Corrosion study of low carbon steel under simulated geological disposal environments for HLW in China

2020 ◽  
Author(s):  
Junhua Dong
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Dissolved Oxygen ◽  
Open Circuit Potential ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Localized Corrosion ◽  
Low Carbon ◽  
Simulated Groundwater

<p>In the multi-barrier system of HLW repository, overpack is the first barrier to isolate high-level radioactive nuclides from biosphere, and Low carbon steel has been considered to be a promising candidate material for manufacturing the oberpack due to its good mechanical performance and workability and weldability. However, during thousands of years of geological disposal, the corrosion resistance of low carbon steel and its corrosion evolution behavior are the first element that must be fully understood, because it determines the life cycle of the artificial barrier.</p><p>Conventional studies had suggested that the corrosion of low carbon steel under the deep geological environment was driven by hydrogen evolution reaction (HER) based on that the dissolved oxygen was completely depleted during the long term disposal. However, the residual oxygen content is a critical factor to determine the corrosion mode of cathodic reduction reaction. Thermodynamics data indicated that the initial ferrous corrosion products formed in the deaerated bicarbonate solution can be chemically oxidized into ferric substance by the trace content of dissolved oxygen, and the accumulated FeOOH as a cathodic depolarizer significantly increased the open circuit potential and enhanced the corrosion rate of the low carbon steel. Moreover, chloride and sulfate in the simulated groundwater can reduce the increase of open circuit potential but it still promotes the corrosion of the low carbon steel. As the environments contained aggressive anions and high concentration of dissolved oxygen, low carbon steel was prone to suffer from the localized corrosion and the corrosion rate was obviously increased. By alloying with some contents of Ni and Cu, the corrosion rate of low alloy steel was decreased by an order of magnitude and it was less prone to suffer from the localized corrosion.</p><p>Under the conditions of simulated groundwater with different content of GMZ bentonite，the bentonite colloidal particle layer attached to the surface of low carbon steel showed blocking effect on resisting oxygen diffusion to the steel substrate, which consequently decrease the further oxidation of ferrous to ferric substances and the corrosion rate of low carbon steel. However, the barrier performance of bentonite colloids would be deteriorated due to their coagulation caused by the ferrous ions dissolved from the steel substrate. High content of bentonite was beneficial to maintain and to prolong the stabilization of the barrier system. An equivalent circuit model which correlates with the interfacial structure between electrode substrate and rust and bentonite layer was proposed. The fitting results showed a very good match between the model and experimental data, and the evolution of the results was also in agreement with real changes.</p>

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.

Conducting polyaniline/multi-wall carbon nanotubes composite paints on low carbon steel for corrosion protection: electrochemical investigations

2013 ◽  
Vol 67 (8) ◽  
Author(s):  
Pravin Deshpande ◽  
Sanket Vathare ◽  
Shashikant Vagge ◽  
Elena Tomšík ◽  
Jaroslav Stejskal
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Steel ◽  
Corrosion Protection ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Low Carbon ◽  
Multi Wall Carbon Nanotubes ◽  
Poly Aniline

AbstractThe coaxial coating of multi-wall carbon nanotubes (MWCNT) with poly(aniline) (PANI) was synthesised and a paint was prepared containing conducting PANI-MWCNT composite. The corrosion protection performance was assessed by open circuit potential measurements, potentiodynamic polarisation, and electrochemical impedance spectroscopy. The corrosion rate of low-carbon steel coated with 1.5 mass % of PANI-MWCNT-based paint in 3.5 mass % sodium chloride solution was found to be 0.037 mm y−1, about 5.2 times lower than that of unpainted low-carbon steel and 3.6 times lower than that of epoxy painted steel.

scholarly journals Electrochemical studies of the synergistic combination effect of thymus mastichina and illicium verum essential oil extracts on the corrosion inhibition of low carbon steel in dilute acid solution

2020 ◽  
Vol 11 (1) ◽  
pp. 1-13
Author(s):  
Roland Tolulope Loto ◽  
Samuel Keme Ororo
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Open Circuit Potential ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Low Carbon ◽  
Inhibition Effect ◽  
Illicium Verum ◽  
Hcl Solution

AbstractInhibition effect of the synergistic combination of thymus mastichina and illicium verum oil extracts (TMAV) on the corrosion inhibition of low carbon steel in 0.5 M H2SO4 and HCl solution was studied by weight loss analysis, potentiodynamic polarization, open circuit potential measurement, ATF-FTIR spectroscopy, and optical microscopy and macroscopic characterization. Results from weight loss shows TMAV performed more effectively in H2SO4 solution compared to HCl with optimal inhibition efficiency of 81.24% and 68.33%. Effective inhibition performance was observed at all TMAV concentration in H2SO4 compared to HCl where TMAV performed poorly until 5% concentration. The optimal inhibition performances from potentiodynamic polarization are 80.85% and 70.43%. The corresponding corrosion current density and polarization resistance are 7.16 × 105 A/cm2 and 8.01 × 105 A/cm2, and 331.73 and 284 Ω. TMAV exhibited mixed type inhibition effect in both acid solutions, strongly influencing the anodic-cathodic plot configurations with respect to concentration. Open circuit potential plots without TMAV were significantly electronegative compared to the plots at 1% and 5% TMAV concentration which were relative electropositive due to decreased thermodynamic tendency of the carbon steel to corrode. The corresponding plots at 1% and 5% TMAV concentration from HCl solution were thermodynamically unstable with significant active-passive corrosion behaviour. TMAV inhibited through chemisorption adsorption according to Langmuir and Freudlich adsorption isotherms in H2SO4 solution, and Frumkin and Freundlich adsorption isotherms in HCl solution with correlation coefficient values between 0.7 and 0.9. FTIR spectroscopic analysis exposed the functional groups and atomic bonds responsible for corrosion inhibition.

