scholarly journals Experimental Analysis of Reinforcement Rust in Cement under Corrosive Environment

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 241
Author(s):  
Xiaozhen Li ◽  
Hui Wang ◽  
Jianmin Wang ◽  
Junzhe Liu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Steel Corrosion ◽  
Corrosion Products ◽  
Chloride Salt ◽  
Corrosive Environment ◽  
Cement Slurry ◽  
Passivation Film ◽  
Chloride Environment ◽  
Corrosive Environments ◽  
Structural Layer

In this work, the microstructure characteristics of corrosion products of reinforcement under a corrosive environment with chloride, carbonation and the combination of chloride-carbonization were studied by x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy/energy spectroscopy (SEM-EDX). The results indicate that the outside of the passivation film reacts with the cement slurry to produce Fe–SiO4 in all three corrosive environments. The inner side is not completely corroded. The morphology of the corrosion is different in the three environments. In a chloride environment, corrosion products have obvious cracks, and the local layered structure is dense. In a carbonation environment, the surface of the steel corrosion shows a uniform granular structure and loose texture. With the combination of chloride and combination, the surface of the structural layer of steel corrosion was uneven and accompanied by protrusions, cracking and spalling occurred. The composition of the corrosion substances in the three corrosion environments are mainly composed of FeO, Fe3O4, Fe2O3 and Fe–SiO4. The content of iron oxide increases from a chloride salt, carbonization to the composite environment, indicating that the corrosion degree intensifies successively.

scholarly journals Chemical Composition of Corrosion Products of Rebar Caused by Carbonation and Chloride

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jundi Geng ◽  
Junzhe Liu ◽  
Jiali Yan ◽  
Mingfang Ba ◽  
Zhimin He ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Corrosion Products ◽  
Chloride Salt ◽  
Oxide Content ◽  
Passivation Film ◽  
Steel Bar ◽  
Steel Bars ◽  
Main Components ◽  
Corrosion Of Steel ◽  
Peak Value

The microstructures of steel bars were studied by X-ray photoelectron spectroscopy (XPS), and the mechanism of corrosion of steel bars under the corrosion factors was elucidated. The results show that the passivation film and corrosive surface of the steel surface in the solution of the chloride-containing salt were coarser and the surface state was denser. The main corrosion products are FeOOH and FeO. The surface of the steel immersed in the simulated carbonized solution had loose pores. The main components are FeOOH, Fe3O4, and Fe2O3. The surface of the steel bar has a large amount of yellowish brown corrosion products in the simulated carbonization and chloride salt. The surface of the corrosion products was stripped and the main components are FeOOH, Fe3O4, and FeCl3, where the content of FeOOH is as high as 60%. The peak value of iron is gradually increased from the simulated chloride salt solution to the carbonized solution to the combined effect of carbonation and chloride salt; the iron oxide content is increased and corrosion of steel is obviously serious.

scholarly journals Influence of Rust Inhibitor on the Corrosion Resistance of Reinforcement in Cement Paste with Chloride

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 606
Author(s):  
Linchun Zhang ◽  
Ailian Zhang ◽  
Ke Li ◽  
Qian Wang ◽  
Junzhe Liu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Cement Paste ◽  
Photoelectron Spectroscopy ◽  
Electrical Resistance ◽  
Corrosion Properties ◽  
Passivation Film ◽  
Steel Bars ◽  
Assembly Unit ◽  
Chloride Environment ◽  
Rust Inhibitor

The electrical resistance and polarization effect of cement paste containing reinforcement were tested to research the anti-corrosion properties of steel bars in cement paste. Moreover, the microstructure and composition of passivation film and rust on the steel bars were studied. The water–cement ratio of the cement paste in this study was 0.3, with 0.5% NaCl, 1% NaNO2, and 1% Benzotriazole, and an assembly unit of 0.5% NaNO2 + 0.5% Benzotriazole by mass of cement was added to the cement to provide a chloride environment. X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were applied to research the composition of the passivation film and the microstructure of the cement paste, respectively. The results indicated that the samples with the assembly unit of 0.5% NaNO2 + 0.5% Benzotriazole showed the highest electrical resistance and polarization electrical resistance, while the specimens with 1.0% Benzotriazole showed the lowest electrical resistance and polarization electrical resistance. Moreover, the passivation film of steel bars weakened with increasing distance from the surface of the steel bars. Therefore, the corrosion of steel bars becomes more serious with increasing distance. Finally, the influence of the rust inhibitor on the corrosion resistance of steel bars in the specimens decreased in the following order: 0.5% NaNO2 + 0.5% Benzotriazole >1.0% NaNO2>1.0% Benzotriazole.

scholarly journals Effect of Additional Sulfide and Thiosulfate on Corrosion of Q235 Carbon Steel in Alkaline Solutions

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Bian Li Quan ◽  
Jun Qi Li ◽  
Chao Yi Chen
Keyword(s):  
Carbon Steel ◽  
Photoelectron Spectroscopy ◽  
Steel Corrosion ◽  
Corrosion Products ◽  
Alkaline Solutions ◽  
Corrosion Mechanism ◽  
Surface Cracks ◽  
Weight Loss Method ◽  
Q235 Carbon Steel ◽  
Loss Method

This paper investigated the effect of additional sulfide and thiosulfate on Q235 carbon steel corrosion in alkaline solutions. Weight loss method, scanning electron microscopy (SEM) equipped with EDS, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements were used in this study to show the corrosion behavior and electrochemistry of Q235 carbon steel. Results indicate that the synergistic corrosion rate of Q235 carbon steel in alkaline solution containing sulfide and thiosulfate is larger than that of sulfide and thiosulfate alone, which could be due to redox reaction of sulfide and thiosulfate. The surface cracks and pitting characteristics of the specimens after corrosion were carefully examined and the corrosion products film is flake grains and defective. The main corrosion products of specimen induced by S2−and S2O32-are FeS, FeS2, Fe3O4, and FeOOH. The present study shows that the corrosion mechanism of S2−and S2O32-is different for the corrosion of Q235 carbon steel.

