scholarly journals Electrochemical and Microstructural Analysis of FeS Films from Acidic Chemical Bath at Varying Temperatures, pH, and Immersion Time

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ladan Khaksar ◽  
Gary Whelan ◽  
John Shirokoff
Keyword(s):  
Corrosion Rate ◽  
Immersion Time ◽  
Iron Sulfide ◽  
Microstructural Analysis ◽  
Corrosion Products ◽  
Initial Increase ◽  
Protective Film ◽  
Experimental Conditions ◽  
X Ray ◽  
Increasing Temperature

The corrosion resistance and corrosion products of 4130 alloy steel have been investigated by depositing thin films of iron sulfide synthesized from an acidic chemical bath. Tests were conducted at varying temperatures (25°C–75°C), pH levels (2–4), and immersion time (24–72 hours). The corrosion behavior was monitored by linear polarization resistance (LPR) method. X-ray Diffraction (XRD), Energy Dispersive X-ray (EDX) spectroscopy, and Scanning Electron Microscopy (SEM) have been applied to characterize the corrosion products. The results show that, along with the formation of an iron sulfide protective film on the alloy surface, increasing temperature, increasing immersion time, and decreasing pH all directly increase the corrosion rate of steel in the tested experimental conditions. It was also concluded that increasing temperature causes an initial increase of the corrosion rate followed by a large decrease due to transformation of the iron sulfide crystalline structure.

Effect of Temperature on H2S/CO2 Corrosion Behaviors of P110-3Cr Steel

2013 ◽  
Vol 816-817 ◽  
pp. 54-59 ◽  
Author(s):  
Xin Su ◽  
Jian Bo Sun ◽  
Chong Sun ◽  
Bin Han
Keyword(s):  
Corrosion Rate ◽  
Corrosion Product ◽  
Iron Sulfide ◽  
Energy Dispersive Spectrometer ◽  
Corrosion Products ◽  
Effect Of Temperature ◽  
General Corrosion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Corrosion Behaviors

Flowing solution environment containing H2S/CO2was simulated by high temperature and high pressure autoclave. Corrosion behaviors of P110-3Cr pipeline steels were investigated by Weight loss, Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Energy dispersive spectrometer (EDS). Effect of temperature on corrosion rate and corrosion product was discussed. The results showed that corrosion rate of P110-3Cr steel decrease at the beginning and then increased with rising temperature. The corrosion types are general corrosion. P110-3Cr has resistance to local corrosion. Mackinawite (FeS0.9) is formed as corrosion product in low-temperature condition. With temperature increasing the corrosion products are dominated by mackinawite (FeS0.9) and Cubic iron sulfide (Fe3S4). When temperature increased to 150 ¡æ, the corrosion products are made up of Hexagonal iron sulfide (Fe0.96S) and Orthorhombic Marcasite (FeS2). No siderite (FeCO3) is detected, the corrosion is controlled by H2S; Cr is rich in the corrosion scale.

scholarly journals Effect of Temperature on the Corrosion Behavior of Biodegradable AZ31B Magnesium Alloy in Ringer’s Physiological Solution

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 591 ◽  
Author(s):  
Sebastian Feliu ◽  
Lucien Veleva ◽  
Federico García-Galvan
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Physiological Solution ◽  
Corrosion Layer ◽  
Effect Of Temperature ◽  
X Ray ◽  
Ringer’S Solution ◽  
Corrosion Behaviors ◽  
Az31b Alloy ◽  
Increasing Temperature

In this work, the corrosion behaviors of the AZ31B alloy in Ringer’s solution at 20 °C and 37 °C were compared over four days to better understand the influence of temperature and immersion time on corrosion rate. The corrosion products on the surfaces of the AZ31B alloys were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) provided information about the protective properties of the corrosion layers. A significant acceleration in corrosion rate with increasing temperature was measured using mass loss and evolved hydrogen methods. This temperature effect was directly related to the changes in chemical composition and thickness of the Al-rich corrosion layer formed on the surface of the AZ31B alloy. At 20 °C, the presence of a thick (micrometer scale) Al-rich corrosion layer on the surface reduced the corrosion rate in Ringer’s solution over time. At 37 °C, the incorporation of additional Mg and Al compounds containing Cl into the Al-rich corrosion layer was observed in the early stages of exposure to Ringer’s solution. At 37 °C, a significant decrease in the thickness of this corrosion layer was noted after four days.

