scholarly journals Diagnostics of Temperature Regime of Technological Environments of Underground Pipelines in the Monitoring System of Oil and Gas Enterprises for Providing of Safe Exploitation

2020 ◽  
Vol 9 (1) ◽  
pp. 1301-1307
Keyword(s):  
Density Distribution ◽  
Current Density ◽  
Corrosion Current Density ◽  
Oil And Gas ◽  
Current Density Distribution ◽  
Corrosion Current ◽  
Compressor Station ◽  
Underground Pipelines ◽  
Heat Pulses ◽  
Thermal Pulses

The diagnosed density of corrosion was diagnosed on the outer surface of the underground metal pipeline, depending on the distance L to the compressor station, taking into account the influence of soil, defects, thermal impulses, mechanical vibrational vibrations and corrosion fatigue. The basic relations of the mathematical model for the description of thermal processes and mechanical vibrational vibrations that lead to low-cycle corrosion fatigue in the pipe are proposed. It is noted that the measurement of corrosion currents and polarization potentials at the boundary of the metal pipeline–soil can be detected by devices of types BVS (noncontact current meter), VPP-M (polarization potential meter) and equipment for for diagnostic inspections and monitoring of corrosion protection of underground pipelines (UGPL). Consider for compare the distribution of corrosion current densities and accidents for the pipeline at a distance of L=0..30 km from the compressor station. It is found that the correlation coefficient between them KLD=0,76 is not enough to establish causation. A difference is formed in which the corresponding corrosion current density distribution for a non-oscillating temperature background is subtracted from the total corrosion current density distribution in the range L=0…30 km. In this case, the part of the distribution that is related to the frequency of thermal pulses is highlighted.The correlation coefficient of KWD0.92 is established between the part of the distribution that is related to the frequency of thermal pulses and the distribution of accidents for the pipeline at a distance of L=0…30 km from the compressor station. Based on KWD, it can be argued that the causal relationship between the distribution of heat pulses and accidents is quite plausible. The noted information is important for improving the methods of operation of compressor stations of oil and gas enterprises, taking into account changes in the frequency of heat pulses with regard to improving the quality of by-laws on labor protection regarding gas supply systems

Energy Balance on Current Density Distribution of Cathode Spot in Vacuum Arc

2019 ◽  
Vol 139 (5) ◽  
pp. 302-308 ◽  
Author(s):  
Shinji Yamamoto ◽  
Soshi Iwata ◽  
Toru Iwao ◽  
Yoshiyasu Ehara
Keyword(s):  
Energy Balance ◽  
Density Distribution ◽  
Current Density ◽  
Cathode Spot ◽  
Current Density Distribution ◽  
Vacuum Arc

Automated Measurement of the Spatial Current Density Distribution of Process Electron Beams

Vestnik MEI ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 72-79
Author(s):  
Aleksey S. Kozhechenko ◽  
◽  
Aleksey V. Shcherbakov ◽  
Regina V. Rodyakina ◽  
Daria A. Gaponova ◽  
...  
Keyword(s):  
Density Distribution ◽  
Current Density ◽  
Electron Beams ◽  
Current Density Distribution ◽  
Automated Measurement ◽  
Spatial Current

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

scholarly journals Structure, Corrosion Resistance, Mechanical and Tribological Properties of ZrB2 and Zr-B-N Coatings

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1194
Author(s):  
Philipp Kiryukhantsev-Korneev ◽  
Alina Sytchenko ◽  
Yuriy Kaplanskii ◽  
Alexander Sheveyko ◽  
Stepan Vorotilo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Tribological Properties ◽  
Current Density ◽  
Corrosion Current Density ◽  
Elastic Recovery ◽  
Optical Emission ◽  
Corrosion Current ◽  
Impact Testing ◽  
Total Oxidation ◽  
Mechanical And Tribological Properties

The coatings ZrB2 and Zr-B-N were deposited by magnetron sputtering of ZrB2 target in Ar and Ar–15%N2 atmospheres. The structure and properties of the coatings were investigated via scanning and transmission electron microscopy, energy dispersion analysis, optical profilometry, glowing discharge optical emission spectroscopy and X-ray diffraction analysis. Mechanical and tribological properties of the coatings were investigated using nanoindentation, “pin-on-disc” tribological testing and “ball-on-plate” impact testing. Free corrosion potential and corrosion current density were measured by electrochemical testing in 1N H2SO4 and 3.5%NaCl solutions. The oxidation resistance of the coatings was investigated in the 600–800 °С temperature interval. The coatings deposited in Ar contained 4–11 nm grains of the h-ZrB2 phase along with free boron. Nitrogen-containing coatings consisted of finer crystals (1–4 nm) of h-ZrB2, separated by interlayers of amorphous a-BN. Both types of coatings featured hardness of 22–23 GPa; however, the introduction of nitrogen decreased the coating’s elastic modulus from 342 to 266 GPa and increased the elastic recovery from 62 to 72%, which enhanced the wear resistance of the coatings. N-doped coatings demonstrated a relatively low friction coefficient of 0.4 and a specific wear rate of ~1.3 × 10−6 mm3N−1m−1. Electrochemical investigations revealed that the introduction of nitrogen into the coatings resulted in the decrease of corrosion current density in 3.5% NaCl and 1N H2SO4 solution up to 3.5 and 5 times, correspondingly. The superior corrosion resistance of Zr-В-N coatings was related to the finer grains size and increased volume of the BN phase. The samples ZrB2 and Zr-B-N resisted oxidation at 600 °C. N-free coatings resisted oxidation (up to 800 °С) and the diffusion of metallic elements from the substrate better. In contrast, Zr-B-N coatings experienced total oxidation and formed loose oxide layers, which could be easily removed from the substrate.

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