Study of Corrosion Behavior of Polyuretane/nanoHidroxiapatite Hybrid Coating in Hank Solution at 25 °C

2015 ◽  
Vol 1766 ◽  
pp. 159-165
Author(s):  
G. Carbajal-De La Torre ◽  
A.B. Martinez-Valencia ◽  
A. Sanchez-Castillo ◽  
M. Villagomez-Galindo ◽  
M.A. Espinosa-Medina
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Ionic Species ◽  
Product Layer ◽  
Hybrid Coating ◽  
Corrosion Product Layer ◽  
Ultrasonic Assisted ◽  
Hank Solution ◽  
Corrosion Mechanisms ◽  
Co Precipitation

ABSTRACTThe study of corrosion behavior of polyurethane/nanohydroxyapatite hybrid coating in aerated Hank solution at 25 °C by Potentiodinamic and Electrochemical Impedance techniques was realized. The nanohydroxyapatite (nHA) powders were synthesized by ultrasonic assisted co-precipitation wet chemical method and then mixed with pure polyurethane (PU) during the polymerization. Results were supported by SEM morphologic characterization. Results showed that good corrosion resistance of hybrid coating, showing small corrosion product layer formation. Corrosion mechanisms are affected by an increasing of polarization resistance, promoting decreasing in the corrosion rates. Diffusion of ionic species was the governing mechanism in the corrosion behavior of polyurethane/nanohydroxyapatite hybrid coating.

scholarly journals Atmospheric Corrosion Behavior of 2A12 Aluminum Alloy in a Tropical Marine Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Zhongyu Cui ◽  
Xiaogang Li ◽  
Huan Zhang ◽  
Kui Xiao ◽  
Chaofang Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
Marine Environment ◽  
Atmospheric Corrosion ◽  
Product Layer ◽  
Barrier Effect ◽  
Corrosion Morphology ◽  
Corrosion Product Layer ◽  
Morphology Changes

Atmospheric corrosion behavior of 2A12 aluminum alloy exposed to a tropical marine environment for 4 years was investigated. Weight loss of 2A12 alloy in the log-log coordinates can be well fitted with two linear segments, attributing to the evolution of the corrosion products. EIS results indicate that the corrosion product layer formed on the specimens exposed for 12 months or longer presents a good barrier effect. Corrosion morphology changes from pitting corrosion to severe intergranular corrosion with the extension of exposure time, resulting in the reduction of the mechanical properties.

scholarly journals Experimental Apparent Stern–Geary Coefficients for AZ31B Mg Alloy in Physiological Body Fluids for Accurate Corrosion Rate Determination

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 391
Author(s):  
Federico R. García-Galvan ◽  
Santiago Fajardo ◽  
Violeta Barranco ◽  
Sebastián Feliu
Keyword(s):  
Weight Loss ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Product Layer ◽  
Mg Alloy ◽  
Corrosion Rates ◽  
Corrosion Product Layer ◽  
The Relationship ◽  
Phosphate Buffered Saline

The corrosion behavior of AZ31B Mg alloy exposed to Ringer’s, phosphate-buffered saline (PBS), Hank’s, and simulated body fluid (SBF) solutions for 4 days was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, weight loss, and surface characterization. Changes in corrosion rates with immersion time determined by weight loss measurements were compared with EIS data to determine the possibility of obtaining quantitative electrochemical information. In addition, changes in the protective properties of the corrosion product layer calculated from the EIS parameters were evaluated as a function of their surface chemical composition as determined by X-ray photoelectron spectroscopy (XPS) and visual observations of the corroded specimen’s surface. Apparent Stern–Geary coefficients for the AZ31B Mg alloy in each test solution were calculated using the relationship between icorr from weight loss measurements and the EIS data (both Rp and Rt). This provided experimental reference B′ values that may be used as a useful tool in independent investigations to improve the accuracy of corrosion rates of AZ31B Mg alloy in simulated body solutions.

scholarly journals Corrosion Behavior of Reinforcing Steel Undergoing Stray Current and Anodic Polarization

