The effect of method of preparation on the corrosion resistance and catalytic activity during corrosion of tungsten carbide II. Changes in the catalytic activity of tungsten carbides during the corrosion process

1980 ◽  
Vol 5 (3) ◽  
pp. 283-290 ◽  
Author(s):  
I. Nikolov ◽  
T. Vitanov
Keyword(s):  
Corrosion Resistance ◽  
Catalytic Activity ◽  
Tungsten Carbide ◽  
Corrosion Process ◽  
Tungsten Carbides

Corrosion resistance and catalytic activity of tungsten carbide in phosphoric acid

1984 ◽  
Vol 12 (1) ◽  
pp. 1-8 ◽  
Author(s):  
V. Nikolova ◽  
I. Nikolov ◽  
T. Vitanov ◽  
L. Yotova
Keyword(s):  
Corrosion Resistance ◽  
Catalytic Activity ◽  
Phosphoric Acid ◽  
Tungsten Carbide

Corrosion Behavior of WC-Co and WC-Ni in 3.5% NaCl at Increasing Temperature

2014 ◽  
Vol 660 ◽  
pp. 135-139 ◽  
Author(s):  
A. Ismail ◽  
Norhaslina Abd Aziz
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Tungsten Carbide ◽  
Surface Structure ◽  
Tungsten Carbides ◽  
Corrosion Performance ◽  
Corrosion Attack ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Nickel Tungsten

Tungsten carbides (WC) are widely used as wear resistant components such as seal, valves, rings, nozzle and bearings. But in some processing operations, the environment necessarily includes severe corrosion or extremes of temperatures. In paper reveal, the corrosion performance of commercial cobalt tungsten carbide (WC-6%Co) and nickel tungsten carbide (WC-9%Ni) in seawater with 3.5% salinity. The experiment was performed in four different temperatures (20°C, 40°C, 60°C and 80°C) and the surface structure by corrosion attack was reveal under SEM. TheIcorrvalue of WC-9%Ni is lower than WC-6%Co, elucidate that WC-9%Ni is better in corrosion resistance compare to WC-6%Co. As the temperature increased, the corrosion rate for every material increased as expected. Decreasing in hardness value for both materials reveal that, the material’s hardness decrease after corrosion has attacked.

NIROSTA 4305

Alloy Digest ◽  
2002 ◽  
Vol 51 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tungsten Carbide ◽  
Tensile Properties ◽  
High Speed ◽  
High Speed Steel ◽  
Heat Treating ◽  
Austenitic Steels ◽  
High Sulfur Content ◽  
Machined Parts

Abstract NIROSTA 4305 is an austenitic alloy with a high sulfur content. The alloy is typically used for machined parts. As with other austenitic steels, it is necessary to machine with good-quality high-speed steel or tungsten carbide tools. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-854. Producer or source: ThyssenKrupp Nirosta GmbH.

scholarly journals Catalytic activity of Co-nanocrystal-doped tungsten carbide arising from an internal magnetic field

RSC Advances ◽  
2021 ◽  
Vol 11 (23) ◽  
pp. 14063-14070
Author(s):  
M. Morishita ◽  
A. Nozaki ◽  
H. Yamamoto ◽  
N. Fukumuro ◽  
M. Mori ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Catalytic Activity ◽  
Tungsten Carbide ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Pt Nanoparticles ◽  
Internal Magnetic Field ◽  
Co Doped

The catalytic activity of the Co-doped WC is 30% higher than that of Pt nanoparticles for the hydrogen evolution reaction arising from an internal magnetic field.

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.

Chromate and Molybdate Inhibitors Effects on Corrosion Charateristic of API 5L Grade B in a Brine Water Solution Containing 8 % NaCl

2021 ◽  
Vol 892 ◽  
pp. 115-123
Author(s):  
Viktor Malau ◽  
Wisnu Hakiki
Keyword(s):  
Corrosion Resistance ◽  
Oil And Gas ◽  
Corrosion Potential ◽  
Water Solution ◽  
Sodium Molybdate ◽  
Corrosion Process ◽  
Sodium Chromate ◽  
Polarization Method ◽  
Steel Pipes ◽  
Piping Systems

Piping systems at gathering stations in the oil and gas industries often fail due to corrosion attacks from the brine water solution containing 8% NaCl that flows through the system. This solution is highly corrosive on the API 5L grade B steel pipes, thereby shortening its lifespan, with an increase in the frequency of pipe replacements. However, the corrosion resistance of API 5L grade B pipes can be improved by using chromate and molybdate inhibitors. Therefore, the objective of this research is to improve the corrosion resistance of the steel pipes using sodium chromate (Na2CrO4) and sodium molybdate (Na2MoO4) inhibitors with concentrations of 0.2, 0.4, 0.6, 0.8 and 1,0%. This research also aim to determine the optimum concentration of inhibitors to produce minimum corrosion rate, by testing the brine water solution containing 8% NaCl through the potentiodynamic polarization method. The results show that generally, the addition of sodium chromate and sodium molybdate inhibitors to the brine solution causes the steel pipes to be more resistant to corrosion. Furthermore, the sodium chromate inhibitor concentration of 0.6% produces the greatest corrosion potential of – 400 mV with the lowest rate of 0.38 mpy, while sodium molybdate concentration of 0.4% produces the highest corrosion potential of – 385 mV with the lowest rate of 0.34 mpy. The results of SEM observations at 0.4% sodium molybdate concentration showed that the corrosion inhibition/passivation effect of the inhibitor made the steel surface smoother, while the sodium chromate inhibitor at similar percentage failed to reach the optimal concentration to inhibit 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.

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