scholarly journals Corrosion Behavior of 3% Cr Casing Steel in CO2-Containing Environment: A Case Study

2018 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Lin Xu ◽  
Jie Xu ◽  
Ming-biao Xu ◽  
Si-yang Li ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Exposure Time ◽  
Corrosion Products ◽  
Localized Corrosion ◽  
Internal Corrosion ◽  
Tafel Polarization ◽  
Water Cut ◽  
Increasing Temperature

Introduction: The production casing of 3% Cr steel has encountered severe internal corrosion in Huizhou Oilfield. To disclose corrosion behavior of inner casing, a series of corrosion exposure tests were systematically conducted on 3% Cr coupons in terms of in-field conditions. Material and Methods: Influence of exposure time, temperature, and water-cut on the CO2 corrosion of 3% Cr steel was investigated, and analyses on weight loss, composition and morphology of corrosion product, and Tafel polarization curves were further carried out. Result: The results showed that the corrosion rate of 3% Cr steel increased with increasing temperature, but such trend descended when the temperature exceeded 65°C due to formation of an compact and adherent corrosion product film on the surface of 3% Cr coupons. While varying exposure time from 7 days to 14 days, the corrosion rate decreased, and the Cr and O enrichment was determined in the corrosion products. The corrosion rate of 3% Cr steel increased with a continuous increment of water-cuts, especially when the water-cut was larger than 40%. Conclusion: The localized corrosion can happen at the lower water-cut due to the presence of amorphous films. The main corrosion products were FeCO3, Cr5O12, Fe2O3, and Fe-Cr. Entry of CO2 to the simulated formation water caused an increase in the anodic Tafel slope, and accelerated dissolution of 3% Cr steel.

scholarly journals Efektivitas Ekstrak Kulit Buah Maja Sebagai Inhibitor pada Baja Karbon Aisi 1020 dalam Medium Korosif Nacl 3% dengan Variasi Waktu Perendaman

2020 ◽  
Vol 8 (2) ◽  
pp. 159-168
Author(s):  
Ismi Nurhayati ◽  
◽  
Pulung Karo Karo ◽  
Syafriadi Syafriadi ◽  
◽  
...  
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosive Medium ◽  
Immersion Time ◽  
Corrosion Products ◽  
Skin Extract ◽  
Fruit Skin ◽  
Steel Aisi

Research has been conducted on the effectiveness of maja fruit skin extract as an inhibitor of carbon steel AISI 1020 in a corrosive medium NaCl 3% with variations in immersion time. The samples carbon steel AISI 1020 were immersed in corrosive medium NaCl 3% without being given and given the inhibitor of maja skin extract with a concentration of 0.8% for 5, 15, 25, 35, and 45 days. Calculation of reduction in corrosion rate is carried out by the method of weight loss. The results showed that the addition of the maja fruit skin extract inhibitor was effective in reducing the corrosion rate of the sample with the greatest efficiency at 35 days immersion, which was equal to 72.35%. The results of XRD characterization show that the phase formed is pure Fe and Fe3O4 phase which is a corrosion product is immersed without inhibitor. The results of SEM characterization showed that the microstructure of the surface of the sample after immersion was there were cracks, holes, and lumps which indicated that the sample had been corroded. The results of EDS characterization show that in the soaked sample there were corrosion products in the form of FeO compounds whose magnitude increased every time immersion.

scholarly journals Effect of Si Content on the Corrosion Behavior of 420 MPa Weathering Steel

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 486 ◽  
Author(s):  
Sun ◽  
Yu ◽  
Zhang ◽  
Yan ◽  
Lu ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Silicon Oxide ◽  
Corrosion Products ◽  
Weathering Steel ◽  
X Ray ◽  
Initial Stage ◽  
Amorphous Compounds ◽  
Si Content

