The Calculation of the Thickness for Uniform Corrosion and Localized Corrosion in Steel Corrosion

2011 ◽  
Vol 255-260 ◽  
pp. 514-518
Author(s):  
Zheng Yi Kong ◽  
Shan Hua Xu ◽  
Yu Sheng Chen
Keyword(s):  
Corrosion Rate ◽  
Constant Temperature ◽  
Safety Assessment ◽  
Steel Corrosion ◽  
Localized Corrosion ◽  
Power Relationship ◽  
Uniform Corrosion ◽  
Experiment Data ◽  
Temperature And Humidity ◽  
Corrosion Pits

Because of the complexity of corrosion, the law of uniform corrosion and localized corrosion is still not clear,so it is difficult to assess their impact on the structure safety. In order to differ them and find their own law, we obtain a lot of corrosion specimens by ways of constant temperature and humidity, and then detect the size of corrosion pits by roughness tester. After that, the method for calculating the thickness of uniform corrosion and localized corrosion is proposed. Then the method is used to analyze the experiment data. The result indicates the thickness of uniform corrosion and localized corrosion all increase with the rate of corrosion, and they all show a power relationship with corrosion rate, so it will provide a basis for distinguishing them in safety assessment.

scholarly journals Investigation of Corrosion Rate and Rust Expansion Form of Segment Reinforcement for Shield Tunnel by Combined Action of Soil Loading, Chloride Ion and Stray Current

2021 ◽  
Vol 13 (6) ◽  
pp. 3444
Author(s):  
Zheng Li ◽  
Hao Jin ◽  
Shuo Yu
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Chloride Ion ◽  
Shield Tunnel ◽  
Uniform Corrosion ◽  
Stray Current ◽  
Soil Loading ◽  
Capacity Degradation ◽  
Expansion Form ◽  
Combined Action

Segment reinforcement corrosion can cause bearing-capacity degradation of shield tunnel, which is unsafe for the metro operation. Therefore, a three-dimensional computational model was proposed in this paper to study the corrosion rate and rust expansion form of segment reinforcement by the combined action of soil loading, chloride ion and stray current. The results show that the arch waist segment steel corrosion rate in the middle is larger than the ends. The rust expansion form of segment reinforcement appears be an eccentric circle. The radius size and circular center are related to the non-uniform corrosion coefficient and the maximum corrosion current density.

scholarly journals Pengaruh variasi pembagian jumlah anoda dengan pola horisontal terhadap laju korosi baja SS400 pada media air laut

2018 ◽  
Vol 8 (1) ◽  
pp. 14
Author(s):  
A. Faisol ◽  
S. Sumarji ◽  
G. Djatisukamto
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Uniform Distribution ◽  
Corrosion Protection ◽  
Average Rate ◽  
Steel Corrosion ◽  
Potential Difference ◽  
Uniform Corrosion ◽  
Sacrificial Anode ◽  
Average Value

Sacrificial anode protection is one type of corrosion protection used to inhibit corrosion rate. The sacrificial anode protection works by utilizing the potential difference between anode and cathode. This research aims to determine the effect of variation in the distribution of quantities and distribution of sacrificial anode aluminum to SS400 steel corrosion rate. The method of calculating the corrosion rate used is the weight loss test. The results of this test indicate that the more uniform distribution of the anode on the surface of the cathode the better the resulting protection will be. The best protection is produced by 4 pieces of sacrificial anode size of 0,5 x 4 cm with an average rate of corrosion rate of 0,1067 mm/year. Protection with 2 pieces of sacrificial anode size 1 x 4 cm resulted in corrosion rate with average value 0,1462 mm/year, while on protection of 1 victim anode with size 2 x 4 cm can produce protection with average value of corrosion rate 0,1677 mm/year. Equivalent distribution of numbers and distributed anodes can narrow the distance between the anodes so that the value of the material's resitivity is smaller and the electrons can be distributed evenly over the entire cathode surface.The corrosion that occurs in SS400 steel is a kind of uniform corrosion. It is seen from the size of the cavity that occurs on each side of the specimen after the immersion process.