Leaching of Am-241 from a Radioactive Waste Glass Corroded in the Presence of Stainless Steel Corrosion Products and/or Bentonite

1987 ◽  
Vol 112 ◽  
Author(s):  
Masaki Tsukamoto ◽  
Inga-Kari Björner ◽  
Hilbert Christensen ◽  
Hans-Peter Hermansson ◽  
Lars Werme
Keyword(s):  
Stainless Steel ◽  
Radioactive Waste ◽  
Mass Loss ◽  
Total Mass ◽  
Corrosion Behaviour ◽  
Steel Corrosion ◽  
Waste Glass ◽  
Corrosion Products ◽  
Total Mass Loss ◽  
Elemental Mass

AbstractThe release of Am-241 during corrosion of the radioactive waste glass, JSS-A, has been studied in the presence of corrosion products and/or uncom-pacted bentonite. The corrosion behaviour of Am-241 has been analyzed using gamma spectrometry. Adsorption of Am-241 on bentonite is observed in all cases. The contents of Am-241 in centrifuged leachates are in most cases less than 1/100 of total values. The normalized elemental mass loss of Am increases initially with corrosion time, and the values in the presence of bentonite and corrosion products are larger than those in the presence of bentonite alone. This tendency is in agreement with results previously found for other elements. The release of Am is low, only about 10–20 % of the corresponding total mass loss.

scholarly journals XANES-Based Determination of Redox Potentials Imposed by Steel Corrosion Products in Cement-Based Media

2018 ◽  
Author(s):  
Bin Ma ◽  
Alejandro Fernandez-Martinez ◽  
Benoît Madé ◽  
Nathaniel Findling ◽  
Ekaterina Markelova ◽  
...  
Keyword(s):  
Steel Corrosion ◽  
Corrosion Products ◽  
Redox Potentials

A study of the corrosion of polymethyl methacrylate coated rebar using glancing angle X-ray absorption near edge spectroscopy

CORROSION ◽  
10.5006/3912 ◽  
2021 ◽  
Author(s):  
Arthur Situm ◽  
Xiaoxuan Guo ◽  
Burke Barlow ◽  
Bao Guo ◽  
Ian Burgess ◽  
...  
Keyword(s):  
Polymethyl Methacrylate ◽  
Polymer Coating ◽  
Steel Corrosion ◽  
Corrosion Products ◽  
Thin Layers ◽  
Fluorescence Signal ◽  
X Rays ◽  
X Ray ◽  
Glancing Angle ◽  
X Ray Absorption

Polymer coatings can be used to mitigate the corrosion of steel in high chloride environments. Obtaining speciation information from thin corrosion layers can be important for understanding corrosion mechanisms, including polymer coating failure. This study outlines the effectiveness of collecting glancing angle X-ray absorption near edge spectroscopy (GA-XANES) spectra at the Fe K-edge to obtain chemical speciation information at the polymer-steel interface without removal of the polymer film. The depth of penetration of the incident X-rays can be altered by changing the incidence angle, allowing for more fluorescence signal from corrosion products to be detected relative to the Fe metal fluorescence signal in GA-XANES spectra. This study demonstrates the use of GA-XANES to study thin layers of steel corrosion and obtain depth profile information of steel corrosion products beneath a polymethyl methacrylate polymer coating.

Influence of nitrite on chemical composition of passivation film of steel bars under the coupling effects of carbonization and chloride

2019 ◽  
Vol 66 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Junzhe Liu ◽  
Jundi Geng ◽  
Hui Wang ◽  
Mingfang Ba ◽  
Zhiming He
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Chloride Solution ◽  
Layer Structure ◽  
Coupling Effects ◽  
Content Type ◽  
X Ray ◽  
Passivation Film ◽  
Steel Bars ◽  
Micro Structures

Purpose This paper aims to study the influence of NaNO2 on the chemical composition of passivation film. Design/methodology/approach X-ray photoelectron spectroscopy and X-ray diffraction were selected to determine the composition of passivation film of steel bars in mortar. The specimens were exposed to the chloride solution, carbonation environment and the coupling effects of chloride solution and carbonation. The chemical composition and micro structures at 0 and 5 nm from the outer surface of the passivation film of steel bars were analyzed. Findings Results showed that the nitrite inhibitor improved the forming rate of the passivation film and increased the mass ratio of Fe3O4 to FeOOH on the surface of steel bars. The component of Fe3O4 at 5 nm of the steel passivation film was more than that at 0 nm. Sodium ferrite in the pore solution was easily hydrolyzed and then FeOOH was formed. Therefore, due to the nitrite inhibitor, a “double layer structure” of the passivation film was formed to prevent steels bars from corrosion. Originality/value This is original work and may help the researchers further understand the mechanism of rust resistance by nitrite inhibitor.

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