scholarly journals Synergistic Effect of Molybdate and Monoethanolamine on Corrosion Inhibition of Ductile Cast Iron in Tap Water

2017 ◽  
Vol 16 (1) ◽  
pp. 31-37 ◽  
Author(s):  
K.T. Kim ◽  
H.Y. Chang ◽  
B.T. Lim ◽  
H.B. Park ◽  
Y.S. Kim
Keyword(s):  
Cast Iron ◽  
Synergistic Effect ◽  
Corrosion Inhibition ◽  
Tap Water ◽  
Ductile Cast Iron

scholarly journals New Mechanism on Synergistic Effect of Nitrite and Triethanolamine Addition on the Corrosion of Ductile Cast Iron

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
K. T. Kim ◽  
H. Y. Chang ◽  
B. T. Lim ◽  
H. B. Park ◽  
Y. S. Kim
Keyword(s):  
Cast Iron ◽  
Synergistic Effect ◽  
Corrosion Inhibitors ◽  
Galvanic Corrosion ◽  
Tap Water ◽  
Immersion Test ◽  
Ductile Cast Iron ◽  
Ft Ir ◽  
Single Addition ◽  
Organic Inhibitor

In general, we compared the different inhibition mechanisms of organic inhibitor with that of anodic inhibitor. When triethanolamine or nitrite was added separately to tap water for inhibiting the corrosion of ductile cast iron, large amounts of inhibitor were needed. This is because the corrosion inhibitors had to overcome the galvanic corrosion that occurs between graphite and matrix. In this work, we investigated the corrosion of ductile cast iron in tap water with/without inhibitors. The corrosion rate was measured using chemical immersion test and electrochemical methods, including anodic polarization test. The inhibited surface was analyzed using EPMA and XPS. Test solutions were analyzed by performing FT-IR measurement. When triethanolamine and nitrite coexisted in tap water, synergistic effect built up, and the inhibition effect wasca.30 times more effective than witnessed with single addition. This work focused on the synergistic effect brought about by nitrite and triethanolamine and its novel mechanism was also proposed.

scholarly journals The Effect of Tungstate and Ethanolamines Added in Tap Water on Corrosion Inhibition of Ductile Cast Iron Pipe for Nuclear Power Plants

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1597
Author(s):  
Butaek Lim ◽  
Kitae Kim ◽  
Hyunyoung Chang ◽  
Heungbae Park ◽  
Youngsik Kim
Keyword(s):  
Cast Iron ◽  
Fire Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Tap Water ◽  
Ductile Cast Iron ◽  
Passivation Film ◽  
Fire Extinguishing ◽  
Immersion Corrosion

Cast iron is primarily used in buried piping to transport water in the fire protection system of nuclear power plants; ductile cast iron is generally used for domestic nuclear power plants. In general, the fluid used as fire-extinguishing water in such fire protection systems is tap water, and corrosion inhibitors are not currently added. In this study, the synergistic effect of an adsorption barrier (monoethanolamine) and oxidized film in an environment with a corrosion inhibitor (tungstate) is examined, and the corresponding passivation properties are presented. An immersion corrosion test and electrochemical test in tap water to which only tungstate was added showed suppression of corrosion compared to molybdate at the same concentration. The polarization resistance value of a passivation film in tap water mixed with monoethanolamine and tungstate showed better results than that of the molybdate control. A surface analysis in mixed addition tap water also demonstrated that oxygen ions were sufficiently distributed, including at some spheroidized graphite sites, when tungstate was added compared to molybdate. In addition, the amount of tungsten ions adsorbed on the surface was larger than that of molybdenum ions, and it was confirmed that tungsten ions were evenly distributed over the entire surface.

scholarly journals Moringa Oleifera Seed Oil as Green Corrosion Inhibitor for Ductile Cast Iron in Cassava Fluid

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Cast Iron ◽  
Corrosion Inhibition ◽  
Metal Surface ◽  
Moringa Oleifera ◽  
Seed Oil ◽  
Inhibition Efficiency ◽  
Ductile Cast Iron ◽  
Adsorption Studies ◽  
Increase With Increase ◽  
Moringa Oleifera Seed

