Tae Kim ◽  
Hiroaki Tsuchiya ◽  
Koushu Hanaki ◽  
Masato Yamashita ◽  
Shinji Fujimoto

2019 ◽  
Vol 272 ◽  
pp. 01001
Author(s):  
Nadia HAMMOUDA ◽  
Kamel BELMOKRE

The purpose of the different operations under the term surface preparation is to get a clean surface able to be coated. It is essential to adapt this preparation in terms of the metallurgical nature of the substrate, cleanliness, its shape and roughness. Surface preparations especially the operations of sandblasting, polishing, or grinding prove of capital importance. It allows to modify the superficial properties of these materials, after these treatments the surface becomes very active. This paper evaluates the mechanical surface treatments effect by sandblasting (Sa 1.5 and Sa 2.5) on the electrochemical corrosion characteristics of C-1020 carbon steel in 3% NaCl solution electrolyte simulating aggressive sea atmosphere. Investigations are conducted using stationary (free potential "E-t, polarization curves "E-i", the Tafel rights and the Rp) and nonstationary electrochemical tools such as electrochemical impedance. The results obtained allowed us to highlight that sandblasted carbon steel degrades with immersion time because of the roughness of the surface. These results were confirmed by the plot of the electrochemical impedance diagrams, confirming that the process governing kinetics is under charge transfer control. Good protection against corrosion cannot be obtained only with a good surface preparation of the adapted steel.


2017 ◽  
Vol 64 (6) ◽  
pp. 644-653 ◽  
Author(s):  
A.U. Chaudhry ◽  
Vikas Mittal ◽  
M.I. Hashmi ◽  
Brajendra Mishra

Purpose Inorganic oxide addition can be synergistically beneficial in organic coatings if it can impart anti-corrosion properties and also act as an additive to enhance physical and/or chemical properties. The aim of this study was to evaluate the anti-corrosion benefits of nano nickel zinc ferrite (NZF) in the polymer film. Design/methodology/approach The time-dependent anti-corrosion ability of NZF (0.12-1.0 per cent w/w NZF/binder), applied on API 5L X-80 carbon steel, was characterized by electrochemical techniques such as open circuit potential, electrochemical impedance spectroscopy, linear polarization resistance and potentiodynamic. Characterization of corrosion layer was done by removing coatings after 216 h of immersion in 3.5 per cent w/v NaCl. Optical microscopy, field emission scanning electron microscopy and X-ray diffraction techniques were used to characterize the corroded surface. Findings Corrosion measurements confirm the electrochemical activity by metallic cations on the steel surface during corrosion process which results in improvement of anti-corrosion properties of steel. Moreover, surface techniques show compact corrosion layer coatings and presence of different metallic oxide phases for nanocomposite coatings. Originality/value The suggested protection mechanism was explained by the leaching and precipitation of metallic ion on the corroded surface which in turn slowed down the corrosion activity. Furthermore, improvement in barrier properties of rubber-based coatings was confirmed by the enhanced pore resistance. This work indicates that along with a wide range of applications of NZF, anti-corrosion properties can be taken as an addition.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guiyang Wu ◽  
Xikui Gu ◽  
Wanwei Zhao ◽  
Rui Fan ◽  
Ting Mao

Purpose This paper aims to study the effect of chloride ions concentration on the corrosion behavior of carbon steel in methyldiethanolamine (MDEA) aqueous solution in the sight of different process parameters of purification plant. Design/methodology/approach Due to the decrease of filtration efficiency and separation efficiency, the chloride ion in the desulfurization solution is enriched. The corrosion behavior of carbon steel under chloride ion enrichment environment was studied by weight-loss method, electrochemical impedance spectroscopy, cyclic polarization curve, X-ray photoelectron spectroscopy and scanning electron microscopy. Findings The results show that temperature and hydrogen sulfide loads are the main factors of corrosion in CO2-MDEA-H2O-H2S environment. The enrichment of chloride ions reduces the corrosion rate at low temperature but promotes the corrosion rate at high temperature. The chloride concentration should be controlled below 3000 mg/L, and no pitting corrosion was found under the experimental conditions. Originality/value The effect of chloride ion enrichment on MDEA solution corrosion shows that at low temperature, the increase of chloride ion will reduce the acid gas load and increase the density of corrosion products, so as to reduce the corrosion; on the contrary, at high temperature, the density of corrosion products will decrease and the corrosion will be intensified as well. It is believed that the chloride ion should be controlled below 3000 mg/L according to the results of the tests.


