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

scholarly journals Passivation Behavior of Steel Rod and Wires of Nepal in Acidic and Alkaline Solutions

1970 ◽  
Vol 9 ◽  
pp. 157-162
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Open Circuit Potential ◽  
Immersion Test ◽  
Open Circuit ◽  
Electrochemical Measurements ◽  
Alkaline Solutions ◽  
Alkaline Environments ◽  
Naoh Solution ◽  
Hcl Solution

The passivation behavior of steel rods and wires those are produced in Nepal was studied in 1 M HCl and 1 M NaOH solutions at 25°C, open to air using immersion tests and electrochemical measurements. The corrosion resistance of all the examined steel rods and wires in this work is found significantly higher in alkaline 1 M NaOH than in acidic 1 M HCl, mostly due to an ennoblement of the open circuit corrosion potentials of the steels at passive potential regions in 1 M NaOH solution at 25°C. The corrosion rate of all the examined steel rods and wires is about in the range of 1-5 x 101 mm/y in acidic 1 M HCl solution which is nearly three orders of magnitude lower corrosion resistance than in alkaline 1 M NaOH solution at 25°C. Therefore, these steel rods and wires seem to be very corrosion resistance materials in very alkaline environments like a reinforcing concrete. Key words: steels; corrosion rate; open circuit potential; immersion test; electrochemical measurements. DOI: 10.3126/njst.v9i0.3181 Nepal Journal of Science and Technology 9 (2008) 91-97

scholarly journals Effects of tungsten, chromium and zirconium on the corrosion behavior of ternary amorphous W–Cr–Zr alloys in 1 M NaOh solution

1970 ◽  
Vol 9 (9) ◽  
pp. 39-43
Author(s):  
Basu Ram Aryal ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Open Circuit Potential ◽  
Open Circuit ◽  
Corrosion Rates ◽  
Corrosion Resistance Property ◽  
Naoh Solution ◽  
Order Of Magnitude ◽  
Sputter Deposited ◽  
Zr Alloys

Simultaneous additions of tungsten, chromium and zirconium in the chromium- and zirconium-enriched sputter-deposited binary W-xCr and W-yZr are effective to improve the corrosion resistance property of the ternary amorphous W- xCr-yZr alloys after immersion for 240 h in 1 M NaOH solution open to air at 25°C. The corrosion rates of all the examined sputter-deposited (10-57)W-(18-42)Cr-(25-73)Zr alloys is higher than those of alloy-constituting elements (that is, tungsten, chromium and zirconium) in aggressive 1 M NaOH solution open to air at 25°C. The corrosion rates of all the examined sputter−deposited W–xCr–yZr alloys containing 10-57 at% tungsten, 18-42 at% chromium and 25-73 at% zirconium were in the range of 1.5-2.5 × 10−3 mm/y or lower which are more than two orders of magnitude lower than that of sputter-deposited tungsten and even about one order of magnitude lower than those of the sputter-deposited zirconium in 1 M NaOH solution. Keywords: Ternary W–Cr–Zr alloys; Amorphous; Corrosion rate; Open circuit potential; 1 M NaOH. DOI: http://dx.doi.org/10.3126/sw.v9i9.5516 SW 2011; 9(9): 39-43

scholarly journals An overview on the non-destructive in-depth surface analysis of corrosion-resistant films: A case study of W-xCr deposits in 12 M HCl solution

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 201-213
Author(s):  
Jagadish Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Depth Profiling ◽  
Surface Films ◽  
High Corrosion Resistance ◽  
Corrosion Rates ◽  
High Corrosion ◽  
Depth Analysis ◽  
Sputter Deposited ◽  
Non Destructive ◽  
Hcl Solution

