The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

Frank Y Cheng - One of the best experts on this subject based on the ideXlab platform.

  • effect of roughness on General Corrosion and pitting of fecocrni 0 89 wc 0 11 high entropy alloy composite in 3 5 wt nacl solution
    Corrosion Science, 2019
    Co-Authors: Qian Li, Frank Y Cheng
    Abstract:

    Abstract The influence of roughness on General Corrosion and pitting of (FeCoCrNi)0.89(WC)0.11 high-entropy alloy composite in 3.5 wt.% NaCl solution was studied by electrochemical measurements and composition characterization. The results showed that a dual-layer passive film formed on WC-HEA composite, and its stability and compactness increased with the decreased roughness. The predominant Corrosion type of the composite changed from General Corrosion to pitting with the decrease of roughness. Galvanic Corrosion occurred between the FCC phase (cathode) and Cr-rich carbide (anode) on the smooth composite surface, inducing the pitting initiation and development of the Cr-rich carbide at the two-phase interface.

Heesang Shim - One of the best experts on this subject based on the ideXlab platform.

  • effect of electropolishing on General Corrosion of alloy 690tt tubes in simulated primary coolant of pressurized water reactors
    Applied Surface Science, 2019
    Co-Authors: Heesang Shim
    Abstract:

    Abstract The purpose of this study is to investigate the effect of electropolishing (EP) time on the General Corrosion of Alloy 690TT steam generator tubes in a simulated PWR primary water of at 330 °C. The surface roughness and nanohardness of the tubes gradually decreased, and the electron work function and water contact angle gradually increased with increasing the EP time. However, the effect of EP time on the surface properties mainly changed after 8 min. The Corrosion rate was reduced through EP treatment by approximately 60% compared to that of the commercial as-received tube.

  • a prediction method for the General Corrosion behavior of alloy 690 steam generator tube using eddy current testing
    Nuclear Engineering and Design, 2016
    Co-Authors: Heesang Shim, Myung Sik Choi
    Abstract:

    Abstract The purpose of this work is to develop an eddy current testing method to predict the General Corrosion behavior of Alloy 690 steam generator tubes. A Corrosion test was conducted for tubes with different levels of eddy current noise in simulated primary water at 330 °C, and their Corrosion behavior was correlated with the tube noise measured using bobbin and rotating probes. The Corrosion behavior was closely correlated with the tube noise measured using a rotating probe. However, there was no correlation between the Corrosion behavior and the tube noise measured using a bobbin probe. The tube noise value measured using a rotating pancake coil probe is suggested to be a significant parameter in estimating the General Corrosion behavior of tubes.

Zhang Dongshan - One of the best experts on this subject based on the ideXlab platform.

  • Residual strength calculation & residual life prediction of General Corrosion pipeline
    Procedia Engineering, 2014
    Co-Authors: Zhang Dongshan
    Abstract:

    General Corrosion is of the primary reason that causes the pipeline to failure. Researching the residual strength and residual life of General Corrosion pipeline is the main measure to conduct the pipeline integrity management, and has great significance to ensure the safety of pipeline transportation. The calculation of the residual strength of even Corrosion pipeline under the combined effects of internal pressure and axial force was discussed according to the Tresca yield criterion in elasto-plastic fault mechanics, when the defected size is given, the maximum permissible operating pressure under the defect and the calculation formula for the residual strength of Corrosion pipeline are given. On this basis, reliability-based residual life prediction of the Corrosion pipeline was developed.

  • residual strength calculation residual life prediction of General Corrosion pipeline
    Procedia Engineering, 2014
    Co-Authors: Zhang Dongshan
    Abstract:

    Abstract General Corrosion is of the primary reason that causes the pipeline to failure. Researching the residual strength and residual life of General Corrosion pipeline is the main measure to conduct the pipeline integrity management, and has great significance to ensure the safety of pipeline transportation. The calculation of the residual strength of even Corrosion pipeline under the combined effects of internal pressure and axial force was discussed according to the Tresca yield criterion in elasto-plastic fault mechanics, when the defected size is given, the maximum permissible operating pressure under the defect and the calculation formula for the residual strength of Corrosion pipeline are given. On this basis, reliability-based residual life prediction of the Corrosion pipeline was developed.

Tiehu Li - One of the best experts on this subject based on the ideXlab platform.

  • Corrosion behavior of oil tube steel in simulant solution with hydrogen sulfide and carbon dioxide
    Materials Chemistry and Physics, 2005
    Co-Authors: Tiehu Li
    Abstract:

    Electrochemical measurement techniques, X-ray diffraction and scanning electron microscopy were applied to investigate the Corrosion behavior of N80 tube steel in simulant static solution with carbon dioxide (CO2) and hydrogen sulfide (H2S) at a temperature of 100 °C. Sweet Corrosion occurred when a very small partial pressure of H2S was added. At this condition, uniform Corrosion was found. The added H2S only accelerated the General Corrosion rate. Sour Corrosion was primary as the partial pressure of H2S increased to 0.010 MPa. The General Corrosion rate decreased quickly, but severe pitting was found. The Corrosion scale, mainly composed of coarse grains of mackinawite (FeS1−x), was loose and brittle. In sour Corrosion, General Corrosion rate decreased slowly and pitting became slight with increasing partial pressure of H2S because the primary Corrosion product, fine grains of pyrrhotite (FeS1+x), made the scale more compact and continuous.

