Corrosion Behavior of Al2O3 Ceramics in the Acid and Alkaline Solutions

2012 ◽  
Vol 512-515 ◽  
pp. 509-512 ◽  
Author(s):  
Long Huang ◽  
Shan Shan Luo ◽  
Wen Kui Li
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Sea Water ◽  
Working Life ◽  
Corrosion Process ◽  
Alkaline Solutions ◽  
Acid Solutions ◽  
Wide Range ◽  
Alkaline Conditions ◽  
Corrosion Time

Al2O3 materials were used in a very wide range due to its good mechanical properties and relative low manufacture cost. The corrosion resistance of Al2O3 materials in acid, alkaline and sea water solutions gained more and more attention because many application situations are severe and the working life is shorten due to the corrosion. In this paper, the corrosion behavior of Al2O3 based materials in acid and alkaline solutions was studied and effect of corrosion time on the corrosion behavior of Al2O3 materials was investigated. The microstructure of as prepared Al2O3 materials was characterized by SEM. Possible corrosion process and mechanism was discussed in details. The results reveal that the as prepared Al2O3 materials show better corrosion resistance in alkaline solution than in acid solutions. In both acid and alkaline conditions, the corrosion mainly occurs in the grain boundary. Mass loss increased with increasing corrosion time, while the corrosion rate was decreased.

Evaluation of the corrosion behavior of AZ31 magnesium alloy with different protein concentrations

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yucong Ma ◽  
Mohd Talha ◽  
Qi Wang ◽  
Zhonghui Li ◽  
Yuanhua Lin
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Surface Film ◽  
Energy Dispersive Spectrometer ◽  
Inhibitory Effect ◽  
Corrosion Process ◽  
High Concentration ◽  
Content Type ◽  
Atomic Force

Purpose The purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L). Design/methodology/approach Electrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film. Findings Experimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance. Originality/value When the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.

Corrosion behavior of new type Co-based superalloys with different Ni contents

2017 ◽  
Vol 35 (6) ◽  
pp. 455-462 ◽  
Author(s):  
Bo Gao ◽  
Lei Wang ◽  
Yang Liu ◽  
Xiu Song ◽  
Shu-Yu Yang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Corrosion Layer ◽  
Corrosion Process ◽  
Corrosion Properties ◽  
Oxidation Processes ◽  
Ni Content ◽  
Ni Addition ◽  
New Type

AbstractThe corrosion properties of γ′-strengthened Co-xNi-Al-W-Cr (where x=15, 20, 25, and 30 at.%) superalloys were investigated in the mixture of 75 wt.% Na2SO4+25 wt.% NaCl at 900°C. The results showed that the corrosion behavior is associated with both sulfuration and oxidation processes. It was demonstrated that increasing the addition of Ni effectively promoted the formation of continuous Al2O3 scales, so that the hot corrosion resistance could be improved. When Ni content is more than 20 at.%, a large amount of Ni3S2 precipitates during the corrosion process. Sulfuration can destroy the integrity of the corrosion layer and increase the activity of oxygen. In this way, the internal oxidation of the alloys becomes more serious. Therefore, it is recommended that the optimum Ni addition is about 20 at.% for new type Co-Ni-Al-W-Cr superalloys.

scholarly journals The effect of time variation on the steels corrosion rate in 0.5 M H2SO4 solution

2021 ◽  
Vol 1 (2) ◽  
pp. 49-55
Author(s):  
Afira Ainur Rosidah ◽  
Vuri Ayu Setyowati ◽  
Suheni Suheni ◽  
Rafly Rijayanto
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Time Variation ◽  
H2so4 Solution ◽  
Steel Type ◽  
Wide Range ◽  
Aisi 4140 ◽  
Aisi 1045 ◽  
Ss 304 ◽  
Corrosion Time

Previous researches have carried out studying the corrosion behavior of steels, the most frequently used steels are medium carbon steel, alloy steel, and stainless steel. This is due to their wide range of applications. So, corrosion behavior is necessary to be analyzed for every steel type because of its wide function. This study was aimed to analyze the corrosion rate, macrostructure, and the XRD results of the AISI 1045, AISI 4140, and SS 304 which represent every steel type. Then, the steels were exposed to the 0.5M H2SO4 solution with various corrosion times. The variation of the corrosion time was 48, 96, and 144 hours. The results of this study revealed that AISI 1045 showed the highest corrosion rate with the value of 183.7 mpy at 144 hours of the time variation. All specimens obtained an increase in the corrosion rate with the increase in the corrosion time. Furthermore, for the macrostructure results, AISI 1045 and AISI 4140 gave obvious rust on the surface of the specimens for all time variation. The corrosion spots appear in the time variation of 96 and 144 hours for SS 304 specimens. XRD analysis confirmed the presence of metal oxides as corrosion products.

