Effect of Molybdate on the Passivation of Carbon Steel in Alkaline Solutions under Open-Circuit Conditions

2016 ◽  
Vol 163 (10) ◽  
pp. C649-C658 ◽  
Author(s):  
Yong Teck Tan ◽  
Sudesh L. Wijesinghe ◽  
Daniel J. Blackwood
Keyword(s):  
Carbon Steel ◽  
Open Circuit ◽  
Alkaline Solutions

Experimental study of the mechanical and corrosion properties of ethyl silicate resin applied on low carbon steel

2021 ◽  
Vol 2 (108) ◽  
pp. 68-74
Author(s):  
M. Ali ◽  
J.H. Mohmmed ◽  
A.A. Zainulabdeen
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Open Circuit Potential ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Treatment Temperature ◽  
Ethyl Silicate ◽  
Low Carbon ◽  
Corrosion Properties ◽  
Mixture Ratio

Purpose: This work aimed at evaluating the properties of the ethyl silicate-based coating that can be applied on low carbon steel. Design/methodology/approach: Two mixture ratio types (2:1, and 3:2) of resin and hardener respectively were used to prepared two specimen models (A and B). Findings: It found that some mechanical properties (tensile, hardness, and impact strength) of ethyl silicate resin were evaluated according to standard criteria. Research limitations/implications: The effect of heat treatments at various temperatures (100, 150, and 200°C) and holding at different times (10, 20 & 30) min on hardness was investigated. Practical implications: Moreover, an open circuit potential corrosion test with a solution of 3.5% Sodium Chloride at room temperature and 60°C was used to determine the corrosion resistance of low carbon steel specimens coated with the two mixture types. Originality/value: The effects of mixture ratios (for resin and hardener) and heat treatment conditions on properties of ethyl silicate-based coating were studied. From obtained results, acceptable values of tensile, hardness, and toughness were recorded. Increasing heat treatment temperature and holding time leads to enhance hardness for both model types. An open circuit potential (OCP) tests show that there is an enhancement of protective properties of ethyl silicate coatings with mixture type B in comparison with type A was achieved. Generally, the results indicate that specimen model B has higher properties as compared with specimen model A.

scholarly journals The Formation of Sulfide Scales on Carbon Steel in Saturated H2S

2020 ◽  
Author(s):  
Noora Alqahtani ◽  
Jiahui Qi ◽  
Aboubakr M. Abdullah ◽  
Nicholas J. Laycock ◽  
Mary P. Ryan
Keyword(s):  
Carbon Steel ◽  
Corrosion Product ◽  
Film Formation ◽  
Open Circuit ◽  
Iron Surface ◽  
Ion Concentration ◽  
Bulk Solution ◽  
Formation Mechanisms ◽  
Structure Thickness ◽  
Circuit Technique

There are three contributing elements of corrosion of Carbon Steel in H₂ S environment: the effect of H2S on water chemistry; electrochemical reactions of the bare iron surface (both anodic and cathodic processes); and the formation and growth of corrosion product layers. The electrochemical reaction commonly contains three stages: first, the reactant transported from the solution (bulk) to the metal surface; then the transfer of the charge reaction on the surface, followed by the reaction product transported away from the iron surface to the bulk solution or the formation and development of the corrosion product which then can decrease the corrosion rate. Development of a robust corrosion model to predict the corrosion process in H2S requires a mechanistic understanding of all these elements. An experimental study was carried out to assess the corrosion of C-steel under open-circuit technique conditions and in solutions at several ranges of time and temperatures. The effect of film composition, morphology, structure, thickness, and ion- concentration of corrosion product films formed on pipeline Carbon Steel in an acid sour solution were examined. The electrochemical behavior of the filmed steel was measured, and the film properties assessed using a range of advanced techniques including Scanning Electron Microscopy (SEM), and Raman spectroscopy (RS). The data will be discussed in terms of film formation mechanisms.

scholarly journals In-Situ Monitoring and Analysis of the Pitting Corrosion of Carbon Steel by Acoustic Emission

2019 ◽  
Vol 9 (4) ◽  
pp. 706 ◽  
Author(s):  
Junlei Tang ◽  
Junyang Li ◽  
Hu Wang ◽  
Yingying Wang ◽  
Geng Chen
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Pitting Corrosion ◽  
Optical Microscope ◽  
Open Circuit ◽  
In Situ Monitoring ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Corrosion Morphology

