scholarly journals Corrosion Activity of Carbon Steel B450C and Low Chromium Ferritic Stainless Steel 430 in Chloride-Containing Cement Extract Solution

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 150
Author(s):  
Lucien Veleva ◽  
David Bonfil ◽  
Ángel Bacelis ◽  
Sebastian Feliu ◽  
Marina Cabrini ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Polarization Resistance ◽  
Passive Films ◽  
Xps Analysis ◽  
Corrosion Activity ◽  
Electrical Circuits ◽  
Extract Solution ◽  
Potentiodynamic Polarization Curves ◽  
Initial Ph ◽  
The Stability

The carbon steel B450C and low chromium SS 430 ferritic samples were exposed for 30 days to chloride-containing (5 g L−1 NaCL) cement extract solution. The initial pH ≈ 13.88 decreased to pH ≈ 9.6, associated mainly with the consumption of OH− ions and the formation of γ-FeOOH, α-FeOOH, Fe3O4 and Cr(OH)3, as suggested by XRD and XPS analysis, in the presence of CaCO3 and NaCl crystals. The deep corrosion damages on B450C were observed around particles of Cu and S as local cathodes, while the first pitting events on the SS 430 surface appeared after 30 days of exposure. The change in the activity of each type of steel was provided by the potentiodynamic polarization curves (PDP). Two equivalent electrical circuits (EC) were proposed for quantitative analysis of EIS (Nyquist and Bode diagrams). The calculated polarization resistance (Rp), as an indicator of the stability of passive films, indicated that SS 430 presented relatively constant values, being two-three orders of magnitude higher than those of the carbon steel B450C. The calculated thickness (d) of the SS 430 passive layers was ≈0.5 nm and, in contrast, that of the B450C passive layers tends to disappear after 30 days.

The Corrosion of Carbon Steel and Stainless Steel in Simulated Geothermal Media

1985 ◽  
Vol 38 (8) ◽  
pp. 1133 ◽  
Author(s):  
BG Pound ◽  
MH Abdurrahman ◽  
MP Glucina ◽  
GA Wright ◽  
RM Sharp
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Stainless Steels ◽  
Polarization Resistance ◽  
Iron Sulfide ◽  
Low Carbon Steel ◽  
Passive Films ◽  
Low Carbon ◽  
Corrosion Rates ◽  
Good Agreement

The corrosion rates of low-carbon steel, and 304, 316 and 410/420 stainless steels in simulated geothermal media containing hydrogen sulfide have been measured by means of the polarization resistance technique. Good agreement was found between weight-loss and polarization resistance measurements of the corrosion rate for all the metals tested. Carbon steel formed a non-adherent film of mackinawite (Fe1 + xS). The lack of protection afforded to the steel by the film resulted in an approximately constant corrosion rate. The stainless steels also exhibited corrosion rates that were independent of time. However, the 410 and 420 alloys formed an adherent film consisting mainly of troilite ( FeS ) which provided only limited passivity. In contrast, the 304 and 316 alloys appeared to be essentially protected by a passive film which did not seem to involve an iron sulfide phase. However, all the stainless steels, particularly the 410 and 420 alloys, showed pitting, which indicated that some breakdown of the passive films occurred.

scholarly journals Phase Transformation of Cr(VI)-Adsorbed Ferrihydrite at Different pH in The Presence of Mn(II): Fate of Mn(II) and Cr(VI)

2021 ◽  
Author(s):  
Zecong Ding ◽  
Fenglian Fu ◽  
Guangzhao Sun ◽  
Chujia Ye
Keyword(s):  
Phase Transformation ◽  
Heavy Metal Ions ◽  
Solid Phase ◽  
Transformation Products ◽  
Transformation Process ◽  
Toxic Heavy Metal ◽  
Chromium Vi ◽  
Initial Ph ◽  
The Stability ◽  
Mn Concentration

