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.

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.

Effects of alternating stray current on the corrosion behaviours of buried Q235 steel pipelines

2017 ◽  
Vol 64 (6) ◽  
pp. 599-606 ◽  
Author(s):  
Yanbao Guo ◽  
Hai Tan ◽  
Deguo Wang ◽  
Tao Meng
Keyword(s):  
Corrosion Rate ◽  
Current Density ◽  
Corrosion Potential ◽  
Rapid Development ◽  
Geometrical Shape ◽  
Uniform Corrosion ◽  
Negative Deviation ◽  
Stray Current ◽  
Content Type ◽  
Ac Current

Purpose With the rapid development of rail transportation and energy-delivery systems, such as buried oil and gas pipelines and high-voltage transmission lines, the alternating current (AC) corrosion of buried steel pipelines is becoming more serious. This paper aims to study the corrosion behaviours of Q235 buried steel pipelines induced by the alternating stray current, with a set of indoor simulated experiment apparatuses. Design/methodology/approach The corrosion of the coating holidays of the buried steel pipelines at various AC current densities from 0 to 200 A/m2 in the soil-simulating environment was revealed by the electrochemical and weight-loss methods. Findings The results showed that the corrosion potential of the steel shifted negatively obviously and the corrosion rate of the steel increased with the increasing of AC current density. At a low AC current density, the negative deviation of the corrosion potential of the steel was small and the increase of corrosion rate was slight. However, the negative deviation of the corrosion potential was remarkable and the corrosion rate was greatly increased at a relative higher AC current density. The geometrical shape of the corrosion images indicated the corrosion forms changed from uniform corrosion to local corrosion due to the increase of AC interference. Originality/value Investigation results are of benefit to provide a new strategy to forecast and evaluate the AC-induced corrosion of the buried pipelines which could improve the safety of pipeline transportation.

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.

scholarly journals Test on Durability of Shield Tunnel Concrete Segment under Coupling Multi-Factors

2014 ◽  
Vol 8 (1) ◽  
pp. 451-457 ◽  
Author(s):  
Qiang Li ◽  
Hongfa Yu ◽  
Haiyan Ma ◽  
Shudong Chen ◽  
Shuguang Liu
Keyword(s):  
Steel Corrosion ◽  
Lower Surface ◽  
Chloride Ions ◽  
Shield Tunnel ◽  
Chloride Salt ◽  
Stray Current ◽  
Power Simulation ◽  
Dc Power ◽  
Chlorine Ions ◽  
Chlorine Ion

To study the durability of shield tunnel concrete segment under coupling multi-factors, the durability and degradation law of reinforced concrete segments under the joint action of carbonation, sulfate, chloride salt and stray current was studied by accelerated environmental and direct current (DC) power simulation test. The results show that the presence of the stray current not only accelerates the migration of chloride ions to the concrete, but also makes chlorine ion gradually converge to the steel surface. The steel corrosion near the corrosion solution on the up surface of segment is more serious than the steel corrosion near the carbon dioxide on the lower surface. The interaction of chlorine ions and stray current primarily controls the durability of the segment.

Corrosion rate of carbon steel under synergistic effect of seawater parameters including pH, temperature, and salinity in turbulent condition

2013 ◽  
Vol 31 (3-6) ◽  
pp. 135-144 ◽  
Author(s):  
Alisina Toloei ◽  
Sanam Atashin ◽  
Mahmood Pakshir
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Fluid Velocity ◽  
Steel Corrosion ◽  
Affecting Factors ◽  
Effective Parameters ◽  
Simultaneous Effect ◽  
Experimental Media ◽  
Aisi 1045 ◽  
Combined Action

AbstractThe variation of AISI 1045 carbon steel corrosion rate in seawater is investigated under the simultaneous effect of marine parameters in both stagnant and turbulent conditions. The combined effect of salinity, velocity, pH, and temperature is studied using two-by-two graphical curves, while each parameter is applied at three levels. The possible influence of simultaneously acting factors on each considering parameter is experimentally studied and explained using theoretical basis. This paper offers an advantage of considering the simultaneous effect of parameters instead of individual ones, which simulate the experimental media close to the real in-site marine environment where all the affecting factors act in a combined manner. The most innovation of this study is two-by-two investigation of combined action of effective parameters on corrosion rate, which is much more comprehensive and detailed compared to previous researches. Every parameter is considered at three ranges and all the possible interactions with other factors are taken into account. It is proven that the effect of considered parameters on the rate of corrosion is the function of other simultaneously acting factors. The role of fluid velocity condition and also the reaction polarization status is found to be pronounced.