Cassava fluid is acidic and corrodes the ductile cast iron parts from which many machineries used in processing cassava, a staple source of carbohydrates in most West African countries are made. The corrosion behavior of ductile cast iron cassava fluid with Moringa Oleifera seed oil as inhibitor was studied using 0, 0.2, 0.4, 0.6, and 0.8 %v/v concentrations and at two different temperatures of 40oC and 60oC by potentiodynamic polarization (Tafel) technique. Some thermodynamic, Corrosion inhibition and adsorption studies were also addressed. Moringa Oleifera seed oil extract was found to successfully inhibit the corrosion of cast iron in cassava fluid. Moringa Oleifera acted as a mixed type inhibitor. The corrosion inhibition efficiency was found to increase with increase in concentration of the extract but decrease with rise in temperature. The maximum inhibition efficiency of the extract on ductile cast iron corrosion was noted to be about 73%. Adsorption studies showed that Langmuir isotherm describes the manner in which the inhibitor was adsorbed on the metal surface. The adsorption process was found to be spontaneous as all the free energy of adsorption values calculated were negative and ranged from -3.43 kJ/mol to -1.34 kJ/mol, signifying a spontaneous physical adsorption on metal surface. The stereo-micrograph images of the metal surface after immersion in corrosive medium confirmed the protection offered by the Moringa Oleifera extract on the surface of the metal. It was further shown that the corrosion rate was influenced by the combined interactions of temperature of operation and concentration of the inhibitor.

Variation of biofilm formation on distribution pipe depending on water treatment processes and pipe materials

2007 ◽  
Vol 7 (4) ◽  
pp. 25-35 ◽  
Author(s):  
J.E. Shin ◽  
M.J. Jang ◽  
J.Y. Koo ◽  
S.K. Ahn ◽  
M.J. Yu
Keyword(s):  
Cast Iron ◽  
Water Treatment ◽  
Biofilm Formation ◽  
Tap Water ◽  
Ductile Cast Iron ◽  
Plate Count ◽  
Pipe Material ◽  
Treatment Processes ◽  
Identification Of Species ◽  
Pipe Materials

Biofilms may appear as a patchy mass in some pipe sections and may lead to deterioration of bacterial water quality, amplification of corrosion, and generation of bad tastes and odors. Characteristics of biofilm formation were studied depending on pipe materials, water treatment processes and temperature. From the results of this study, on the whole, HPC (heterotrophic plate count) increased with lapse of time and decreased according to decrease of temperature. The highest HPC showed on CIP (cast iron pipe) material for all treatment processes. The lowest HPC showed on CIPP (cured in place pipe) liner and SSP (stainless steel pipe) material. The high HPC showed in the pipe feeding tap water. The mean HPC of room temperature was higher than that of low temperature. The results of pilot test, the HPC of DCIP (ductile cast iron pipe) was higher than that of CIPP. The results of investigation on the field, we could see correlation between AOC concentration of tap water on the field and the HPC in tubercle. In the identification of species in biofilm, on the whole, Pseudomonas spp. dominated.

scholarly journals Effect of Ethanolamines on Corrosion Inhibition of Ductile Cast Iron in Nitrite Containing Solutions

2016 ◽  
Vol 15 (4) ◽  
pp. 171-181 ◽  
Author(s):  
K.T. Kim ◽  
H.Y. Chang ◽  
B.T. Lim ◽  
H.B. Park ◽  
Y.S. Kim
Keyword(s):  
Cast Iron ◽  
Corrosion Inhibition ◽  
Ductile Cast Iron

Influence of casting skin on the fatigue lifetime of ferritic ductile cast iron

2017 ◽  
Vol 59 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Birgit Rehmer ◽  
Birgit Skrotzki ◽  
Steffen Glaubitz
Keyword(s):  
Cast Iron ◽  
Ductile Cast Iron ◽  
Fatigue Lifetime ◽  
Casting Skin
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