Influence of Current Density on Coating Mass Distribution and Surface Coverage during Electrodeposition of Tin on Carbon Steel

2020 ◽  
pp. 8119-8128
Author(s):  
Fengjing Wu ◽  
Keyword(s):  
Carbon Steel ◽  
Mass Distribution ◽  
Current Density ◽  
Surface Coverage ◽  
Coating Mass

Comparative Cathodic Behavior of ~9% Cr and Plain Steel Reinforcement in Concrete

CORROSION ◽  
2012 ◽  
Vol 68 (4) ◽  
pp. 045003-1-045003-10 ◽  
Author(s):  
M. Akhoondan ◽  
A.A. Sagüés
Keyword(s):  
Carbon Steel ◽  
Oxygen Reduction ◽  
Current Density ◽  
Surface Condition ◽  
Corrosion Current ◽  
Reduction Reaction ◽  
Cathodic Current Density ◽  
Cathodic Current ◽  
Steel Rebar ◽  
Cathodic Region

The extent of the oxygen reduction reaction in concrete was evaluated for ~9% Cr rebar approaching the ASTM A1035 specification and compared to that of conventional carbon steel rebar, at ages of up to ~1 year. Cathodic strength was measured by the cathodic current density developed at −0.35 V vs. copper/copper sulfate (Cu/CuSO4 [CSE]) and −0.40 VCSE in cyclic cathodic potentiodynamic polarization tests, both in the as-received condition with mill scale and with scale removed by glass bead surface blasting. In both conditions the ~9% Cr alloy was a substantially weaker cathode, by a factor of several fold, than carbon steel. Within each material, the surface-blasted condition yielded also much lower cathodic current density than the as-received condition. For a small anode-large cathode system with a given anode polarization function, and no important oxygen reduction concentration polarization, the corrosion current was projected to be significantly lower if the cathodic region were ~9% Cr instead of plain steel rebar with comparable surface condition. There was strong correlation between the charge storage capability of the interface and the extent of cathodic reaction of oxygen. The result cannot be ascribed solely to differences in effective surface area between the different materials and conditions.

Protective behavior of volatile corrosion inhibitor on atmospheric corrosion process of carbon steel under thin electrolyte liquid film of chloride solutions

2020 ◽  
Vol 10 (9) ◽  
pp. 1435-1443
Author(s):  
Dong Wang ◽  
Chenxi Wang ◽  
Changqing Fang ◽  
Xing Zhou ◽  
Mengyuan Pu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Liquid Film ◽  
Corrosion Inhibitor ◽  
Current Density ◽  
Atmospheric Corrosion ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Corrosion Process ◽  
Closed Container

The corrosion process of carbon steel and corrosion resistance behavior of volatile corrosion inhibitor (VCI) under thin electrolyte liquid film containing chloride was investigated by electrochemical measurements and surface characterization. Results indicated that composite VCI was composed of sodium molybdate and sodium benzoate, and exhibited higher corrosion resistance in 3.5% NaCl solution compared with absence of VCI. The corrosion current density obviously decreased with presence of VCI, and the synergies between binary components increased the corrosion inhibiting rate on carbon steel to up to 90%. The corrosion current density of carbon steel increased with increased temperature after volatilization of VCI. A closed container was carried out to mimic atmospheric corrosion condition, and its vapor corrosion inhibition property was evaluated in this closed container. Results showed that the VCI acted as an inhibitor by suppressing anodic dissolution and metallic ion transfer through the formation of protective film. It was also observed that the variation of carbon steel surface with volatilization of VCI was assessed by atomic force microscope (AFM) and scanning electron microscope (SEM). The anodic process for carbon steel without VCI affected the corrosion rate due to accumulation of corrosion products, while the morphology of carbon steel was hardly changed with volatilization of VCI. The results showed that the VCI volatilized to the surface and form to protect film. VCI was automatically volatilized into gas, which protected steel from corrosion. This composite VCI can then be applied as a significant corrosion inhibition method.

Electrolytic Aluminizing of Low-Carbon Steel in NaF-KF-AlF3 Melt

2015 ◽  
Vol 1088 ◽  
pp. 250-254 ◽  
Author(s):  
Yuriy Pavlovich Zaikov ◽  
Vadim Anatolyevich Kovrov ◽  
Irina Brodova ◽  
Yuriy Shtefanyuk ◽  
Vitaliy Pingin ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Oxidation Resistance ◽  
Current Density ◽  
Intermetallic Layer ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Good Oxidation Resistance ◽  
Intermetallic Coating ◽  
Aluminized Steel ◽  
Layer Composition

A multilayer intermetallic coating on low-carbon steel was obtained during aluminum electrodeposition in NaF-KF-AlF3 melt at 920 °C. The current density effect on morphology and intermetallic layer composition was investigated. Electrolytically aluminized steel samples represented a good oxidation resistance at 900 °C.