Non-destructive in-depth analysis of the surface films formed on the sputter-deposited binary W-xCr (x = 25, 57, 91 at %) alloys in 12 M HCl solution open to air at 30 °C was investigated using an angle-resolved X-ray photoelectron spectroscopic (AR-XPS) technique to understand the synergistic corrosion resistance effects of showing very low corrosion rates, even lower than both alloying metals of the deposits. The average corrosion rates of these three tungsten-based sputter deposits found to be more than five orders of magnitude (between 3.1 × 10−3 and 7.2 × 10−3 mm/y) to that of chromium and also nearly one order of magnitude lower than that of tungsten metals. Such high corrosion resistance of the sputter-deposited W-xCr alloys is due to the formation of homogeneous passive double oxyhydroxide film consisting of Wox and Cr4+ cations without any concentration gradient in-depth after immersion in 12 M HCl solution open to air at 30 °C from the study of the non-destructive depth profiling technique of AR-XPS. Consequently, both alloying elements of tungsten and niobium are acted synergistically in enhancing high corrosion resistance properties of the alloys in such aggressive electrolyte. BIBECHANA 18 (2021) 201-213

scholarly journals The Corrosion Behavior of Sputter-Deposited Nanocrystalline W-Cr Alloys in Nacl and NaohaSolutions

1970 ◽  
Vol 25 ◽  
pp. 53-61
Author(s):  
Minu Basnet ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Chromium Content ◽  
Open Circuit ◽  
Nacl Solution ◽  
Corrosion Rates ◽  
Naoh Solution ◽  
Order Of Magnitude ◽  
Sputter Deposited

The corrosion behavior of the sputter-deposited nanocrystalline W-Cr alloys wasstudied in 0.5 M NaCl and alkaline 1 M NaOH solutions at 25°C, open to air usingimmersion tests and electrochemical measurements. Chromium metal acts synergisticallywith tungsten in enhancing the corrosion resistance of the sputter-deposited W-Cr alloys soas to show higher corrosion resistance than those of alloy-constituting elements in both 0.5M NaCl and 1 M NaOH solutions. In particular, the nanocrystalline W-Cr alloys containing25-91 at% chromium showed about one order of magnitude lower corrosion rates (that is,about 1-2 × 10-3 mm.y-1) than those of tungsten and chromium metals even for prolongedimmersion in 0.5 M NaCl solution at 25°C. On the other hand, the corrosion rate of thesputter-deposited W-Cr alloys containing 25-75 at % chromium was decreased significantlywith increasing chromium content and showed lowest corrosion rates (that is, 1.5-2.0 × 10-3 mm.y-1) after immersed for prolonged immersion in 1 M NaOH solution. The corrosion ratesof these nanocrystalline W-(25-75)Cr alloys are nearly two orders of magnitude lower thanthat of tungsten and more than one order of magnitude lower corrosion rate than that ofsputter-deposited chromium metal in 1 M NaOH solution. The corrosion-resistant of all theexamined sputter-deposited W-Cr alloys in 0.5 M NaCl solution is higher than in alkaline 1M NaOH solution at 25°C. Open circuit potentials of all the examined W-Cr alloys areshifted to more noble direction with increasing the chromium content in the alloys afterimmersion for 72 h in both 0.5 M NaCl and 1 M NaOH solutions at 25°C, open to air.Keywords: Sputter deposition, nanocrystalline W-Cr alloys, corrosion test, electrochemicalmeasurement, NaCl and NaOH solutions.DOI:  10.3126/jncs.v25i0.3300Journal of Nepal Chemical Society Volume 25, 2010 pp 53-61

Production of Metallurgically Cladded Pipes for High End Applications in the Oil and Gas Industry

2008 ◽  
Author(s):  
Thilo Reichel ◽  
Jochem Beissel ◽  
Vitaliy Pavlyk ◽  
Gernot Heigl
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Oil And Gas ◽  
Fem Analysis ◽  
Oil And Gas Industry ◽  
High Corrosion Resistance ◽  
Gas Industry ◽  
High Corrosion ◽  
Manufacturing Procedure ◽  
Longitudinal Welds