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 261
Author(s):  
Zhipei Chen ◽  
Dessi Koleva
Keyword(s):  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Cathodic Polarization ◽  
Product Layer ◽  
Reinforcing Steel ◽  
Stray Current ◽  
Polarization Effects ◽  
Steel Rebar ◽  
Corrosion Product Layer ◽  
Curing Regimes

Different concrete structures (viaducts, bridges, or tunnels) in the neighborhoods of railways may be subject to the stray current leaking from the rails. In these cases, the reinforcing rebars embedded in concrete act as conductors, “pick up” the stray current, and can corrode. For simulating the stray current-induced corrosion of metals, most researchers just supplied anodic polarization on samples. However, stray current induces both cathodic polarization and anodic polarization. This work experimentally justifies the different effects of stray current and anodic polarization on reinforcing steel embedded in mortar. A comparison between stray current and anodic polarization effects on the corrosion behavior of embedded steel is performed for both fresh (24 hour-cured) and hardened matrix (28 day-cured) in chloride-free (Cl-free) and chloride-containing (Cl-containing) environments. It is found that in all studied conditions, anodic polarization leads to a significantly different electrochemical performance of the steel rebar compared to the stray current. Hence, anodic polarization cannot reflect all the effects of stray current, and therefore, it has limited significance for simulating stray current. It is also clarified that the curing regimes and starting time of the stray current play significant roles in the formation of a corrosion product layer on the steel surface.

scholarly journals Corrosion behavior of HRB400 and HRB400M steel bars in concrete under DC interference

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qingmiao Ding ◽  
Yuning Gao ◽  
Ruiyang Liu ◽  
Yaozhi Li ◽  
Lei Jin ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Direct Current ◽  
Product Layer ◽  
Corrosion Products ◽  
Product Analysis ◽  
Experimental Conditions ◽  
Corrosion Product Layer ◽  
Steel Bars ◽  
Concrete Solution

AbstractThe influence of direct current interference on the corrosion behavior of HRB400 and HRB400M steel bars in simulated concrete solution was studied using methods such as weight loss experiment, electrochemical experiment, surface technology and product analysis. The research results showed that with the increase of DC interference voltage, the corrosion rates of HRB400 and HRB400M steel bars would increase. The corrosion resistance of HRB400M steel bars was better than HRB400 steel bars under the experimental conditions. In addition, direct current interference could cause damage to the corrosion product layer on the surface of HRB400 steel bars and HRB400M steel bars. And the corrosion form and corrosion product types of HRB400 and HRB400M steel bars would be affected by direct current interference. The main corrosion products of HRB400 steel bars included γ-FeOOH and Fe2O3 when it was not interfered by DC. When DC interference was applied, the main corrosion products included Fe3O4 and Fe2O3. The corrosion products on the surface of HRB400M steel bars were mainly Fe3O4 and Fe2O3, and the types of products increased to form Cr2O3 and MnFe2O4.

Corrosion Behavior of Ferritic-Martensitic Steel in H<sub>2</sub>O Containing CO<sub>2</sub> and O<sub>2</sub> at 50°C to 245°C and 8 MPa

CORROSION ◽  
10.5006/3603 ◽  
2020 ◽  
Author(s):  
Reyixiati Repukaiti ◽  
Richard Oleksak ◽  
John Baltrus ◽  
Lucas Teeter ◽  
Margaret Ziomek-Moroz ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Corrosion Rate ◽  
Oxide Layer ◽  
Martensitic Steel ◽  
Product Layer ◽  
Test Duration ◽  
Corrosion Rates ◽  
Corrosion Product Layer ◽  
Aqueous Environments ◽  
Corrosion Mechanisms

In order to understand the corrosion mechanisms of structural materials in low-temperature components of direct supercritical CO&lt;sub&gt;2&lt;/sub&gt; cycles, immersion experiments were performed in the aqueous environments expected at these conditions. A ferritic-martensitic steel [UNS K91560] was selected as the candidate material. Steel specimens were fully submerged in H&lt;sub&gt;2&lt;/sub&gt;O pressurized with 99% CO&lt;sub&gt;2&lt;/sub&gt; and 1% O&lt;sub&gt;2&lt;/sub&gt; to 8 MPa, and heated up to temperature (either 50°C, 100°C, 150°C, or 245°C), with a test duration of 500 hours. Corrosion rates were calculated based on mass loss. SEM, XRD, XPS, and Raman Spectroscopy were used to characterize microstructure, phases, crystallinity, and composition of the corrosion product layer. Experimental results show that specimens exposed at 100°C had the highest corrosion rate, followed by the specimens exposed at 50°C. The specimens exposed at the highest temperature exhibited the lowest corrosion rate. An outer non-continuous non-protective Fe-rich oxide layer and a well-adhered inner oxide layer containing both Fe and Cr formed on the specimen surfaces. The inner oxide layer changed from amorphous to crystalline as temperature increased.