CORROSION ◽  
10.5006/3408 ◽  
2020 ◽  
Vol 76 (4) ◽  
pp. 335-343
Author(s):  
Kyung-Tae Kim ◽  
Hiroaki Tsuchiya ◽  
Koushu Hanaki ◽  
Masato Yamashita ◽  
Shinji Fujimoto

In the present work, the modification of a rust layer on a carbon steel surface was examined during a cyclic corrosion test. The rust layer grown in a coastal region of Japan was used as a model rust layer. The x-ray diffraction analysis of the model rust layer revealed that the layer consisted of α-FeOOH, β-FeOOH, γ-FeOOH, and Fe3O4. During the cyclic corrosion test, an additional immersion of the surface in solutions containing metal cations such as Mg2+, Al3+, Cu2+, or Ni2+ was performed. The additional immersion in the cation-containing solutions modified the model rust layer, that is, the fraction of stable α-FeOOH increased in the rust layer. Furthermore, the modification of the model rust layer could suppress the corrosion of steel. The decreased corrosion rate was attributed to the suppressed cathodic reduction of the rust layers due to the presence of the stable α-FeOOH in the rust layers.


2013 ◽  
Vol 58 (2) ◽  
pp. 505-508 ◽  
Author(s):  
S. Sunada ◽  
N. Nunomura

Powder metallurgy (P/M) process has the advantage of better formability to fabricate complex shape products without machining and welding. And recently this P/M process has been applied to the production of aluminum alloys. The P/M aluminum alloys thus produced also have received considerable interest because of their fine and homogeneous structure. Many papers have been published on the mechanical properties of the aluminum alloys produced by P/M process while there have been few on their corrosion properties from the view point of electrochemistry. In this experiment, therefore, two kinds of 7075 aluminum alloys prepared by the conventional ingot metallurgy (I/M) process and P/M process were used, I/M material is commercially available. and their corrosion behavior were investigated through the electrochemical tests such as potentiodynamic polarization test, slow rate strain tensile (SSRT) test and electrochemical impedance spectroscopy (EIS) measurement under SSRT test in the corrosion solution and the deionized water.


2019 ◽  
Vol 24 (4) ◽  
pp. 51-58
Author(s):  
Le Hong Quan ◽  
Nguyen Van Chi ◽  
Mai Van Minh ◽  
Nong Quoc Quang ◽  
Dong Van Kien

The study examines the electrochemical properties of a coating based on water sodium silicate and pure zinc dust (ZSC, working title - TTL-VN) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl (SCE) reference electrode in 3 M solution of KCl, auxiliary electrode Pt (8x8 mm) and working electrodes (carbon steel with surface treatment up to Sa 2.5) for determination of corrosion potential (Ecorr) and calculation of equivalent electric circuits used for explanation of impedance measurement results. It was shown that electrochemical method is effective for study of corrosion characteristics of ZSC on steel. We proposed an interpretation of the deterioration over time of the ability of zinc particles in paint to provide cathodic protection for carbon steel. The results show that the value of Ecorr is between -0,9 and -1,1 V / SCE for ten days of diving. This means that there is an electrical contact between the zinc particles, which provides good cathodic protection for the steel substrate and most of the zinc particles were involved in the osmosis process. The good characteristics of the TTL-VN coating during immersion in a 3,5% NaCl solution can also be explained by the preservation of corrosive zinc products in the coating, which allows the creation of random barrier properties.


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