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.

Preparation and characterization of a cerium conversion film on magnesium alloy

2015 ◽  
Vol 62 (4) ◽  
pp. 253-258 ◽  
Author(s):  
Jie Sun ◽  
Gang Wang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Photoelectron Spectroscopy ◽  
Corrosion Current ◽  
Treatment Temperature ◽  
Conversion Coating ◽  
Conversion Coatings ◽  
Content Type ◽  
X Ray ◽  
Passivation Film

Purpose – The purpose of this paper was to prepare the cerium-based conversion coating on AZ91D magnesium alloy, and its compositions, micro-morphology, corrosion resistance and the chemical valence state of the film elements were investigated. Design/methodology/approach – The methodology comprised preparation of coatings at different temperatures, which then were characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, an electrochemistry workstation and by means of X-ray photoelectron spectroscopy. Findings – The conversion coating had a micro-cracked morphology. The conversion coatings were composed of MgO (or Mg-OH), CeO2 and Ce2O3. The best corrosion resistance of the cerium passivation film appeared when the treatment temperature was about 35°C. Originality/value – The corrosion current densities of conversion coatings were lower by one to two orders of magnitude than the corrosion current density of the blank sample. The rare earth passivation coating prepared under the best condition could reduce the corrosion current to 3.548 × 10−6 A/cm2.

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.

High Temperature Oxidation Behavior of SUS310S Austenitic Stainless Steel

2014 ◽  
Vol 941-944 ◽  
pp. 212-215
Author(s):  
Tao Zheng ◽  
Jing Tao Han
Keyword(s):  
Photoelectron Spectroscopy ◽  
Oxidation Behavior ◽  
Layer Structure ◽  
Energy Dispersive Spectrometer ◽  
Austenitic Stainless Steels ◽  
Temperature Oxidation ◽  
X Ray ◽  
High Temperature Oxidation Behavior ◽  
High Oxidation Resistance ◽  
Ray Diffusion

The oxidation behavior of SUS310S austenitic stainless steels was studied in isothermal conditions at different temperatures between 800oC and 1100oC for 96h in air. The oxidation kinetics was analyzed, the surface and cross-section of the oxide scale grown by oxidation were characterized by using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffusion (XRD) and X-ray photoelectron spectroscopy (XPS). The SUS310S steel has high oxidation resistance at 800oC and with the increase of the temperature, the parabolic rate constants is constantly increasing. Examination of the morphology and composition of oxide layers reveals a double-layer structure, The inner layer is mainly chromium oxide (Cr2O3) and is covered by an uneven thinness outer layer of manganese-chromium or iron-chromium spinel oxide.

scholarly journals Depth Profiling of the Chemical Composition of Free-Standing Carbon Dots Using X-ray Photoelectron Spectroscopy

2018 ◽  
Vol 122 (26) ◽  
pp. 14889-14897 ◽  
Author(s):  
Irene Papagiannouli ◽  
Minna Patanen ◽  
Valérie Blanchet ◽  
John D. Bozek ◽  
Manuel de Anda Villa ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
Depth Profiling ◽  
Free Standing ◽  
X Ray

The influence of Ni on the microstructure and corrosion resistance of high-strength low alloy steel in the Cl-containing environment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dan Wang ◽  
Qingdong Zhong ◽  
Jian Yang ◽  
Shujian Zhang
Keyword(s):  
Corrosion Resistance ◽  
Alloy Steel ◽  
Photoelectron Spectroscopy ◽  
Hsla Steel ◽  
Electrochemical Techniques ◽  
High Strength ◽  
Low Alloy Steel ◽  
Transfer Resistance ◽  
Content Type ◽  
X Ray

Purpose This paper aims to search the optimum content of Ni on the microstructure, phase and electrochemical behavior of high-strength low alloy (HSLA) steel in the 3.5 wt.% NaCl solution. Design/methodology/approach The microstructure and corrosion resistance of Ni-containing HSLA steel in the simulated marine environment was studied by optical microscopy, scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Findings The sample containing 3.55 wt.% of nickel exhibited a finer grain size of 10 μm and a lower icorr of 2.169 µA cm−2. The XRD patterns showed that the Fe-Cr-Ni solid solution, FeC and Cr3C2 were observed in samples when Ni was added. Besides, the 3.55 wt.% of nickel addition enhanced the charge transfer resistance of the low alloy steel which suggested the sample possessed excellent inhibition of electrochemical reaction and corrosion resistance. The XPS spectrum suggested that nickel was beneficial to improve the corrosion resistance of steel by forming protective oxides, and the ratio of Fe2+/Fe3+ in protective oxides was increased. Practical implications Finding the comprehensive performance of HSLA steel which can be applied to unmanned surface vehicles in marine operations. Originality/value This study has a guiding significance for optimizing the composition of HSLA steel in a Cl- containing environment.

scholarly journals On the Influence of Composition and Structure of Carbon-Supported Pt-SnO2 Hetero-Clusters onto Their Electrocatalytic Activity and Durability in PEMFC

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 803 ◽  
Author(s):  
Spasov ◽  
Ivanova ◽  
Pushkarev ◽  
Pushkareva ◽  
Presnyakova ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Photoelectron Spectroscopy ◽  
Layer Structure ◽  
Polymer Electrolyte Membrane ◽  
Carbon Support ◽  
Reduction Reaction ◽  
Support Surface ◽  
Catalytic Layer ◽  
X Ray ◽  
Electrolyte Membrane

A detailed study of the structure, morphology and electrochemical properties of Pt/C and Pt/x-SnO2/C catalysts synthesized using a polyol method has been provided. A series of catalysts supported on the SnO2-modified carbon was synthesized and studied by various methods including transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical methods, and fuel cell testing. The SnO2 content varies from 5 to 40 wt %. The TEM images, XRD and XPS analysis suggested the Pt-SnO2 hetero-clusters formation. The SnO2 content of ca. 10% ensures an optimal catalytic layer structure and morphology providing uniform distribution of Pt-SnO2 clusters over the carbon support surface. Pt/10wt %-SnO2/C catalyst demonstrates increased activity and durability toward the oxygen reduction reaction (ORR) in course of accelerated stress testing due to the high stability of SnO2 and its interaction with Pt. The polymer electrolyte membrane fuel cell current–voltage performance of the Pt/10wt %-SnO2/C is comparable with those of Pt/C, however, higher durability is expected.

The first X-ray photoelectron spectroscopy surface analysis of 4-methyl-2-phenyl-imidazole adsorbed on copper

2015 ◽  
Vol 7 (16) ◽  
pp. 6496-6503 ◽  
Author(s):  
Matjaž Finšgar
Keyword(s):  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Chloride Solution ◽  
Copper Corrosion ◽  
X Ray

4-Methyl-2-phenyl-imidazole is a new compound that can effectively inhibit copper corrosion in chloride solution.

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.

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