  • Corrosion behavior of oil tube steel in simulant solution with hydrogen sulfide and carbon dioxide
    Materials Chemistry and Physics, 2005
    Co-Authors: Chengqiang Ren, Zhenquan Bai, Daoxin Liu, Tiehu Li
    Abstract:

    Electrochemical measurement techniques, X-ray diffraction and scanning electron microscopy were applied to investigate the Corrosion behavior of N80 tube steel in simulant static solution with carbon dioxide (CO2) and hydrogen sulfide (H2S) at a temperature of 100 °C. Sweet Corrosion occurred when a very small partial pressure of H2S was added. At this condition, uniform Corrosion was found. The added H2S only accelerated the General Corrosion rate. Sour Corrosion was primary as the partial pressure of H2S increased to 0.010 MPa. The General Corrosion rate decreased quickly, but severe pitting was found. The Corrosion scale, mainly composed of coarse grains of mackinawite (FeS1-x), was loose and brittle. In sour Corrosion, General Corrosion rate decreased slowly and pitting became slight with increasing partial pressure of H2S because the primary Corrosion product, fine grains of pyrrhotite (FeS1+x), made the scale more compact and continuous. © 2005 Elsevier B.V. All rights reserved.

Jan Macák - One of the best experts on this subject based on the ideXlab platform.

  • european project supercritical water reactor fuel qualification test summary of General Corrosion tests
    Journal of Nuclear Engineering and Radiation Science, 2016
    Co-Authors: Radek Novotný, Přemysl Janík, Aki Toivonen, Anna Ruiz, Zoltan Szaraz, Lefu Zhang, Jan Siegl, Petr Haušild, Sami Penttilä, Jan Macák
    Abstract:

    The main target of the EUROATOM FP7 project “Fuel Qualification test for SCWR” is to make significant progress towards the design, analysis and licensing of a fuel assembly cooled with supercritical water in a research reactor. The program of dedicated WP4 - Pre-qualification was focused on evaluation of General Corrosion resistance of three pre-selected austenitic stainless steels 08Cr18Ni10Ti, AISI 347H and AISI 316L, which should be pre-qualified for application as a cladding material for fuel qualification tests in supercritical water. Therefore, the experiments in support of WP4 concentrated on 2000 h Corrosion exposures in 25 MPa SCW at two different temperatures 550 and 500°C dosed with both 150 and 2000 ppb of dissolved oxygen content. Moreover, water chemistry effect was investigated by conducting tests in 550°C SCW with 1.5 ppm of dissolved hydrogen content. At first, Corrosion coupons were exposed for 600, 1400 and 2000 h in JRC IET, VTT and SJTU autoclaves connected to recirculation loop allowing continual water chemistry control during the test. Following examination of the exposed specimens consisted of weight change calculations and detailed macro and microscopic investigation of oxide layers using SEM and EDX. With respect to General Corrosion results, all tested steels showed sufficient Corrosion resistance in SCW conditions taking into account the conditions foreseen for future fuel qualification test in the research reactor in CVR Rez. When the results of weight change calculations were compared for all three materials, it was found out, that the Corrosion resistance increased in the following order: 316L<347H<08Cr18Ni10Ti. Results obtained in hydrogen water chemistry did not indicate any significant beneficial effect compared to tests in SCW with 150 or 2000 ppb dissolved oxygen content. Additional tests were dedicated to investigation of surface finish effect. In these exposures polished, sand-blasted and plane-milled surface finish technique were investigated. Beneficial effect of surface cold work in particular of sand-blasting was clearly demonstrated.

  • European Project “Supercritical Water Reactor-Fuel Qualification Test”: Summary of General Corrosion Tests
    Journal of Nuclear Engineering and Radiation Science, 2016
    Co-Authors: Radek Novotný, Přemysl Janík, Aki Toivonen, Anna Ruiz, Zoltan Szaraz, Lefu Zhang, Jan Siegl, Petr Haušild, Sami Penttilä, Jan Macák
    Abstract:

    The main target of the EUROATOM FP7 project “Fuel Qualification test for SCWR” is to make significant progress towards the design, analysis and licensing of a fuel assembly cooled with supercritical water in a research reactor. The program of dedicated WP4 - Pre-qualification was focused on evaluation of General Corrosion resistance of three pre-selected austenitic stainless steels 08Cr18Ni10Ti, AISI 347H and AISI 316L, which should be pre-qualified for application as a cladding material for fuel qualification tests in supercritical water. Therefore, the experiments in support of WP4 concentrated on 2000 h Corrosion exposures in 25 MPa SCW at two different temperatures 550 and 500°C dosed with both 150 and 2000 ppb of dissolved oxygen content. Moreover, water chemistry effect was investigated by conducting tests in 550°C SCW with 1.5 ppm of dissolved hydrogen content. At first, Corrosion coupons were exposed for 600, 1400 and 2000 h in JRC IET, VTT and SJTU autoclaves connected to recirculation loop allowing continual water chemistry control during the test. Following examination of the exposed specimens consisted of weight change calculations and detailed macro and microscopic investigation of oxide layers using SEM and EDX. With respect to General Corrosion results, all tested steels showed sufficient Corrosion resistance in SCW conditions taking into account the conditions foreseen for future fuel qualification test in the research reactor in CVR Rez. When the results of weight change calculations were compared for all three materials, it was found out, that the Corrosion resistance increased in the following order: 316L