: The effect of Si content (0.12%, 0.34%, and 0.48%) on the corrosion behavior of weathering steel in a simulated marine environment was investigated in a dry/wet alternating cycle corrosion experiment. Corrosion weight gain, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and electrochemical methods were used to measure the regularity and nature of the rust. The results show that the corrosion process could be divided into an initial stage where the corrosion rate increased and a later stage where the corrosion rate decreased before remaining stable. The corrosion rate was the lowest for a Si content in the weathering steel of 0.48%. The corrosion products of all three steel groups contains α-FeOOH, β-FeOOH, γ-FeOOH, Fe3O4, and large amounts of amorphous compounds. Furthermore, Si benefits the transformation of β-FeOOH and γ-FeOOH to stable phases. The addition of the Si alloying element is beneficial to the formation of dense and compact rust layers that enhance the electrochemical resistance of weathering steel and silicon oxide influences the self-corrosion potential of the corrosion products.

The Experiment Research of Corrosion Behavior about Tubing Steel in Environment with High H2S and CO2 Content

2013 ◽  
Vol 318 ◽  
pp. 284-292
Author(s):  
Wen Fei Li ◽  
Xuan Ye Li
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Iron Sulfide ◽  
Corrosion Process ◽  
Corrosion Products ◽  
Second Phase ◽  
Simulated Environments ◽  
Transmission Electron ◽  
Dislocation Pinning ◽  
Actual Yield

The corrosion behavior of C100 steel in simulated environments with high H2S and CO2 content was studied through high-temperature and high-pressure autoclave, and the H2S stress corrosion cracking (SSC) resistance of C100 steel was evaluated by SSC tests. Scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD) technique were employed to characterize the corrosion products and the metal matrix. The results indicate that all of the corrosion products in this investigation are mainly composed of different types of iron sulfide such as Fe0.95S, FeS0.9, Fe0.985S, Fe7S8 and FeS, and the absence of iron carbonate in the corrosion scales suggests that the corrosion process is governed by H2S corrosion. The corrosion rate decreases in the initial stage and then increases with the enhance of the temperature. There exists a minimum corrosion rate at about 110°C. Under the partial pressure of H2S lower than 9MPa, the corrosion rate decreases with the increase of P . While over 9MPa, a higher P will result in a faster corrosion process. When the applied stress is 72 %, 80 % and 85 % of actual yield strength (AYS), all tested specimens show no crack, which reveals a superior SSC resistance. The precipitation of the second phase particles at the grain boundary or in crystal grain, the dislocation tangle and the dislocation pinning of the dispersion carbonide hinder the SSC cracks to propagate.

Corrosion analysis of copper T2 exposed to polluted atmospheres and study on prediction model

2017 ◽  
Vol 35 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Zhiping Zhu ◽  
Xiandi Zuo ◽  
Zhaohui Ying
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Corrosion Products ◽  
Good Prediction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Early Stages ◽  
Metal Materials ◽  
The Mathematical Model

AbstractThe power supply accident caused by the corrosion of metal materials in the substation has become an important issue that affects the safe operation of the power grid. The corrosion of copper T2 was the most serious. The corrosion behaviour of copper T2 in SO2- and H2S-containing atmospheric environments was investigated using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), and X-ray diffraction (XRD), and the nonequidistant grey GM(1,1) model was established of which the precision and forecast dependability were evaluated. Results indicated that the corrosion rate of copper in the SO2 environment increased in the early stages of corrosion and then gradually decreased at the later stages. In contrast, the corrosion rate of copper in the H2S environment slowly increased in the early stages of corrosion and then sharply increased at the later stages. The corrosion products in the SO2 environment consisted of cuprite (Cu2O) and brochantite [Cu4(OH)6SO4], whereas the corrosion products in the H2S environment were Cu2O and chalcocite (Cu2S). The mathematical model has good prediction dependability and higher forecast reliability.