The paper describes the different industrially used options to produce a clad pipe and explains in detail the manufacture of metallurgically cladded pipes starting with the production of roll bonded plates. In plate manufacturing the advantages as well as the limitations of thermo-mechanical (TM) rolling are discussed. The TM-technology is shown to improve weldability, HIC-resistance, strength and toughness properties of the carbon steel section of the pipe. Moreover, it also improves corrosion resistance of the CRA layer. The pipe manufacturing procedure, which involves two welding technologies for longitudinal welds is described. The carbon steel parts of the pipe are joined using double-sided multi-pass Submerged-Arc-Welding (SAW). The single-pass Electroslag-Welding (ESW) is subsequently used for recladding of the CRA layer. The multi-pass SAW results in excellent mechanical properties of the weld joint, whereas the ESW technique ensures low dilution of CRA with the carbon steel, a smooth weld bead shape and a high corrosion resistance of the deposited layer. With the aid of thermodynamic modeling and numerical simulations it is shown, that the high corrosion resistance is promoted by an intensive mixing within the ESW weld pool and relatively low segregation level of Cr and Mo during solidification. Furthermore, FEM analysis is applied to examine the plastic deformation and residual stresses distribution in the pipe during forming, welding and final calibration. The obtained information assists in optimization of manufacturing procedure, and can also be included in prediction of resulting pipe fatigue during operation.

scholarly journals The Electrochemical Behavior of Carbon Steel Wires of Nepal in Different Environments

1970 ◽  
Vol 24 ◽  
pp. 31-38
Author(s):  
Jagadish Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Electrochemical Behavior ◽  
Steel Wire ◽  
Chemical Society ◽  
Open Circuit ◽  
Polarization Measurement ◽  
Steel Wires ◽  
Alkaline Environments ◽  
Naoh Solution

The electrochemical behavior of carbon steel wires of Nepal is studied in 1 M HCl, 0.5 M NaCl and 1 M NaOH solutions at 25°C, open to air using immersion tests and electrochemical measurements. The corrosion rates of the carbon steel wires were found to be about 20-50 mm/y in acidic 1 M HCl and 0.1-0.2 mm/y in neutral 0.5 M NaCl. The corrosion rate of all the examined steel wires in alkaline 1 M NaOH solution (that is, 7 - 18 x 10-3 mm/y) was found nearly three orders of magnitude lower corrosion resistance than in 1 M HCl solution at 25°C, mostly due to an ennoblement of the open circuit potentials of the steel wires at passive potential regions (that is, -200 to 250 mV vs SCE) in 1 M NaOH solution. The steel wires seem to be very corrosion resistance materials in very alkaline environments like cement-based materials. Keywords: Carbon steel wire; Corrosion tests; Polarization measurement; HCl;  NaCl and NaOH solutionsDOI: 10.3126/jncs.v24i0.2388Journal of Nepal Chemical Society Vol. 24, 2009 Page: 31-38   

scholarly journals Angle resolver X-ray photoelectron spectroscopic analysis of the passive film of the corrosion-resistant W-32Zr alloy in 12 M HCl solution

2015 ◽  
Vol 49 (2) ◽  
pp. 103-110
Author(s):  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Synergistic Effects ◽  
High Corrosion Resistance ◽  
Corrosion Resistant ◽  
X Ray ◽  
High Corrosion ◽  
Average Corrosion Rate ◽  
Sputter Deposited ◽  
Zirconium Metal ◽  
Hcl Solution

The sputter-deposited amorphous W-32Zr alloy was passivated spontaneously and showed a fairly high corrosion resistance in 12 M HCl solution in open air at 30°C. The average corrosion rate of the W-32Zr alloy (i.e., 5.2 × 10-3 mm/y) was found to be lower than those of alloy-constituting tungsten and zirconium elements. Such synergistic effects of simultaneous addition of tungsten and zirconium in the W–32Zr alloy was investigated by corrosion tests, electrochemical measurements and angle resolved X-ray photoelectron spectroscopic (ARXPS) analyses. High corrosion resistance of the binary W–32Zr alloy is mostly due to the formation of homogeneous passive oxyhydroxide film consisting of Wox and Zr4+ cations with a small concentration gradient in–depth from ARXPS analysis. Consequently, zirconium metal acts synergistically with tungsten in enhancing the anodic passivity as well as the corrosion resistance properties of the sputter–deposited W–32Zr alloy in 12 M HCl solution open to air at 30°C. DOI: http://dx.doi.org/10.3329/bjsir.v49i2.22004 Bangladesh J. Sci. Ind. Res. 49(2), 103-110, 2014

The Research of Electrochemical Properties of Al-Mg-Sn-Ga-Bi Alloys in Alkaline Electrolyte