The acoustic emission (AE) technique was applied to monitor the pitting corrosion of carbon steel in NaHCO3 + NaCl solutions. The open circuit potential (OCP) measurement and corrosion morphology in-situ capturing using an optical microscope were conducted during AE monitoring. The corrosion micromorphology was characterized with a scanning electron microscope (SEM). The propagation behavior and AE features of natural pitting on carbon steel were investigated. After completion of the signal processing, including pre-treatment, shape preserving interpolation, and denoising, for raw AE waveforms, three types of AE signals were classified in the correlation diagrams of the new waveform parameters. Finally, a 2D pattern recognition method was established to calculate the similarity of different continuous AE graphics, which is quite effective to distinguish the localized corrosion from uniform corrosion.

Inhibition Effect of Sodium Nitrite and Silicate on Carbon Steel Corrosion in Chloride-Contaminated Alkaline Solutions

CORROSION ◽  
2011 ◽  
Vol 67 (12) ◽  
pp. 125001-1-125001-12 ◽  
Author(s):  
O. Girčienė ◽  
R. Ramanauskas ◽  
L. Gudavičiūtė ◽  
A. Martušienė
Keyword(s):  
Carbon Steel ◽  
Sodium Nitrite ◽  
Steel Corrosion ◽  
Alkaline Solutions ◽  
Inhibition Effect ◽  
Chloride Contaminated

Effect of Thiosulfate on the SCC Behavior of Carbon Steel Welds Exposed to Concrete Pore Water Under Anoxic Conditions

MRS Advances ◽  
2018 ◽  
Vol 3 (19) ◽  
pp. 1019-1029 ◽  
Author(s):  
B. Kursten ◽  
S. Caes ◽  
R. Gaggiano
Keyword(s):  
Carbon Steel ◽  
Strain Rate ◽  
Pore Water ◽  
Water Solution ◽  
Weld Zone ◽  
Constant Strain Rate ◽  
Open Circuit ◽  
Spent Fuel ◽  
Anoxic Conditions ◽  
High Level

ABSTRACTThe Supercontainer (SC) is the reference concept for the post-conditioning of vitrified high-level nuclear waste and spent fuel in Belgium. It comprises a prefabricated concrete buffer that completely surrounds a carbon steel overpack. Welding is being considered as a final closure technique of the carbon steel overpack in order to ensure its water tightness. Welding is known to induce residual stresses near the weld zone, which may lead to an increased susceptibility to stress corrosion cracking (SCC). In this study, slow strain rate tests were conducted to study the SCC behavior of plain and welded P355 QL2 grade carbon steel exposed to an artificial concrete pore water solution that is representative of the SC concrete buffer environment. The tests were performed at 140°C, a constant strain rate of 5 × 10-7s-1and at open circuit potential under anoxic conditions. The effect of thiosulfate on the SCC behavior was investigated up to levels of 600 mg/L S2O32-.

scholarly journals The Passivation Behavior of Carbon Steel Rods of Nepal in Different Media

1970 ◽  
Vol 22 ◽  
pp. 34-40
Author(s):  
J. Bhattarai ◽  
A. Kafle ◽  
N. P. Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Open Circuit ◽  
Electrochemical Measurements ◽  
High Corrosion Resistance ◽  
Iron Wire ◽  
High Corrosion ◽  
Naoh Solution ◽  
Hcl Solution

The passivation behavior of carbon steel rods of Nepal is studied in 1 M HCl, 0.5 M NaCl and 1 M NaOH solutions at 25°C, open to air using corrosion tests and electrochemical measurements. The corrosion rate of all the examined steel rods is significantly lower in 1 M NaOH solution (about 10-3 mm/y) than those in 0.5 M NaCl (about 10-2 mm/y) and 1 M HCl (about 101-102 mm/y) solutions. The corrosion rate of SR71 steel rod is remarkably lower (3.65 mm/y) than those of other four different steel rods (3-4 x 102 mm/y) of Nepal in 1 M HCl solution. The ennoblement of the open circuit potentials of all the examined steel rod specimens is clearly observed in 1 M NaOH solution than those in 0.5 M NaCl and 1 M HCl solutions. The open circuit potentials of the steel rods are in the passive potential regions of the iron wire in 1 M NaOH solution. Therefore, steel rods of different companies of Nepal showed significantly high corrosion resistance in 1 M NaOH solution at 25°C.DOI: 10.3126/jncs.v22i0.520Journal of Nepal Chemical SocietyVol. 22, 2007 pp.34-40

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