Corrosion behavior of 20# steel in aqueous CO2 solution under stratified gas-liquid two-phase flow condition

2019 ◽  
Vol 66 (1) ◽  
pp. 11-18
Author(s):  
Guirong Yang ◽  
Wenming Song ◽  
Fuqiang Wang ◽  
Ying Ma ◽  
Yuan Hao
Keyword(s):  
Corrosion Rate ◽  
Flow Condition ◽  
Two Phase Flow ◽  
Corrosion Products ◽  
Dense Layer ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
X Ray ◽  
Loose Layer

PurposeThis paper aims to investigate the corrosion rate, surface morphology and composition of corrosion products of 20# seamless steel in aqueous CO2 solution under stratified gas-liquid two-phase flow condition. The development of a corrosion products layer has also been discussed. Design/methodology/approachThe following methods were used: weight loss method, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. FindingsThe corrosion rate curve presents an irregular zigzag change trend with a gradual increase in time. The peak value of the corrosion rate appears when the corrosion time is 4 h and 8 h. The corrosion products layer is composed of two sub-layers: the inner dense layer that is about 6 µm thick and the outer loose layer that is about 9 µm thick when the corrosion time is 8 h. The main corrosion product are FeCO3 and Fe2O3. Originality/valueThe atomic ratio of Fe/C/O is relatively stable for the inner dense layer, but changes in thickness for the outer loose layer. There is a densification stage after a loose corrosion products layer forms, and it is periodic.

scholarly journals Corrosion products and mechanism on NiTi shape memory alloy in physiological environment

2010 ◽  
Vol 25 (2) ◽  
pp. 350-358 ◽  
Author(s):  
Tao Hu ◽  
Chenglin Chu ◽  
Yunchang Xin ◽  
Shuilin Wu ◽  
Kelvin W.K. Yeung ◽  
...  
Keyword(s):  
Shape Memory ◽  
Corrosion Product ◽  
Immersion Time ◽  
Product Layer ◽  
Corrosion Products ◽  
Niti Shape Memory Alloy ◽  
Nickel Concentration ◽  
Corrosion Mechanism ◽  
X Ray ◽  
Corrosion Product Layer

Despite many investigations on the corrosion behavior of NiTi shape memory alloys (SMAs) in various simulated physiological solutions by electrochemical measurements, few have reported detailed information on the corrosion products. In the present study, the structure and composition of the corrosion products on NiTi SMAs immersed in a 0.9% NaCl physiological solution are systematically investigated by scanning electron microscopy (SEM), x-ray energy dispersion spectroscopy (EDS), and x-ray photoelectron spectroscopy (XPS). It is found that attack by Cl−results in nickel being released into the solution and decrease in the local nickel concentration at the pitting sites. The remaining Ti reacts with dissolved oxygen from the solution to form titanium oxides. After long-term immersion, the corrosion product layer expands over the entire surface and XPS reveals that the layer is composed of TiO2, Ti2O3, and TiO with relatively depleted Ni. The growth rate of the corrosion product layer decreases with immersion time, and the corrosion product layer is believed to impede further corrosion and improve the biocompatibility of NiTi alloy in a physiological environment. It is found that the release rate of nickel is related to the surface structure of the corrosion product layer and immersion time. A corrosion mechanism is proposed to explain the observed results.

Corrosion Resistance of X52 Pipeline Steel at Sea Mud Zone

2014 ◽  
Vol 599-601 ◽  
pp. 40-43
Author(s):  
Xia Zhao ◽  
Shuan Liu ◽  
Bao Rong Hou
Keyword(s):  
Corrosion Resistance ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Pipeline Steel ◽  
Corrosion Current ◽  
Corrosion Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tafel Polarization ◽  
Sea Mud

Corrosion resistance of X52 pipeline steel at sea mud zone in Qingdao Huiquan test station was investigated by using Tafel polarization curves and electrochemical impedance spectroscopy (EIS). The morphology and chemical composition of the corrosion products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that the corrosion current density of X52 pipeline steel increased with immersion time. The corrosion products were loose and mainly included Fe3O4, Fe2O3 and FeOCl, which absorbed on the specimen surface accelerating the cathodic depolarization reaction.

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