Steel Corrosion and Control in Concrete Made with Seawater

2020 ◽  
Vol 10 (1) ◽  
pp. 58-67
Author(s):  
Arpit Goyal ◽  
S.R. Karade
Keyword(s):  
Compressive Strength ◽  
Electrical Resistivity ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Fly Ash ◽  
Impedance Spectroscopy ◽  
Potable Water ◽  
Electrochemical Impedance ◽  
Half Cell ◽  
Cell Potential

Background: Water scarcity is amongst the biggest problems the world is facing in the 21st century. To reduce the consumption of Potable Water (PW) in construction industries and to make concrete construction more sustainable, its replacement with Seawater (SW) has been explored. Technical literature on this subject is not widely available. Such investigations are necessary for determining suitable remedial measures for the effective utilization of seawater for making sustainable concrete. Objective: In the present study, use of Seawater (SW) has been explored as both mixing and curing water in concrete. To counter the adverse effects of seawater on strength and corrosion resistance, use of Fly Ash (FA) and Red Mud (RM) as cement replacements in the seawater concrete had been investigated. Methods: The possibility of the use of seawater in making concrete has been explored by literature and experimental investigations. The obtained results are discussed in light of the information available in the literature. Various tests were performed such as compressive strength, Half-cell potential, electrochemical impedance spectroscopy and microstructural analysis using SEM and XRD. Result: Results showed higher compressive strength and improved corrosion resistance for Seawater Concrete (SWC) with FA & RM as compared to Potable Water Concrete (PWC) specimens. SWC specimens without supplementary cementitious materials show lower electrical resistivity and potential more negative than -450 mV indicating severe corrosion. 30% FA and 5% RM is identified as the optimum combination for the most favorable response in terms of mechanical strength and electrical resistivity of seawater concrete. After 90 days, the compressive strength of 35.77 MPa was achieved. Conclusion: Combination of both FA and RM in SWC reduces chloride migration and increases chloride binding by the formation of Friedel’s salt. Half-cell potential (HCP) and Electrochemical Impedance Spectroscopy (EIS) results confirmed a reduction in corrosion rate in SWC specimens with fly ash and red mud.

Electrochemical Impedance Spectroscopy (EIS) Study of Nano-Composite Polyurea Coating under the Wet-Dry Cyclic Conditions

2014 ◽  
Vol 789 ◽  
pp. 495-500
Author(s):  
Bing Ying Wang ◽  
Qing Hao Shi ◽  
Wen Long Zhang
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Composite Coating ◽  
Electrochemical Impedance ◽  
Protective Action ◽  
Experimental Result ◽  
Resistance Property ◽  
Corrosion Resistance Property ◽  
Mass Fractions

The polyurea was modified by adding different amounts of nanometer ZnO. The corrosion behavior of polyurea/primer composite coating system in wet-dry cyclic environment of 3.5% NaCl solution was studied by using the Electrochemical Impedance Spectroscopy (EIS) measurement and adhesion test technology. The experimental result showed that, different mass fractions of nanometer ZnO had different influences on the corrosion resistance property of coating. When the mass fraction of nanometer ZnO was 5%, the composite coating had the largest protective action. The corrosion resistance property of nanometer ZnO can be improved by increasing the density of polyurea coating, however, the corrosion resistance property of polyurea coating will be weakened in case of exceeding the critical adding amount.

The effect of electroplating current density on microstructure, corrosion, and wear behavior of Ni–P–W–TiO2 coating

2021 ◽  
Vol 112 (6) ◽  
pp. 474-485
Author(s):  
Sajjad Sadeghi ◽  
Hadi Ebrahimifar
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Micro Hardness ◽  
Aisi 304L

Abstract The use of ceramic particles in the matrix of alloy coatings during the electroplating process has received considerable attention. These particles can create properties such as high corrosion resistance, insolubility, high-temperature stability, strong hardness, and self-lubrication capability. Herein, an Ni–P–W–TiO2 coating was deposited on an AISI 304L steel substrate using the electroplating method. Electroplating was performed at current densities of 10, 15, 20, and 25 mA · cm–2, and the effect of current density on microstructure, corrosion behavior, and wear behavior was investigated. The coatings were characterized by means of scanning electron microscopy. To investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed in a 3.5% NaCl aqueous solution. A pin-on-disk test was conducted to test the wear resistance of uncoated and coated samples. Sample micro-hardness was also measured by Vickers hardness testing. Examination of the microstructure revealed that the best coating was produced at a current density of 20 mA · cm–2. The results of potentiodynamic polarization and electrochemical impedance spectroscopy tests were consistent with microscopic images. The coating created at the current density of 20 mA · cm–2 had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the wear test showed that increasing the current density of the electroplating path up to 20 mA · cm–2 enhances micro-hardness and wear resistance.

scholarly journals Degradation Phenomena of Bismuth-Modified Felt Electrodes in VRFB Studied by Electrochemical Impedance Spectroscopy

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Jonathan Schneider ◽  
Eduard Bulczak ◽  
Gumaa El-Nagar ◽  
Marcus Gebhard ◽  
Paul Kubella ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Impregnation Method ◽  
Carbon Felt ◽  
Half Cell ◽  
Negative Side ◽  
Prolonged Contact ◽  
Before And After

The performance of all-V redox flow batteries (VRFB) will decrease when they are exposed to dynamic electrochemical cycling, but also when they are in prolonged contact with the acidic electrolyte. These phenomena are especially severe at the negative side, where the parasitic hydrogen evolution reaction (HER) will be increasingly favored over the reduction of V(III) with ongoing degradation of the carbon felt electrode. Bismuth, either added to the electrolyte or deposited onto the felt, has been reported to suppress the HER and therefore to enhance the kinetics of the V(II)/V(III) redox reaction. This study is the first to investigate degradation effects on bismuth-modified electrodes in the negative half-cell of a VRFB. By means of a simple impregnation method, a commercially available carbon felt was decorated with Bi 2 O 3 , which is supposedly present as Bi(0) under the working conditions at the negative side. Modified and unmodified felts were characterized electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a three-electrode setup. Surface morphology of the electrodes and composition of the negative half-cell electrolyte were probed using scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (TXRF), respectively. This was done before and after the electrodes were subjected to 50 charge-discharge cycles in a battery test bench. Our results suggest that not only the bismuth catalyst is dissolved from the electrode during battery operation, but also that the presence of bismuth in the system has a strong accelerating effect on electrode degradation.

Corrosion Resistance of a New Cu-Alloy (Low Ni) vis-à-vis Cu-10Ni Alloy in Sulfide Polluted Synthetic Seawater

2012 ◽  
Vol 585 ◽  
pp. 488-492
Author(s):  
Adeeba F. Khan ◽  
Awanikumar P. Patil ◽  
T. Subba Rao
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Accelerated Corrosion ◽  
Synthetic Seawater ◽  
Cu Alloy

Cu-10Ni alloy suffers accelerated corrosion in sulfide polluted seawater. As an alternative, a new single phased, Cu-28%Zn-5%Ni-5%Mn-2%Fe alloy (hereby referred as CNZ-alloy) is developed and tested for the corrosion resistance in clean and sulfide polluted synthetic seawater. The CNZ-alloy showed better corrosion resistance than the standard Cu-10Ni alloy in both the test solutions i.e. clean and sulfide polluted synthetic seawater with . The results are discussed on the basis of polarization and electrochemical impedance spectroscopy. The better corrosion resistance of CNZ-alloy is attributed to the formation of protective ZnS and MnS2 films.

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