Abstract Ferrihydrite is an important sink for the toxic heavy metal ions, such as chromium(VI). As ferrihydrite is thermodynamically unstable and gradually transforms into hematite and goethite, the stability of Cr(VI)-adsorbed ferrihydrite is environmentally significant. This study investigated the phase transformation of Cr(VI)-adsorbed ferrihydrite at different pH in the presence of aqueous Mn(II), as well as the fate of Mn(II) and Cr(VI) in the transformation process of ferrihydrite. Among the ferrihydrite transformation products, hematite was dominant, and goethite was minor. The pre-adsorbed Cr(VI) inhibited the conversion of ferrihydrite to goethite at initial pH 3.0, whereas little amount of adsorbed Mn(II) favored the formation of goethite at initial pH 7.0. After the aging process, Cr species in solid phase existed primarily as Cr(III) in the presence of Mn(II) at initial pH 7.0 and 11.0. The aqueous Mn concentration was predominantly unchanged at initial pH 3.0, whereas the aqueous Mn(II) was adsorbed onto ferrihydrite or form Mn(OH)2 precipitates at initial pH 7.0 and 11.0, promoting the immobilization of Cr(VI). Moreover, the oxidation of Mn(II) occurred at initial pH 7.0 and 11.0, forming Mn(III/IV) (hydr)oxides.

The corrosion inhibition of carbon steel in 5 per cent HCl by Momordica charantia extract

2014 ◽  
Vol 61 (4) ◽  
pp. 255-260 ◽  
Author(s):  
Xie Xuejun* ◽  
Xiao Peng* ◽  
He Jie ◽  
Xiao Wen ◽  
Fu Qiang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Mixed Type ◽  
Inhibition Efficiency ◽  
Xps Analysis ◽  
Content Type ◽  
Isotherm Equation ◽  
Inhibition Effect ◽  
Langmuir Isotherm Equation ◽  
Ir Analysis ◽  
Mixed Type Inhibitor

Purpose – To study the inhibition effect and mechanism of the Momordica charantia extract (BM) to 20 A carbon steel in 5 per cent HCl. Design/methodology/approach – The weight loss, polarization curve, infrared spectrum (IR) analysis and X-ray photoelectron spectrum (XPS) analysis were carefully investigated to indicate the inhibition effect and mechanism of the BM to 20 A carbon steel in 5 per cent HCl. Findings – BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. The inhibition efficiency increased with the increasing concentration of BM. BM behaved as a mixed-type inhibitor, and the inhibition of BM to 20 A carbon steel might be its adsorption through the coordinate covalent bonding among the lone pair electrons of N and O and the empty 3d orbits of Fe, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation. Research limitations/implications – The inhibition of the BM to 20 A carbon steel in 5 per cent HCl. Practical implications – BM could be used in 5 per cent HCl to prevent 20 A carbon steel from corrosion. Social implications – BM could be used in the chemical cleaning of the boilers to prevent the thermal equipments from corrosion. Originality/value – The inhibition effect and mechanism of the BM to 20 A carbon steel were studied by the weight loss, polarization curve, IR analysis and XPS analysis. BM was composed of C, N and O. Functional groups such as N–H and C=O were found in BM. BM behaved as a mixed-type inhibitor. The inhibition efficiency increased with the increasing concentration of BM, and the adsorption on the surface of 20 A carbon steel obeyed the Langmuir isotherm equation.

Photochemical modification of polytetrafluoroethylene into oleophilic property using an ArF excimer laser

1992 ◽  
Vol 7 (7) ◽  
pp. 1912-1916 ◽  
Author(s):  
M. Okoshi ◽  
M. Murahara ◽  
K. Toyoda
Keyword(s):  
Excimer Laser ◽  
Polymer Surface ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Photochemical Reactions ◽  
Xps Analysis ◽  
Spectrum Measurement ◽  
Arf Excimer Laser ◽  
The Stability ◽  
Photochemical Modification

Photochemical modification of the polytetrafluoroethylene (PTFE) with incorporation of the CH3 radical released from the B(CH3)3 molecule excited by an ArF excimer laser has been demonstrated. The incorporation of CH3 radicals and the depletion of fluorine atoms of the polymer surface were studied by XPS analysis and infrared ATR spectrum measurement. In these photochemical reactions, the photoirradiated surface changed into oleophilic. The properties were studied by contact angle measurement. The stability of the oleophilic surface was examined at the elevated temperature of 200 °C for 6 h in O2 or N2 ambient and also by immersing in alkaline or acid water solutions.

scholarly journals Corrosion of carbon steel under CO2 conditions: Effect of CaCO3 precipitation on the stability of the FeCO3 protective layer

2020 ◽  
Vol 162 ◽  
pp. 108214 ◽  
Author(s):  
Riccardo Rizzo ◽  
Shivangi Gupta ◽  
Magdalena Rogowska ◽  
Rajan Ambat
Keyword(s):  
Carbon Steel ◽  
Protective Layer ◽  
The Stability
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