Zhang Z.-N.,Shanghai JiaoTong University |
Zhang X.-X.,State Nuclear Power Plant Service Company |
Li X.,Shanghai JiaoTong University |
Xie Y.-B.,Shanghai JiaoTong University
Mocaxue Xuebao/Tribology | Year: 2010
To better understand the piston secondary motion and tribological behaviors under different operating conditions, this paper presented a coupling model of the piston secondary dynamics and the fluid dynamic lubrication. Effects of the variation in the system inertia were considered in the model to study the transient behavior of piston secondary motion and piston skirt friction and friction loss. The variations of the engine speed, the piston secondary motion and piston skirt friction loss in the startup were simulated. The piston lateral motion and the piston skirt friction force in the startup and in the steady-state were analyzed. Results showed that the model can be applied to transient study the piston secondary motion and the piston skirt tirbological behavior.
Wang J.,CAS Shenyang Institute of Metal Research |
Li X.,CAS Shenyang Institute of Metal Research |
Li X.,State Nuclear Power Plant Service Co. |
Huang F.,CAS Shenyang Institute of Metal Research |
And 2 more authors.
Corrosion | Year: 2014
Corrosion behaviors of UNS N06690TT and N08800SN in simulated pressurized water reactor (PWR) primary water containing three concentrations of dissolved oxygen (DO) was studied by open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). These results have shown that DO in simulated PWR primary water produces a strong effect on Cr dissolution. At DO < 0.01 ppm, the electrochemical impedance of N06690TT at low frequency gradually increases and becomes larger than that of N08800SN, and N06690TT shows slightly better corrosion resistance than N08800SN. At DO ≥ 0.1 ppm, the electrochemical impedance of N06690TT at low frequency rapidly decreases and becomes lower than that of N08800SN with the increase of immersion time; N08800SN shows much better corrosion resistance than N06690TT. The spinel oxides NiFe2O4 or Fe 3O4 can form in the inner oxide layer on N08800SN due to relatively balanced ratio of Fe, Ni, which leads to the relatively stable corrosion resistance. Therefore, when DO in PWR primary water is 0.1 ppm or more, it is more suitable to choose N08800SN rather than N06690TT as the steam generator (SG) tubing materials. © 2014, NACE International.
Yu Z.-H.,State Nuclear Power Plant Service Company |
Yan H.-G.,Hunan University |
Yin X.-Y.,State Nuclear Power Plant Service Company |
Li Y.,State Nuclear Power Plant Service Company |
Yan G.-H.,State Nuclear Power Plant Service Company
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2012
The ZK60 magnesium alloy plates were welded by laser beam welding (LBW) and the microstructures in the partially melted zone (PMZ) of welded joints were investigated. For the as-cast alloy, the eutectoid mixtures along grain boundaries (GBs) in the PMZ are liquefied during welding, and their re-solidified materials present hypoeutectic characters, which lead to more severe segregation of the Zn element along GBs, and thus enhance the cracking tendency of the PMZ. The main reasons for liquation cracking of PMZ are described as that the absence of liquid at the terminal stage of solidification leads to the occurrence of shrinkage cavities in PMZ, from which liquation cracking initiates, and propagates along the weakened GBs under the tensile stress originating from solidification shrinkage and thermal contraction. Lower heat input can reduce the cracking tendency, and the plastic processing such as rolling also contributes to the mitigation of PMZ liquation cracking by reducing the size of eutectoid phases and changing their distribution in the base metal. © 2012 The Nonferrous Metals Society of China.
Hong J.,Fudan University |
Han D.,Fudan University |
Tan H.,Fudan University |
Tan H.,State Nuclear Power Plant Service Company |
And 3 more authors.
Corrosion Science | Year: 2013
Optimized double loop electrochemical potentiokinetic reactivation (DL-EPR) in combination with microstructure observation were successfully applied to study the sensitization of super duplex stainless steel UNS S32750 aged at 900°C for different duration to intergranular corrosion (IGC). The results indicated that the degree of sensitization increased gradually with the aging time increased from 10min to 4h due to the sigma phase precipitation, and Ir:Ia value reached the maximum value of 17.1%. However, further increasing aging time slightly decreased the sensitization due to the healing effect incurred by the diffusion of chromium from adjacent grains to chromium-depleted zone. © 2012 Elsevier Ltd.
Mao Y.,State Nuclear Power Plant Service Company |
Pei C.,University of Tokyo
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2014
A non-contact ultrasonic testing system using a pulsed laser for ultrasound generation and an EMAT for ultrasound detection were developed for the inner crack inspection. To avoid the laser-induced ablation damage on the specimen, thermo-elastic model was used to excite ultrasound, the EMAT probe was used to receive signals. The EMAT in plane and EMAT out of plane were used to study the transversed wave and longitudinal wave spreading in the half aluminum test block respectively. Finally, combining the shadow method, the test system was used to measure the crack on the back of the specimen, the crack depth and the actual depth are very close. It is shown that, in the thermoelastic mode, the laser excitation, the method for EMAT probe received signals are feasible in the inspection of cracks.