The Fractal Character of Corrosion Steel Surface

2010 ◽  
Vol 163-167 ◽  
pp. 3150-3155 ◽  
Author(s):  
Zheng Yi Kong ◽  
Shan Hua Xu
Keyword(s):  
Fractal Dimension ◽  
Safety Assessment ◽  
Surface Characterization ◽  
Fractal Theory ◽  
Steel Corrosion ◽  
Steel Structure ◽  
Sample Length ◽  
Fractal Character ◽  
Corrosion Pits

In this paper, the corrosion specimens are obtained by ways of constant temperature and humidity ,and the size of corrosion pits is detected by roughness tester. So surface characterization of steel corrosion is researched by fractal theory and it has been proved by structure function that it has the fractal character. It find that the fractal dimension is inherent and it will not change with the sample length. The result indicates that the fractal dimension is decreasing with the corrosion rate increasing. so it will help to solve the difficult of safety assessment for In-service steel structure.

scholarly journals Analysis of Temperature Variations, Types of Insulation and Coating on Corrosion Under Insulation on ASTM A53 Pipes

2021 ◽  
Vol 2 (1) ◽  
pp. 110-118
Author(s):  
Reza Putra ◽  
Muhammad Muhammad ◽  
T Hafli ◽  
Nurul Islami ◽  
Arpan Apandi S
Keyword(s):  
Corrosion Rate ◽  
Ph Value ◽  
Test Method ◽  
Localized Corrosion ◽  
Test Time ◽  
Pipe Material ◽  
Uniform Corrosion ◽  
Temperature Variations ◽  
C 50 ◽  
Corrosion Under Insulation

Corrosion Under Insulation (CUI) can be described as localized corrosion that forms as a result of the penetration of water or moisture through an insulating material. The pipe material used is of the ASTM A53 standard and the fluid used in seawater because almost all industries are located on the coast. This type of coating is carried out on the test pipe using Meiji Epoxy Filler. The test method is carried out by flowing seawater fluid in pipes with water temperature variations of 30°C, 50°C, and 70°C. This pipe varies the type of insulation by using glasswool and Rockwool (ASTM G 189-07). This insulation is conditioned in a wet state by giving 2 ml of seawater drops with a pH value of 4 per 6 hours. The test equipment is divided into 3 series according to temperature variations with 4 test specimens and 2 coating variations respectively. The test time was carried out for 336 hours to obtain the corrosion rate results using the ASTM G31-72 weight loss method. The results showed that the type of Glasswool insulation with specimens coated had the lowest corrosion rate value of 0.00483 mmpy at a temperature of 30°C when compared to the same type of treatment on Rockwool insulation of 0.00724 mmpy or an increase of 2.41 times. This study shows that the type of insulation, temperature variation, and coating greatly affect the rate of corrosion and the type of corrosion that occurs is uniform corrosion.

scholarly journals Pengaruh variasi pembagian jumlah anoda dengan pola horisontal terhadap laju korosi baja SS400 pada media air laut

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Ahmad Faisol ◽  
S. Sumarji ◽  
G. Djatisukamto
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Uniform Distribution ◽  
Corrosion Protection ◽  
Average Rate ◽  
Steel Corrosion ◽  
Potential Difference ◽  
Uniform Corrosion ◽  
Sacrificial Anode ◽  
Average Value

Sacrificial anode protection is one type of corrosion protection used to inhibit corrosion rate. The sacrificial anode protection works by utilizing the potential difference between anode and cathode. This research aims to determine the effect of variation in the distribution of quantities and distribution of sacrificial anode aluminum to SS400 steel corrosion rate. The method of calculating the corrosion rate used is the weight loss test. The results of this test indicate that the more uniform distribution of the anode on the surface of the cathode the better the resulting protection will be. The best protection is produced by 4 pieces of sacrificial anode size of 0,5 x 4 cm with an average rate of corrosion rate of 0,1067 mm/year. Protection with 2 pieces of sacrificial anode size 1 x 4 cm resulted in corrosion rate with average value 0,1462 mm/year, while on protection of 1 victim anode with size 2 x 4 cm can produce protection with average value of corrosion rate 0,1677 mm/year. Equivalent distribution of numbers and distributed anodes can narrow the distance between the anodes so that the value of the material's resitivity is smaller and the electrons can be distributed evenly over the entire cathode surface.The corrosion that occurs in SS400 steel is a kind of uniform corrosion. It is seen from the size of the cavity that occurs on each side of the specimen after the immersion process.

scholarly journals Macrocell Corrosion of Steel in Concrete under Carbonation, Internal Chloride Admixing and Accelerated Chloride Penetration Conditions

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7691
Author(s):  
Zhilu Jiang ◽  
Siyao Li ◽  
Chuanqing Fu ◽  
Zheng Dong ◽  
Xuefeng Zhang ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Steel Corrosion ◽  
Chloride Penetration ◽  
Localized Corrosion ◽  
Geometrical Parameters ◽  
Correction Coefficient ◽  
Two Dimensional ◽  
Steel Bar ◽  
Corrosion Of Steel ◽  
Macrocell Corrosion