Phenolic resin derived from Jatropha curcas seed-husk lignin as phenol substitute

1969 ◽  
Vol 7 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Carlos Alberto Vega-Aguilar ◽  
Giselle Lutz ◽  
Julio F. Mata-Segreda
Keyword(s):  
Jatropha Curcas ◽  
Phenolic Resin ◽  
Physical Stability ◽  
Alkaline Solutions ◽  
Phenolic Resins ◽  
Good Opportunity ◽  
Alkaline Pulping ◽  
Wide Range ◽  
Alkaline Conditions ◽  
Seed Husk

Phenolic resin derived from Jatropha curcas seed-husk lignin as phenol substitute. A phenolic resin was made, with a fraction of the phenol content substituted by lignin extracted from Jatropha curcas seed husk. The husk was analysed for chemical composition, finding a high quantity of lignin (47% mass fraction). This lignin was extracted using an alkaline pulping method, followed by precipitation with acid. Several lignin-modified phenolic resins were made, using different lignin contents, in mixtures with formaldehyde in alkaline conditions, and curing at 65 ºC for 6 hours. It was noticed that the lignin substitution percentage affects the resin’s mechanical properties, obtaining better results with a 50% substitution. These resins showed good thermal behaviour, electrical insulation properties and good physical stability against water, acidic solutions and organic solvents, but it lacked on stability against alkaline solutions. It is concluded that there is a good opportunity for using the J. curcas seed husk lignin as partial substitute of phenol in phenolic resins, without sacrificing their physicochemical properties. There is a wide range of possibilities on using J. curcas agro-industrial residues as a renewable feedstock. 

Corrosion behaviour of Mn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials

2013 ◽  
Vol 60 (5) ◽  
pp. 234-238
Author(s):  
Yan Jing ◽  
Chao Zhang ◽  
Jun Ma ◽  
Yongzhong Jia
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Design Methodology ◽  
Room Temperature ◽  
Corrosion Behaviour ◽  
Corrosion Process ◽  
Al Alloy ◽  
Content Type ◽  
Explosion Suppression ◽  
Strengthening Phases

PurposeThe purpose of this paper is to prepare the Mn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials, and determine the corrosion behavior of aluminum alloy explosion suppression materials in HCl and NaOH solutions. The different mechanism of corrosion was discussed.Design/methodology/approachIn this paper, Mn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials were prepared, and the electrochemical behavior of the EAESM was studied. The corrosion parameters were calculated and the mechanism of the corrosion process was discussed. The corrosion behavior was characterized by immersion tests and SEM at room temperature.FindingsMn‐Si‐Fe‐Cu‐Al alloy explosion suppression materials have been prepared. SEM, the polarization curves showed that materials have corrosion resistance. The best content of Al alloy is Mn 0.880%, Si 0.135%, Fe 0.383% and Cu 0.0835%.Originality/valueThe results of this investigation show that adding alloying elements can form new strengthening phases that influence the corrosion resistance of alloys.

Effect of Sulfur and Chlorine on Fireside Corrosion Behavior of Inconel 740 H Superalloy

2018 ◽  
Vol 37 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Lu Jin-tao ◽  
Li Yan ◽  
Yang Zhen ◽  
Huang Jin-yang ◽  
Zhu Ming ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Film ◽  
Corrosion Behavior ◽  
Flue Gas ◽  
Coal Ash ◽  
Corrosion Process ◽  
Fireside Corrosion

AbstractFireside corrosion behavior of Inconel 740H superalloy was studied at 750 °C in simulated coal ash/flue gas environments by means of XRD, SEM and EDS. The results indicated that the corrosion behavior was strongly related to the SO2 levels and was significantly affected by NaCl additions. In presence of the atmospheres with 0.1 % SO2, the alloy exhibited the highest corrosion resistance due to formation of a stable and dense Cr2O3 film. In presence of the atmosphere with 1.5 % SO2, however, a non-coherent and porous Cr2O3 film was formed. The thickness of film and internal sulfides were substantially increased. The NaCl additions significantly accelerated the corrosion process. A non-protective outer oxide film was formed, composed by multiple layers with serious inner sulfide and spallation. The depths of internal oxidizing and sulfuration zones were significantly increased. The mechanism of ash corrosion formation was also discussed.

scholarly journals Effect of Ca Addition on Corrosion Behavior of Wrought AM60 Magnesium Alloy in Alkaline Solutions

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1172
Author(s):  
Polina Metalnikov ◽  
Guy Ben-Hamu ◽  
Kwang Seon Shin ◽  
Amir Eliezer
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Fuel Efficiency ◽  
Electrochemical Corrosion ◽  
Alkaline Solutions ◽  
Kelvin Probe ◽  
Ca Addition ◽  
Electrochemical Corrosion Behavior