Fan Z.,State Nuclear Power Plant Service Company |
Xu H.,East China University of Science and Technology |
Li D.,East China University of Science and Technology |
Zhang L.,East China University of Science and Technology |
Liao L.,East China University of Science and Technology
Procedia Engineering | Year: 2012
A nanostructured surface layer was fabricated on 35# type carbon steel plate by using ultrasonic impact treatment (UIT) technique, The micro-structural features of the surface layer produced by UIT were characterized by optical microscopy (OM) observations, X-ray diffraction (XRD) and transmission electron microscopy (TEM), and hardness measurement was carried out in order to examine the hardness variation along the depth. Experimental results showed that the thickness of the plastic deformation layer varies from a few to about 100μm depending on the duration of UIT. Obvious grain refinement was observed and the gain size was about 10nm in the top surface layer. After UIT, the micro-hardness of the surface layer was enhanced significantly compared with that of the original sample, and the hardness increased when the duration of UIT increased. © 2011 Published by Elsevier Ltd.
Wang Z.,East China University of Science and Technology |
Wang Z.,State Nuclear Power Plant Service Company |
Wang F.,East China University of Science and Technology |
Cao J.,East China University of Science and Technology |
Wang J.,East China University of Science and Technology
Fuel Processing Technology | Year: 2010
Catalytic pyrolysis of pine wood was carried out in a fixed-bed reactor heated slowly from room temperature to 700 °C under a stream of purging argon to examine the effects of the physically mixed K2CO3 or Ca(OH)2 on the pyrolysis behaviors. K2CO3 demonstrated a stronger catalysis for decomposition of hemicellulose, cellulose and lignin constituents, leading to the reduced yield of liquid product in conjunction with the increased yields of gaseous and char products because of the promoted secondary reactions of liquid product. With the addition of 17.7 wt.% of K2CO3, none of saccharides, aldehydes and alcohols was formed and the formation of acids, furans and guaiacols was substantially reduced, whereas the yields of alkanes and phenols were increased. Potassium led to an increase in the cumulative yields of H2, CO2 and CO at 700 °C. Ca(OH)2 somewhat promoted the decomposition of cellulose and lignin constituents, and the effect of Ca(OH)2 on the yields of liquid and char was opposite to that of K2CO3. With the addition of 22.2 wt.% Ca(OH)2, some groups of liquid product such as acids and aldehydes disappeared completely and the yields of saccharides, furans and guaiacols were somewhat reduced, while the yield of alcohols was remarkably increased in contrast to the result of K 2CO3. The addition of Ca(OH)2 did not significantly change the total yield of gaseous product at 700 °C but enhanced the yield of H2. © 2009 Elsevier B.V. All rights reserved.
Zhong Z.,State Nuclear Power Plant Service Company |
Li J.,State Nuclear Power Plant Service Company
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2013
This paper briefly introduces the history, development, aims and roles, state of the art of Inspection Qualification in nuclear power industry in developed countries, such as US and UK. Then, the author reviewed the related works in China in past years and the state of art, the challenges and reflections of building China inspection qualification system. Furthermore, based on the actual situation in China, combined with the advantages and disadvantages of European Inspection Qualification system and ASME Performance Demonstration method, the author put forward some suggestions on organization, system and related technical basis to promote the establishment and development of inspection qualification system in China. It was obvious that the inspection qualifications have to be taken before nuclear power plant pre-service inspection or in-service inspection. The inspection qualification system shall be developed as soon as possible and it will improve nuclear power plants safety operation in China. Copyright © 2013 by ASME.
Zhimin Z.,State Nuclear Power Plant Service Company |
Jian M.,State Nuclear Power Plant Service Company |
Kai L.,State Nuclear Power Plant Service Company
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2013
This paper briefly introduces the weld cladding structure, its common defects during the manufacture and operation stage and its application in pressurized water reactor nuclear power plants. Some ultrasonic testing codes or standards for nuclear power plant pressure vessel or piping, such as ASME BPVC volume V & III & XI, Germany KTA 3201.3 and 3201.4 code, France RCC-M and RSE-M code, and Russia code of light water nuclear power plants were discussed. The difference of those codes and some feed backs have been analyzed and discussed. Furthermore, these works really benefit the compiling of NB/T 20003.2-2010, Non-destructive Testing for Mechanical Components in Nuclear Island of Nuclear Power Plants-Part 2: Ultrasonic Testing, as China building more and more nuclear power plants. It was concluded that we shall pay more attention to the inspection of cladding, not only at manufacture stage but in operation outage stage. One of important work is periodically updating the inspection standard revision. It was believed that improving the cladding defects inspection reliability and effectiveness is very important to the safety of nuclear power plants operation in China and in the world. Copyright © 2013 by ASME.
Wu X.,State Nuclear Power Plant Service Company |
Li Y.,State Nuclear Power Plant Service Company |
Zhong Z.,State Nuclear Power Plant Service Company
9th International Topical Meeting on Nuclear Plant Instrumentation, Control, and Human-Machine Interface Technologies, NPIC and HMIT 2015 | Year: 2015
State Nuclear Power Plant Service Company is conducting aging research on representative safety-related cable samples used in China nuclear power plant. The objectives of this study are to determine the suitability of these cables for extended life, beyond the 40-year design basis. Simultaneous thermal and radiation accelerated aging, which provides condition similar to that in nuclear power plants, were conducted. The results of mechanical measurements, including elongation at break and indenter modulus, were performed on simultaneous aging cable specimens at different acceleration factors were discussed. Properties of cables under certain simultaneous aging rate with different time were measured. Properties of cables under different simultaneous aging rate with same damage energy were compared. Some cables show different level of degradation rate during simultaneous aging at different acceleration factors. Of the parameters tested, elongation at break tends to show the most correlation with amount of aging for all insulation and jacket materials. Indenter modulus appears relative limited material application. For some cables, there are good correlations between the elongation at break and indenter modulus, which might provide hints for determination of the end point for the indenter modulus.