2013 ◽  
Vol 800 ◽  
pp. 488-491 ◽  
Author(s):  
Jun Wei Gao ◽  
Jiu Ba Wen ◽  
Jun Guang He
Keyword(s):  
Corrosion Rate ◽  
Electrochemical Properties ◽  
Grain Boundaries ◽  
Open Circuit ◽  
The Self ◽  
Electrochemical Measurements ◽  
Alkaline Electrolyte ◽  
Naoh Solution

The microstructure and electrochemical properties of the Al-1Mg-0.1Sn-0.1Ga-xBi alloys were investigated by means of SEM/EDAX and electrochemical measurements, the self-corrosion was tested by using the gas-collecting method. The results show that element Bi in alloys is mainly segregated along the grain boundaries. The addition of Bi increases segregative phases which further activate the alloys to get more negative open circuit potentials, at the same time self-corrosion increases. Al-1Mg-0.1Sn-0.1Ga-0.1Bi has good comprehensive electrochemical properties, with ocp-1.693V (vs Hg/HgO) and self-corrosion rate 0.231 ml·cm-2 ·min-1 in 4 mol NaOH solution.

scholarly journals The Effects of Chromium and Nickel on the Passivation Behaviour of Sputter-Deposited W-Cr-Ni Alloys in 12 M HCl Solution

1970 ◽  
Vol 7 (7) ◽  
pp. 24-28
Author(s):  
Jagadesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Hydrogen Reduction ◽  
Open Circuit ◽  
Electrochemical Measurements ◽  
Corrosion Resistant ◽  
Ni Alloys ◽  
Scientific World ◽  
Sputter Deposited ◽  
Hcl Solution

The passivity of sputter-deposited ternary W-Cr-Ni alloys is investigated by immersion tests and electrochemical measurements in 12 M HCl solution at 30°C, open to air. Particular attention is paid to the effects of alloying elements to the corrosion behavior. All the examined amorphous or/and nanocrystalline W-Cr-Ni alloys are passivated spontaneously even in an aggressive environment of 12 M HCl, and hence these alloys showed higher corrosion resistance than those of alloyconstituting elements. The chromium addition suppresses the anodic dissolution current because of the formation of tetravalent chromium oxyhydroxide having a relatively high activity for both cathodic oxygen and hydrogen reduction with a consequent ennoblement of the open circuit potential. The ennoblement of the open circuit potential leads to the formation of the passive chromium oxyhydroxide film. It is, therefore, considered that the addition of chromium improves synergistically the corrosion resistance and passivating abilities of the sputter-deposited binary W-Ni alloys in 12 M HCl solution. Keywords: Sputter-deposition; Ternary W-Cr-Ni alloys; Corrosion-resistant; Electrochemical measurements. DOI: 10.3126/sw.v7i7.3819 Scientific World Vol.7(7) 2009 pp.24-28

scholarly journals The Corrosion Behavior of Sputter?deposited W?xTa Alloys in 0.5 M NaCl Solution

2013 ◽  
Vol 14 (1) ◽  
pp. 103-108
Author(s):  
Jagadeesh Bhattarai ◽  
Susil Baral
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Nacl Solution ◽  
High Corrosion Resistance ◽  
Positive Direction ◽  
Sputter Deposited

The corrosion behavior of the sputter–deposited amorphous and nanocrystalline W–xTa (x = 8–77) alloys was studied in 0.5 M NaCl solution open to air at 25°C using corrosion tests and electrochemical measurements. Tungsten and tantalum metals act synergistically in enhancing the corrosion resistance of the sputter–deposited W–xTa alloys and hence additions of 23 at. % of tantalum or more to the sputter–deposited W–xTa alloys were found to be effective to achieve significantly high corrosion resistance properties of the alloys than those of alloy– constituting elements. In particular, the corrosion rate of the W–60Ta alloy showed the lowest corrosion rate (that is, 2.0×10-3). The open circuit potential of the alloys shifted noble (positive) direction with immersion time. Addition of tantalum metal in W–xTa alloys is effective for ennoblement of the open circuit corrosion potential of the tungsten metal in 0.5 M NaCl solution open to air at 25°C. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 103-108 DOI: http://dx.doi.org/10.3126/njst.v14i1.8929

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