scholarly journals Effect of Period of Immersion on Corrosion Potential, Anodic Polarization, and Impedance Characteristics of Reinforced Steel in Mortar (W/C: 0.6)

2016 ◽  
Vol 30 (4) ◽  
pp. 327-333
Author(s):  
Jae-Hyun Jeong ◽  
Kyung-Man Moon ◽  
Sung-Yul Lee ◽  
Myeong-Hoon Lee ◽  
Tae-Sil Baek
Keyword(s):  
Anodic Polarization ◽  
Corrosion Potential ◽  
Impedance Characteristics ◽  
Reinforced Steel

scholarly journals Assessment on Corrosion Damage of Steel Reinforced Concrete Structures of Kathmandu Valley Using Corrosion Potential Mapping Method

2019 ◽  
Vol 15 (2) ◽  
pp. 45-54
Author(s):  
Nav Raj Phulara ◽  
Jagadish Bhattarai
Keyword(s):  
Corrosion Potential ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Corrosion Damage ◽  
Mapping Method ◽  
Kathmandu Valley ◽  
Building Roof ◽  
Steel Reinforced Concrete ◽  
Potential Mapping ◽  
Reinforced Steel

Present study is focused to investigate the corrosion damage conditions of steel reinforced twenty eight different types of the concrete structure samples from Kathmandu valley using a non-destructive technique of the corrosion potential mapping (CPM) method in accordance with ASTM C876-91 Standards. It is found from the present assessment that the building roof of public owners house, hume pipes and building pillars used in Kathmandu valley are generally under the low risk of reinforced steel corrosion in these concrete structures, that is, less than 10 % probability of the corrosion damage, although the fencing pillars and the roof slabs of different office buildings are found to be high risk of reinforced steel corrosion damage, that is, more than 90 % probability of corrosion damage among twenty eight concrete structures.

scholarly journals Damage Mechanisms of Polymer Impregnated Carbon Textiles Used as Anode Material for Cathodic Protection

2018 ◽  
Vol 9 (1) ◽  
pp. 110 ◽  
Author(s):  
Amir Asgharzadeh ◽  
Michael Raupach
Keyword(s):  
Anode Material ◽  
Corrosion Protection ◽  
Influencing Factors ◽  
Cathodic Protection ◽  
Anodic Polarization ◽  
Steel Structures ◽  
Damage Mechanisms ◽  
Environmental Media ◽  
Reinforced Steel

Carbon textiles as anode material for cathodic corrosion protection (CP) have been used in several reinforced steel structures. However, experience with durability is limited. To date, various influencing factors have been discovered and systematic tests on different carbon textiles with different impregnation materials in various environmental media have been carried out and considered the degradation of the impregnation materials. In this work the boundary potentials are determined at which the impregnation and sizing is destroyed under anodic polarization and the damage mechanisms are described.

Characteristics of Inconel 625 Filler Metal Affecting to Weld and Deposited Metal Zones in the Case of Welded to Forged Steel for Piston Crown Material

2014 ◽  
Vol 1004-1005 ◽  
pp. 1114-1119
Author(s):  
Sung Yul Lee ◽  
Kyung Man Moon ◽  
Jong Pil Won ◽  
Jae Hyun Jeong ◽  
Tae Sil Baek
Keyword(s):  
Corrosion Resistance ◽  
Weld Metal ◽  
Base Metal ◽  
Anodic Polarization ◽  
Corrosion Potential ◽  
Filler Metal ◽  
Polarization Curves ◽  
Inconel 625 ◽  
Piston Crown ◽  
Deposited Metal