Steel corrosion has become the main reason for the deterioration of reinforced concrete structures. Due to the heterogeneity of concrete and the spatial variation of environmental conditions, macrocell corrosion is often formed by localized corrosion, which is more detrimental if the anode is supported by large numbers of cathodes. The macrocell corrosion caused by concrete carbonation has been seldom studied. Furthermore, the influence of geometrical conditions on cathode-controlled corrosion in the chloride environment needs to be further clarified. In this work, the macrocell corrosion of steel embedded in concrete specimens exposed to accelerated carbonation, chloride contamination, and chloride penetration is studied using a modified ASTM G109 method. Concrete specimens with various binder types, geometrical parameters (i.e., concrete cover thickness and the diameter of embedded steel), and boundary conditions were tested. A simplified mathematical model for the prediction of the steel corrosion rate was developed considering two-dimensional oxygen diffusion. The results showed that, at the same level of anodic potential drops, the corrosion current rate in chloride-induced corrosion is higher than that of carbonation-induced corrosion. Chloride contamination is less detrimental to concrete incorporated with slag and pulverized fly ash than it is to pure ordinary Portland cement (OPC), likely due to enhanced chloride binding capacity. The results also indicated that the model considering two-dimensional diffusion can accurately predict the cathodic reaction process on corroded steel bars, which provides a theoretical basis for considering the correction coefficient of steel bar position in the establishment of a steel bar corrosion rate model.

The Surface Properties of Corrosion Specimens

2011 ◽  
Vol 255-260 ◽  
pp. 509-513
Author(s):  
Shan Hua Xu ◽  
Zheng Yi Kong ◽  
Chao Zhang
Keyword(s):  
Fractal Dimension ◽  
Safety Assessment ◽  
Surface Characterization ◽  
Fractal Theory ◽  
Steel Structure ◽  
The Other ◽  
Localized Corrosion ◽  
Specimen Surface ◽  
Power Relationship ◽  
Natural Corrosion

The characterstics of corrosion is important to asseess structure safety, however, because of the complexity of corrosion, it is hard to see papers anout it. In order to study the characterstics of corrosion specimen surface, two methods are used to obtain corrosion specimens, one method is constant temperature and humidity, the other is natural corrosion. Then roughness tester is used to detect the profile of corrosion specimen surface, and the surface characterization is analyzed by fractal theory. Through the experimnet, we find the law of power relationship between fractal dimension and the depth of localized corrosion, so it will help to solve the difficulty of safety assessment for in-service steel structure.

scholarly journals Electrochemical metrics for corrosion resistant alloys

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Clara Nyby ◽  
Xiaolei Guo ◽  
James E. Saal ◽  
Szu-Chia Chien ◽  
Angela Y. Gerard ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Current Density ◽  
Crevice Corrosion ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Pitting Potential ◽  
Corrosion Resistant ◽  
High Entropy

AbstractCorrosion is an electrochemical phenomenon. It can occur via different modes of attack, each having its own mechanisms, and therefore there are multiple metrics for evaluating corrosion resistance. In corrosion resistant alloys (CRAs), the rate of localized corrosion can exceed that of uniform corrosion by orders of magnitude. Therefore, instead of uniform corrosion rate, more complex electrochemical parameters are required to capture the salient features of corrosion phenomena. Here, we collect a database with an emphasis on metrics related to localized corrosion. The six sections of the database include data on various metal alloys with measurements of (1) pitting potential, Epit, (2) repassivation potential, Erp, (3) crevice corrosion potential, Ecrev, (4) pitting temperature, Tpit, (5) crevice corrosion temperature, Tcrev, and (6) corrosion potential, Ecorr, corrosion current density, icorr, passivation current density, ipass, and corrosion rate. The experimental data were collected from 85 publications and include Al- and Fe-based alloys, high entropy alloys (HEAs), and a Ni-Cr-Mo ternary system. This dataset could be used in the design of highly corrosion resistant alloys.

Test and Study on Impact of Corrosion on Bond Force between Steel and Concrete

2010 ◽  
Vol 36 ◽  
pp. 176-181
Author(s):  
Xian Feng He ◽  
Shou Gang Zhao ◽  
Yuan Bao Leng
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Rate ◽  
Concrete Structure ◽  
Steel Corrosion ◽  
Reinforced Concrete Structure ◽  
Bond Force ◽  
Steel Bars ◽  
Protection Layer ◽  
Corrosion Of Steel ◽  
The Impact

The corrosion of steel will have a bad impact on the safety of reinforced concrete structure. In severe cases, it may even be disastrous. In order to understand the impact of steel corrosion on the structure, tests are carried out to study corrosion and expansion rules of steel bars as well as the impact rules of corrosion on bond force between steel and concrete. The results show that wet and salty environment will result in steel corrosion; relatively minor corrosion will not cause expansion cracks of protection layers; when steel rust to a certain extent, it will cause cracks along the protection layer; when there exists minor corrosion in steel and the protection layer does not have expansion cracks, the bond force is still large and rapidly decreases as the corrosion rate increases.

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