scholarly journals Influence of the Alkaline Reserve of Chloride-Contaminated Mortars on the 6-Year Corrosion Behavior of Corrugated UNS S32304 and S32001 Stainless Steels

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 686 ◽  
Author(s):  
Asunción Bautista ◽  
Francisco Velasco ◽  
Manuel Torres-Carrasco
Keyword(s):  
Corrosion Behavior ◽  
Stainless Steels ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Duplex Microstructure ◽  
Testing Period ◽  
Alkaline Reserve ◽  
Eis Measurements ◽  
High Chloride ◽  
Chloride Concentrations

The durability of two lean corrugated duplex stainless steel (UNS S32304 and S32001) bars manufactured for concrete reinforcement was studied in four different corrosive conditions. These duplex stainless steels are more economical than the most traditional, well-known duplex grade steels (UNS S32205). The research was carried out in mortar samples for six years. In half of the samples, the alkaline reserve had been previously decreased, and their pH was slightly below 12, while in the other half, the pH close to the bars remained as-manufactured. Moreover, there were samples with modified and non-modified alkaline reserve where chlorides had been previously added to the mortar which were exposed to high relative humidity. In other samples—which were partially immersed in 3.5% NaCl—the chlorides entered through the mortar by natural diffusion. The electrochemical behavior of the reinforcements in these conditions was periodically monitored through corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) measurements during the whole testing period. The samples were anodically polarized at the end of the exposure. The results prove that the decrease in the alkaline reserve of the mortars can affect the corrosion behavior of the studied lean duplex in environments with high chloride concentrations. The duplex microstructure of the reinforcements makes it so that the corrosion proceeds by selective attack of the phases.

Electrochemical corrosion study of Pb-free solders

2006 ◽  
Vol 21 (1) ◽  
pp. 62-70 ◽  
Author(s):  
B.Y. Wu ◽  
Y.C. Chan ◽  
M.O. Alam ◽  
W. Jillek
Keyword(s):  
Acid Solution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Linear Polarization Resistance ◽  
Eis Measurements

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.

Studies on Corrosion Behavior of S-165 and HP Supermartensitic Stainless Steels in Cl- Environment

2011 ◽  
Vol 695 ◽  
pp. 425-428
Author(s):  
Duo Wang ◽  
De Ning Zou ◽  
Chang Bin Tang ◽  
Kun Wu ◽  
Huan Liu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Polarization Curves ◽  
Chemical Compositions ◽  
Pitting Potential ◽  
Potentiodynamic Polarization Curves

Supermartensitic stainless steel grades are widely used in oil and gas industries to substitute duplex and super duplex stainless steels these years. In this paper the corrosion behavior of supermartensitic stainless steels with different chemical compositions, S-165 and HP, was investigated in Cl-environment. All the samples were treated by quenching at 1000 °C followed by tempering at 630 °C for 2h. After heat treatment, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) were determined on both kinds of samples. Polarization curves shows that the metastable pitting nucleuses were formed in passive area and the Cr content is the most important factor leading to the differences of pitting potential. The potentiodynamic polarization curves were conducted at various NaCl contents (5000, 15000 and 35000 ppm) and emphasized the need to account for the Cl-sensitivity of samples under corrosion environment. The results show that, the pitting potential decrease with the increase of chloride contents. The behavior of passive film was analyzed by electrochemical impedance spectroscopy.

scholarly journals Variation of Corrosion Potential and Corrosion Behavior of Stainless Steels in Some Underground Corrosion Test Conditions

1989 ◽  
Vol 38 (6) ◽  
pp. 327-332
Author(s):  
Mineo Kobayashi ◽  
Shigeru Kiya ◽  
Rikio Nemoto ◽  
Katsuhiko Horioka ◽  
Satoru Kaneko ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Stainless Steels ◽  
Corrosion Test ◽  
Corrosion Potential ◽  
Test Conditions ◽  
Underground Corrosion

scholarly journals Comparison of the corrosion behavior and surface morphology of NiTi alloy and stainless steels in sodium chloride solution

2016 ◽  
Vol 52 (1) ◽  
pp. 53-61 ◽  
Author(s):  
S. Kozuh ◽  
L. Vrsalovic ◽  
M. Gojic ◽  
S. Gudic ◽  
B. Kosec
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
Electrochemical Impedance ◽  
Layer Structure ◽  
Niti Alloy ◽  
Surface Film ◽  
Open Circuit ◽  
Aisi 316L

The corrosion behavior of NiTi alloy and stainless steels (AISI 316L and X2CrNiMoN22-5-3) in 0.9% sodium chloride (0.154 moll-1) solution was investigated using open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Microstructural analyses before and after electrochemical tests were performed with the scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS). The lowest corrosion current density has NiTi alloy and the extent of the passive range increased in the order AISI 316L stainless steel < NiTi alloy < X2CrNiMoN22-5-3 duplex stainless steel. The oxide film formed on all samples has a double-layer structure consisting of a barrier-type inner layer and a porous outer layer. Oxide films formed on the surface of steels mainly contains iron oxides and chromium oxide, while the surface film of the NiTi alloy mainly contains TiO2 oxide.

The Corrosion Behavior of 9Cr Ferritic–Martensitic Heat-Resistant Steel in Water and Chloride Environment

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Z. Zhang ◽  
P. M. Singh ◽  
Z. F. Hu
Keyword(s):  
Grain Boundaries ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Optical Microscope ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Heat Resistant ◽  
Chloride Environment ◽  
Chloride Concentrations

The corrosion behavior of 9Cr ferritic–martensitic heat-resistant steel was investigated in water and chloride environment at room temperature (RT). The results of linear polarization, electrochemical impedance spectroscopy (EIS), and potentiodynamics (PD) polarization tests on long-term exposure show that 9Cr ferritic–martensitic steel has weaker corrosion resistance and greater pitting corrosion tendency in higher chloride concentrations. Corresponding scanning electron microscopy (SEM) observation displays that higher concentration chloride promotes the pitting initiation. During long-term exposure, pitting susceptibility decreases, the average pit size increases, and the density declines in higher chloride concentrations. Pits in the grains and along the grain boundaries are observed by optical microscope (OM), and it indicates that inclusions in grains and carbide particles at grain boundaries are the sites susceptible to pitting initiation.