Ellipsometric-Potentiostatic Studies of Steel Corrosion: Oxide Film Development and Effects of Inhibitors

CORROSION ◽  
1971 ◽  
Vol 27 (8) ◽  
pp. 315-319 ◽  
Author(s):  
B. J. BORNONG ◽  
P. MARTIN
Keyword(s):  
Corrosion Rate ◽  
Anodic Polarization ◽  
Steel Corrosion ◽  
Chloride Ion ◽  
Surface Roughening ◽  
Anodic Films ◽  
Buffer Solutions ◽  
Adsorbed Films ◽  
Bare Steel ◽  
Film Development

Abstract Simultaneous ellipsometric-potentiostatic measurements were used to study film development on mild steel in borate-boric acid buffer solutions at pH 7.4, with and without 0.005M and 0.0025M KCl. Effects of pre-adsorbed films of barium dinonylnaphthalene sulfonate were also determined. Coulometric and ellipsometric film thicknesses of the anodic films agreed reasonably well. Discrepancies increased when pitting occurred because of surface roughening. Chloride ion reduced the passive range and caused increased corrosion at a lower potential. Pre-adsorbed sulfonate films desorbed rapidly under anodic polarization, but were stable for 0.1 to 0.2 volt cathodic. The initial corrosion rate for the bare steel, determined by the Tafel extrapolation and linear polarization methods, was 4 mpy. The pre-adsorbed sulfonate film reduced the corrosion rate to 1 mpy.

scholarly journals Atmospheric Corrosion Behavior of Carbon Steel and Galvanized Steel after Exposure in Eretan and Ciwaringin, West Java Province, Indonesia

2020 ◽  
Vol 20 (5) ◽  
pp. 1032
Author(s):  
Gadang Priyotomo ◽  
Lutviasari Nuraini ◽  
Siska Prifiharni ◽  
Ahmad Royani ◽  
Sundjono Sundjono ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Chloride Ion ◽  
Galvanized Steel ◽  
Uniform Corrosion ◽  
Corrosion Attack ◽  
West Java ◽  
Corrosion Rates ◽  
Weight Loss Method

The investigation of corrosion for carbon steel and galvanized steel has been conducted in the marine atmosphere of Eretan and Ciwaringin Districts, West Java Province. The exposure time of the field test was up to 200 days, and their corrosion rates are determined according to weight loss method. The objective of the work is to elucidate the corrosion behavior of those alloys which is affected by distances from coastline and environmental condition. The magnitude of corrosion rate for carbon steel was 20 times as high as that for galvanized steel in both districts The distance from coastline has significantly affected for the magnitude of corrosion rate, where that both alloys in Ciwaringin is lower than that in Eretan. The deposition of chloride ion in Eretan and Ciwaringin Districts were 4.305 mg/m2 day and 1.863 mg/m2 day, respectively, where the higher chloride ion can tend to increase the corrosion rates. Relative humidity (RH) which is over 60% has essential role for corrosion process as well as rainfall. The uniform corrosion attack was observed both alloys after exposure. The corrosion product phases of galvanized steel exhibits as zincite, hydrozincite and simonkolleite in Eretan as the typical coastline atmosphere phases but not in Ciwaringin. The formation of rust product for both metals lead the decrease of further corrosion attack due to the barrier between metal and environment. The usage of galvanized steel is remarkable to minimize corrosion attack compared to that of carbon steel in tropical coastline.

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.

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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