Simulation of The State of Carbon Steel n Years After Disposal with n Years of Corrosion Product on its Surface in a Bentonite Environment

1994 ◽  
Vol 353 ◽  
Author(s):  
Yoichi Kojima ◽  
Toshinobu Hioki ◽  
Shigeo Tsujikawa
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Steel Corrosion ◽  
Product Layer ◽  
The State ◽  
Corrosion Product Layer ◽  
Time Frames

AbstractThe use of bentonite as buffer and carbon steel as overpack material for the geological disposal of nuclear waste is under investigation. To better assess the long term integrity of the carbon steel overpack, a quantitative analysis of the corrosion behavior on the steel surface for time frames beyond that of feasible empirical determination is required. The state n years after disposal, consisting of Carbon Steel / Corrosion Products + Bentonite / Water, was simulated and the corrosion behavior of the carbon steel in this state investigated. The following facts became apparent. Both the corrosion rate and the non-uniformity of it increased with increase in the corrosion product content in the compacted bentonite. When the corrosion product layer was formed between the carbon steel and the bentonite, it ennobled the corrosion potential and increased the corrosion rate.

Micro-Electrochemical Characterization of the Synergism of Hydrogen and Stress in Anodic Dissolution of Steel and Its Implication on Pipeline Stress Corrosion Cracking

2008 ◽  
Author(s):  
Y. Frank Cheng ◽  
X. Tang
Keyword(s):  
Stress Corrosion ◽  
Anodic Dissolution ◽  
Stress Corrosion Cracking ◽  
Electrochemical Impedance ◽  
Product Layer ◽  
Corrosion Cracking ◽  
Stress Effect ◽  
Effect Factor ◽  
Neutral Ph ◽  
Corrosion Product Layer

Localized electrochemical impedance spectroscopy (LEIS) technique was used to investigate the effects of stress and hydrogen as well as their synergism on anodic dissolution of steel under near-neutral pH condition where pipeline stress corrosion cracking (SCC) has been reported. There exists a threshold stress value, under which there is little effect of applied stress on anodic dissolution of steel. Above the value, the dissolution rate of steel increases with the stress. Hydrogen-charging enhances anodic dissolution of steel, which is attributed to the effect of hydrogen on the formation of corrosion product layer and the activation of the steel. The stress effect factor and the stress-hydrogen synergism effect factor are quantified. A detailed analysis shows that the synergism of stress and hydrogen at crack tip is expected to play an important role in near-neutral pH SCC of pipelines.

Effect of Zn Content on Structure, Roughness and Corrosion Behavior of Zn-Ni Alloys

2019 ◽  
Vol 17 (17) ◽  
pp. 17-22
Author(s):  
Hayette Faid
Keyword(s):  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Stripping Voltammetry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloys ◽  
Sulfate Bath ◽  
Zn Content ◽  
Polarization Test ◽  
Δ Phase

AbstractIn this work, Zn-Ni alloys have been deposited on steel from sulfate bath, by electrodeposition method. The effect of Zn content on deposits properties was studied by cyclic voltammetry (CV), chronoaperometry (CA), linear stripping voltammetry (ALSV) and diffraction (XRD) and scanning electronic microscopy (SEM). The corrosion behavior in 3.5 wt. NaCl solution was examined using anodic polarization test and electrochemical impedance spectroscopy. X-ray diffraction of show that Zn-Ni alloys structure is composed of δ phase and γ phase, which increase with the decrease of Zn content in deposits. Results show that deposits obtained from bath less Zn2+ concentration exhibited better corrosion resistance.

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