Recently, wear and corrosion of the engine parts surrounded with combustion chamber is more serious compared to the other parts of the engine due to using of heavy oil of low quality. Therefore, an optimum repair welding for these parts is very important to prolong their lifetime in a economical point of view. In this study, Inconel 625 filler metal was welded with GTAW method in the forged steel which would be generally used with piston crown material. In this case, the mechanical and corrosion properties between weld metal zone (WM) welded to the groove which were artificially made in the base metal and deposited metal zone (DM) only welded by Inconel 625 filler metal on the surface of the base metal were investigated using electrochemical methods, such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% H2SO4 solution. The deposited metal zone exhibited a better corrosion resistance compared to the weld metal zone, furthermore, its corrosion potential was a nobler value rather than that of the weld metal zone. However, the hardness indicated more or less higher value in the weld metal zone. The corrosive products after measurement of anodic polarization curves was hardly observed both in the weld and deposited zones, while, the morphologies of the corroded surfaces exhibited general and pitting corrosion in the weld and deposited metal zones respectively. The fine pearlite microstructure was a little observed in the weld metal zone, moreover, the microstructure of ferrite with elliptical pattern was significantly increased in the deposited metal zone. As a result, it is considered that the amount of Cr, Mo and Ni having a high corrosion resistance diffuse and migrate from the weld metal zone to the base metal zone, thus, the deposited metal zone indicated a better corrosion resistance than the weld metal zone because the amount of Cr, Mo and Ni were much involved in deposited metal zone compared to the weld metal zone.

The Effect of Cover Thickness to Corrosion Characteristics of Reinforced Steel Bar Emedded in Mortar Specimen (W/C:0.6) Aged 5 Years in Seawater

2013 ◽  
Vol 785-786 ◽  
pp. 1176-1180 ◽  
Author(s):  
Sung Yul Lee ◽  
Jong Pil Won ◽  
Dong Hyun Park ◽  
Myeong Hoon Lee ◽  
Kyung Man Moon
Keyword(s):  
Corrosion Resistance ◽  
Polarization Resistance ◽  
Corrosion Potential ◽  
Polarization Curves ◽  
Cyclic Voltammograms ◽  
Economic Point ◽  
Mortar Specimen ◽  
Steel Bar ◽  
Reinforced Steel ◽  
Cover Thickness

Reinforced concrete structures have been increasingly widely used through numerous industrial fields. These structures are often exposed to severely corrosive environments such as sea water, contaminated water, acid rain, and the seashore. Thus, corrosion problems of the steel bars embedded in concrete are very important from a safety and economic point of view. In this study, the effects of cover thickness on the corrosion properties of reinforced steel bar embedded in mortar specimen (W/C:0.6) were investigated using electrochemical methods such as corrosion potentials, polarization curves, cyclic voltammograms, galvanostat and potentiostat. Corrosion potentials shifted to the noble direction, and the value of AC impedance also exhibited a higher value with increasing cover thickness, furthermore, polarization resistance also increased with increasing cover thickness. This is probably that the thinner cover thickness, seawater solution is easy to arrive at embedded steel compared to other thicker cover thickness, so, its steel bar may be easily corroded due to chloride ion, which is resulted in shifting corrosion potential to negative direction, decreasing polarization resistance. Consequently, it is considered that the relation between corrosion resistance of reinforced steel and cover thickness is nearly matched with each other. However, its corrosion resistance estimated by measurement of corrosion potential was not well in agreement with value obtained by polarization curves.

Surfacial Modification of Magnesium-Lithium Alloy

2014 ◽  
Vol 905 ◽  
pp. 113-118
Author(s):  
Hong Jie Luo ◽  
Yi Han Liu ◽  
Bin Na Song ◽  
Guang Chun Yao
Keyword(s):  
Anodic Polarization ◽  
Phosphorus Content ◽  
Corrosion Potential ◽  
Nacl Solution ◽  
Effective Protection ◽  
Nickel Ions ◽  
Lithium Alloy ◽  
Matrix Surface ◽  
The Matrix ◽  
Electroless Ni

A novel process of electroless Ni-P plating on magnesium-lithium alloy is discussed in this paper, by which nickel ions are provided by basic nickel carbonate and a new pretreatment method is introduced to obtain good quality coating. The corrosion behavior of magnesium-lithium alloy without or with coating was compared and the bonding strength of the electroless Ni-P coating to the matrix surface was also measured. The results showed that the process of electroless Ni-P plating can be easily achieved on the intermediate layer and a compact Ni-P coating without flaws is formed synchronously. The thickness of Ni-P coating is above 20 μm and its phosphorus content is about 10.501wt.%. The corrosion potential of magnesium-lithium alloy coated by Ni-P increases obviously (-0.315V) during the anodic polarization in 3.5 wt. % NaCl solution and this phenomenon indicates that an effective protection has been formed for the alloy. It was proved that the Ni-P coating adheres on magnesium-lithium alloy surface tightly through the file test and cross cut test.