Sulfurous Acid Corrosion of Low Carbon Steel at Ordinary Temperatures - I. Its Nature

CORROSION ◽  
1966 ◽  
Vol 22 (5) ◽  
pp. 143-146 ◽  
Author(s):  
W. McLEOD ◽  
R. R. ROGERS
Keyword(s):  
Water Vapor ◽  
Carbon Steel ◽  
Sulfur Dioxide ◽  
Corrosion Rate ◽  
Acid Corrosion ◽  
Low Carbon Steel ◽  
Rate Data ◽  
Low Carbon ◽  
Sulfurous Acid ◽  
Ordinary Temperature

Abstract Corrosion rate data are presented for low carbon steel in (1) a combination of sulfur dioxide, water vapor and air, and (2) aqueous solutions of sulfurous acid in the absence of air, at ordinary temperature. Information as to the nature of the corrosion products is presented and it is shown that this depends on the place in which the corrosion takes place to an important extent.

Effects of Dipping Pretreatment on the Flame Deposition of Carbon Nanostructure on the Low Carbon Steel Substrate

2013 ◽  
Vol 734-737 ◽  
pp. 2269-2272
Author(s):  
Hong Mei Zhu ◽  
Shu Mei Lei ◽  
Tong Chun Kuang
Keyword(s):  
Nitric Acid ◽  
Carbon Steel ◽  
Acid Solution ◽  
Carbon Nanofibers ◽  
Carbon Nanoparticles ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Carbon Nanostructure ◽  
Flame Method

In this paper, a low carbon steel was used as the substrate to prepare the carbon nanostructural materials by the oxygen-acetylene flame method. The experimental results show that the composite products including nodular carbon nanoparticles and amorphous carbon were obtained on the substrate after a mechanical polishing pretreatment. Comparatively, the short tubular carbon nanofibers with the diameter of around 100 nm were deposited on the substrate pretreated by dipping in the concentrated nitric acid solution. The possible mechanism for the growth of such carbon nanofibers was discussed.

Corrosion behaviors of iron, chromium, nickel, low-carbon steel and four types of stainless steels in liquid antimony-tin alloy

CORROSION ◽  
10.5006/3820 ◽  
2021 ◽  
Author(s):  
Wei Liu ◽  
Huayi Yin ◽  
Kaifa Du ◽  
Bing Yang ◽  
Dihua Wang
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Stainless Steels ◽  
Liquid Metals ◽  
Low Carbon Steel ◽  
Solid Substrate ◽  
Low Carbon ◽  
Corrosion Resistant ◽  
Corrosion Behaviors ◽  
Iron Chromium

Corrosion-resistant metals and alloys towards liquid metals determine the service performances and lifetime of the devices employing liquid metals. This paper studies the static corrosion behaviors of iron, chromium, nickel, low carbon steel, and four types of stainless steels (SS410, SS430, SS304, SS316L) in liquid Sb-Sn at 500 oC, aiming to screen corrosion-resistant SS for Li||Sb-Sn liquid metal batteries (LMBs). The corrosion rates of Fe and Ni are 0.94 μm h-1 and 6.03 μm h-1 after 160 h’s measurement, respectively. Cr shows a low corrosion rate of < 0.05μm h-1, which is due to the formation of a relatively stable Cr-Sb layer that may be able to prevent the interdiffusion between the solid substrate and liquid Sb-Sn. Ni has a high corrosion rate because the formed Ni-Sb and Ni-Sn compounds are soluble in the liquid Sb-Sn. The corrosion products of both pure metals and SS can be predicted by thermodynamic and phase diagram analysis. Among the four types of SS, SS430 shows the best corrosion resistance towards liquid Sb-Sb with a corrosion rate of 0.19 μm h-1. Therefore, a liquid Sb-Sn resistant material should have a high Cr content and a low Ni content, and this principle is applicable to design metallic materials not only for LMBs but also for other devices employing liquid Sb- and Sn-containing liquid metals.

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 The Microstructure of Annealed Galfan Coating on Steel Substrate

2012 ◽  
Vol 57 (2) ◽  
pp. 517 ◽  
Author(s):  
M. Żelechower ◽  
J. Kliś ◽  
E. Augustyn ◽  
J. Grzonka ◽  
D. Stróż ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Electron Diffraction ◽  
Steel Substrate ◽  
Low Carbon Steel ◽  
Alloy Coating ◽  
Annealed Sample ◽  
Low Carbon ◽  
Interface Area ◽  
Two Phase ◽  
Al Content

The Microstructure of AnnealedGalfanCoating on Steel SubstrateThe commercially availableGalfancoating containing 5-7wt.% of Al deposited on the low carbon steel substrate by hot dipping has been examined with respect to the microstructure of the coating/substrate interface area. The application of several experimental techniques (SEM/EDS, XRD, TEM/AEM/EDS/ED) allowed demonstrating the two-phase structure of the alloy coating in non-treated, commercially availableGalfansamples: Zn-rich pre-eutectoidηphase grains are surrounded by lamellar eutectics ofβ-Al andη-Zn. The transition layer between the alloy coating and steel substrate with the considerably higher Al content (SEM/EDS, TEM/EDS) has been found in both non-treated and annealed samples (600°C/5 minutes). Only the monoclinic FeAl3Znxphase however was revealed in the annealed sample (TEM/electron diffraction) remaining uncertain the presence of the orthorhombic Fe2Al5Znxphase, reported by several authors.

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