scholarly journals Effect of Different Operating Conditions on the Corrosion of Carbon Steel in Oxygenated Sodium Sulphate Solution

2013 ◽  
Vol 4 (3) ◽  
pp. 62-89
Author(s):  
Basim O. Hasan ◽  
Sara A. Sadek
Keyword(s):  
Carbon Steel ◽  
Corrosion Rate ◽  
Corrosion Product ◽  
Current Density ◽  
Considerable Increase ◽  
Rotational Velocity ◽  
Sodium Sulphate ◽  
Operating Conditions ◽  
Limiting Current ◽  
Limiting Current Density

 Carbon steel is a major metal used in manufacturing of the equipments used in petroleum industry and it is subject to different operating conditions causing various corrosion attacks. Corrosion of carbon steel in sodium sulphate solution (Na2SO4) under flow conditions was investigated using rotating cylinder electrode (RCE) for a range of rotation velocity (0 – 2000 rpm) and temperatures (32 - 52 oC). The corrosion rate  was determined by using both weight loss method and electrochemical polarization technique (limiting current density). Different salt concentrations were investigated ranged from 0.01 to 0.4 M. The effect of time (or corrosion product formation) and the effect of oxygen concentration through air bubbling in the solution were also investigated and discussed. The results showed that increasing  rotational velocity leads to a considerable increase in the corrosion rate represented by limiting current density. The corrosion rate had unstable trend with salt concentrations and temperature. Generally, the corrosion rate decreased appreciably with time due to the formation of corrosion product layer depending on rotational velocity, temperature, and oxygen concentration. It was found that, air pumping through the salt solution leads to a considerable increase in the limiting current density (iL) depending on rotational velocity, temperature, and time.

scholarly journals Causes of back-trap mottle in lithographic offset prints on coated papers

TAPPI Journal ◽  
2016 ◽  
Vol 15 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Gunnar ENGSTRÖM
Keyword(s):  
Mass Distribution ◽  
Evaporation Rate ◽  
Critical Concentration ◽  
Relaxation Times ◽  
Print Quality ◽  
Surface Porosity ◽  
Nonuniform Surface ◽  
Coating Surface ◽  
Coated Papers ◽  
Coating Mass

Back-trap mottle is a common and serious print quality problem in lithographic offset printing of coated papers. It is caused by nonuniform ink retransfer from an already printed surface when it passes through a subsequent printing nip with the print in contact with the rubber blanket in that nip. A nonuniform surface porosity gives rise to mottle. A key parameter in mottling contexts is the coating mass distribution, which must be uniform. Good relationships between mottle and mass distribution have also been reported; the mottle pattern coincides with that of the coating mass distribution. High blade pressures, compressible base papers, and high water pick-up between application and metering, which plasticizes the paper, yield uniform mass distributions, but these parameters might have a detrimental effect on the runnability in blade coating in terms of web breaks. The general opinion has been that nonuniform surface porosity is caused by binder migration and enrichment of binder in the coating surface, more in the high coat weight areas and less in the low coat weight areas. Recent research has suggested that a more probable mechanism is depletion of binder in the coating surface. Nonuniform shrinkage of the pigment matrix (filter cake) formed during the consolidation between the first critical concentration (FCC) and the second critical concentration (SCC) is another possible mechanism. Relevant relaxation times for latex and the time scales for consolidation show that the high coat weight areas shrink more than the low coat weight areas in the coating layer. A recent pilot-scale experiment has shown that the drying strategy did not affect the differences in shrinkage between high and low coat weight areas. The drying strategy has a pronounced impact on mottle. A high evaporation rate at the beginning of the evaporation results in less mottle than a low evaporation rate. The least mottle is obtained if the drying is performed with a gap in the course of evaporation between the FCC and the SCC.

Designing Lubricant-Impregnated Surfaces for Corrosion Protection

CORROSION ◽  
10.5006/3690 ◽  
2020 ◽  
Vol 76 (12) ◽  
Author(s):  
Sami Khan ◽  
Kripa K. Varanasi
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Corrosion Protection ◽  
Current Density ◽  
Corrosion Current Density ◽  
Silicone Oil ◽  
Corrosion Current

Corrosion is a detrimental process that can impact the performance and lifetime of many infrastructural systems. In this research, lubricant-impregnated surfaces (LIS) for corrosion protection are systematically developed and studied. Using microtextures with controlled geometry and spacing, this study shows that the corrosion resistance on LIS is greatly enhanced compared to bare iron as determined by a reduction in the corrosion current density by three orders of magnitude. Furthermore, it shows that the spreading characteristics of the lubricant are important toward ensuring effective corrosion protection. Krytox, a lubricant that covers both inside the textures as well as the top of the textures, provides two orders of magnitude greater corrosion protection as compared to silicone oil that does not cover texture tops. The practical applicability of LIS are highlighted to demonstrate corrosion protection on carbon steel in brine.

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