An Electrochemical Evaluation of 3003, 3004, and 5050 Aluminum Alloys for Desalination

CORROSION ◽  
1974 ◽  
Vol 30 (2) ◽  
pp. 53-59 ◽  
Author(s):  
R. A. BONEWITZ
Keyword(s):  
Aluminum Alloys ◽  
Anodic Polarization ◽  
Corrosion Potential ◽  
Sea Water ◽  
Polarization Curves ◽  
General Corrosion ◽  
Corrosion Rates ◽  
Electrochemical Evaluation

Abstract Aluminum alloys 3003, 3004, and 5050 were evaluated for desalination applications by means of their anodic polarization curves determined in 1X synthetic sea water at 25 C (77 F) to 150 C (302 F). Pitting performance was established from the relative values of the corrosion potential and the breakdown and protection potentials, and general corrosion rates were calculated from corrosion currents determined by the slop-intercept method. Pitting is not anticipated for 3003 and 3004 alloys at temperatures to 150 C and for 5050 alloy to 125 C (257 F). General corrosion rates for these alloys were less than 1 mpy.

Microstructure, Growth Kinetics, and Corrosion Resistance of Hot-Dip Galvanized Zn-5% Al Coatings

CORROSION ◽  
1991 ◽  
Vol 47 (7) ◽  
pp. 536-541 ◽  
Author(s):  
L. A. Rocha ◽  
M. A. Barbosa
Keyword(s):  
Growth Kinetics ◽  
Immersion Time ◽  
Anodic Polarization ◽  
Corrosion Potential ◽  
Surface Enrichment ◽  
Molten Bath ◽  
Good Adhesion ◽  
Electrochemical Tests ◽  
Deaerated Solution ◽  
Preferential Dissolution

Abstract Several characteristics of Zn-5% A1 coatings—namely microstructure, growth kinetics, and electrochemical behavior—have been studied. A ZnCl2-based flux for the production of Zn-5% Al coatings by a dry hot-dip galvanizing process, developed in this work, produced coatings with good adhesion and without bare spots. The coating thickness is practically independent of the immersion time (between 1 and 600 seconds). The formation of an intermetallic compound on the surface of the steel during the first moments of contact with the molten bath is responsible for this behavior. Electrochemical tests in a 0.1 M NaCl deaerated solution have shown that the corrosion potential is ca. 400 mV anodic in relation to the corrosion potential of the steel and that preferential dissolution of zinc occurs during anodic polarization, resulting in a surface enrichment of aluminum.

Corrosion by Alternating Current: A Study of the Anodic Polarization of Mild Steel in Na2SO4 Solution

CORROSION ◽  
1979 ◽  
Vol 35 (11) ◽  
pp. 514-523 ◽  
Author(s):  
D-T. CHIN ◽  
T-W. FU
Keyword(s):  
Mild Steel ◽  
Electric Current ◽  
Current Density ◽  
Anodic Polarization ◽  
Corrosion Potential ◽  
Alternating Current ◽  
Chloride Ions ◽  
Time Averaging ◽  
Mixed Potential ◽  
Averaging Analysis

Abstract A study has been made of the anodic polarization of mild steel in Na2SO4 solutions (pH 3-9) in the presence of a sinusoidal electric current. The measurement was carried out over a range of alternating current (AC) densities from 0 to 200 mA/c2 and AC frequencies from 20 to 6000 Hz. It was found that the corrosion potential of mild steel shifted toward the active direction in the presence of AC. The magnitude of the potential shift increased with increasing AC densities, and decreased with AC frequencies. AC also increased the passivity current density in a way similar to the addition of chloride ions to the electrolyte. The phenomenon was explained with a time-averaging analysis of the mixed potential theory.

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