Magnesium (Mg) alloys possess the lowest density among structural materials, and their application in the automotive and aircraft industries might enhance fuel efficiency. The mechanical properties can be improved by the addition of alloying elements. However, since Mg and its alloys are very susceptible to corrosion degradation, it is important to study the effect of these elements on the alloys’ corrosion behavior. In this study, 1 wt% of calcium (Ca) was added to wrought AM60 Mg alloy, and the electrochemical corrosion behavior of the alloys in alkaline solutions with and without Cl− ions was compared. The corrosion behavior was investigated by means of immersion tests, gravimetric measurements and potentiodynamic polarization (PDP); the characteristics of the oxide layer were studied by electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS). The addition of Ca resulted in precipitation of the ternary aluminum-rich (Mg-Al)2Ca phase. Scanning Kelvin probe force microscope (SKPFM) identified that this phase has a cathodic behavior relative to the α-Mg matrix; hence it can serve as additional sites for initiation of pitting corrosion. As a result, the corrosion resistance of wrought AM60 alloy with 1 wt% Ca addition deteriorated in a NaCl solution. However, in the absence of Cl− ions, alloying with Ca improves the corrosion resistance of wrought AM60 alloy due to the stabilization of the corrosion products layer. The effect of long-period immersion time on the corrosion behavior and alloy oxidation is discussed.

Corrosion Behaviour of Anodised Powder Metallurgy Aluminium-Magnesium Composites

2013 ◽  
Vol 795 ◽  
pp. 469-473
Author(s):  
Kamrosni Abdul Razak ◽  
Mohd Nazree Derman
Keyword(s):  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Sulphuric Acid ◽  
Corrosion Behavior ◽  
Potentiodynamic Polarization ◽  
Corrosion Behaviour ◽  
Short Fibre ◽  
Acid Solutions ◽  
Powder Metallurgy Route ◽  
Magnesium Composites

The corrosion behavior of anodized powder metallurgy Al/2wt%Mg composites reinforced with the short fibre alumina SaffilTM was studied using potentiodynamic polarization in 3.5% NaCl solutions. The materials under investigation were fabricated using powder metallurgy route. Anodising process has been done to the materials to improve their corrosion resistance. Anodising process were carried out in sulphuric acid solutions with different anodizing voltage, which are 10V, 12V, 14V, 16V and 18V and different concentration of sulphuric acid (5%, 10%, 15%, 20% and 25%). Results from Tafel plot showed that corrosion behavior of PM Al-Mg composites strongly depends on the anodizing parameters. Corrosion resistance increases with the increase in anodizing voltage and concentration of sulphuric acid. The maximum corrosion resistance was recorded by the PM Al-Mg composite anodized using 16V and in the 15% concentration of sulphuric acid.

The Corrosion Resistance of Ductile Iron In Sea Water and Petroleum Tanker Services★

CORROSION ◽  
1957 ◽  
Vol 13 (5) ◽  
pp. 22-26 ◽  
Author(s):  
MICHEL PARIS ◽  
B. de la BRUNIERE
Keyword(s):  
Corrosion Resistance ◽  
Ductile Iron ◽  
Sea Water ◽  
Laboratory Data ◽  
Gray Iron ◽  
Acid Solutions ◽  
Product Lines

Abstract Laboratory data are given which compare the corrosion resistance of gray iron, steel and ductile iron in sea water and various acid solutions of different concentrations. Data also are presented to show the performance of ductile iron when used for product lines on petroleum tankers. Of particular interest is information presented for a low alloyed ductile iron which has given complete satisfaction under highly aggressive conditions in petroleum tanker service. 6.2.2

Effects of Rare Earth on Electrochemical Corrosion Behavior of Graphite-Like Carbon Coatings

2011 ◽  
Vol 199-200 ◽  
pp. 1978-1983
Author(s):  
Zuo Ping Wang ◽  
Peng Bo Chen ◽  
Zhong Wei Ma ◽  
Jiang Tao Yu Wen
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Surface Layer ◽  
Corrosion Behavior ◽  
Current Density ◽  
Sea Water ◽  
Electrochemical Corrosion ◽  
Form Complex ◽  
Carbon Coatings ◽  
Electrochemical Corrosion Behavior

The corrosion behavior of graphite-like carbon (GLC) coating in sea water was studied and yttrium and cerium were doped into it by using mosaic in the target of magnetron sputtering process to improve its corrosion resistance. The result shows that the GLC coating characterizes typical underfilm electrochemical corrosion in sea water. Yttrium added in chromium interlayer or yttrium and cerium added in the surface layer of the GLC coating can apparently improve the microstructure result in significantly decrease the corrosive current density. As the modifications of Y in interlayer and Y, Ce and Ta in top layer are composed together to form complex GLC coating, the wear resistance and the antifriction is dramatically improved, the corrosive current density is only one-twenty fourth of that of the commercial C/Cr GLC coating.

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