Study on the Corrosion Behavior of Two Kinds of Tubing at Different Temperatures

2011 ◽  
Vol 314-316 ◽  
pp. 1335-1341
Author(s):  
Xue Hui Zhao ◽  
Yan Han ◽  
Fa Gen Li ◽  
Zhen Quan Bai ◽  
Bin Wei
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Xrd Analysis ◽  
Tafel Polarization ◽  
Corrosion Rates ◽  
Two Samples ◽  
Different Temperatures

Aimed at the problem of sulfur-resistant corrosion in environment with carbon dioxide(CO2)and trace amounts of hydrogen sulfide (H2S), Tafel polarization curves and electrochemical impedance spectroscopy techniques were employed to study the electrochemistry corrosion behavior of two kinds of 80S(A and B) at different temperatures. The methods of weight-loss，scanning electron microscope and X-ray diffraction (XRD) analysis were used to study on the corrosion behavior of the sulfur-resistant tubes, including electrochemical impedance spectroscopy , average corrosion rates and the corrosion morphologies. The results showed that the corrosion potential and corrosion rates (CR) of two samples were different with the changing of the test temperatures. With the increase of the temperature, the corrosion potential decreased, and the corrosion rates increased, but decreased at 120°C. The corrosion-resistant of A80S was slightly superior to the B80S. The serious pitting corrosion and the maximum average CR occurred at 90°C. The XRD analysis suggested that the main corrosion products were FeS.

Evaluation of Corrosion Behavior of Different Grades of Cast Iron Insodium Chloride Solutions

2020 ◽  
Vol 835 ◽  
pp. 223-228
Author(s):  
Adel Nofal ◽  
Amal S.I. Ahmed ◽  
Wafaa A. Ghanem ◽  
W.A. Hussein ◽  
Nanis K. Mohamed
Keyword(s):  
Cast Iron ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Ductile Cast Iron ◽  
X Ray ◽  
Grey Cast ◽  
Nickel Addition ◽  
Eis Measurements ◽  
Circuit Technique

In this work, the corrosion behavior of different grades of cast iron in 3.5% and 5% of NaClsolution was evaluated. The samples used in this work are; Grey cast iron (GI), ductile cast iron(DI), austempered ductile cast iron (ADI), intercritically austempered cast iron (IADI) and Ni-Resist cast iron. The study was carried out using the Open- Circuit technique (OPC),Potentiodynamic polarization (PP), and electrochemical impedance spectroscopy (EIS)measurements and complemented by Scanning electron microscopy (SEM) and Energydispersive X-ray analysis (EDAX). The results obtained showed that the austempering heattreatment and nickel addition improves the corrosion resistance of cast iron. The order ofcorrosion resistance in NaCl solution is as follows: Ni-Resist > ADI > IADI > DI > GI.

Pitting Corrosion Behavior of Sintered SUS444 Stainless Steel in MgCl2 Solution

2007 ◽  
Vol 539-543 ◽  
pp. 3255-3260 ◽  
Author(s):  
Satoshi Sunada ◽  
Yusuke Miyazaki ◽  
Kazuhiko Majima
Keyword(s):  
Aqueous Solution ◽  
Stainless Steel ◽  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Stainless Steels ◽  
Corrosion Potential ◽  
Corrosion Morphology ◽  
Sem Observation ◽  
Porosity Ratio

The pitting corrosion behavior of sintered SUS 444 stainless steels (P/M specimens) with different kinds of porosity ratios of 13.3, 9.11 and 6.88 % was studied in an aqueous solution containing MgCl2 compared with a conventionally processed SUS 444 stainless steel(I/M specimen). The pitting corrosion potential decreased almost linearly as porosity ratio increased, and the I/M specimen showed the best resistance against the initiation of pitting corrosion. The pitting corrosion morphology by SEM observation showed that more small pits were observed on the specimen with larger porosity ratio while less number but larger diameter pits were observed on the specimen with smaller porosity ratio, and it was also confirmed that the I/M specimen had the least number but the largest and deepest pits.

scholarly journals Corrosion Behavior of Fe40Al Alloy with Additions of Ti, Ag, and Cr in Molten KCl +ZnCl2

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
R. Ademar ◽  
J. G. Gonzalez-Rodriguez ◽  
J. Uruchurtu ◽  
J. Porcayo-Calderon ◽  
V. M. Salinas-Bravo ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Intermetallic Alloy ◽  
Corrosion Performance ◽  
Linear Polarization Resistance ◽  
Potentiodynamic Polarization Curves ◽  
Eis Measurements ◽  
The Stability

The effect of 2.5 at.% Cr, Ti, and Ag on the corrosion behavior of Fe40Al intermetallic alloy in KCl-ZnCl2(1 : 1 M) at 670°C has been evaluated by using electrochemical techniques. Techniques included potentiodynamic polarization curves, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. Results have shown that additions of both Cr and Ti were beneficial to the alloy, since they decreased its corrosion rate, whereas additions of Ag was detrimental, since its additions increased the corrosion rate, although the alloy was passivated by adding Ag or Cr. The best corrosion performance was obtained with the addition of Cr, whereas the highest corrosion rate was obtained by adding Ag. This is explained in terms of the stability of the corrosion products formed film.

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