Documents disponibles écrits par cet auteur

Acidic/caustic alternating corrosion on carbon steel pipes in heat exchanger of ethylene plant / Y. Gong in Materials and corrosion, Vol. 62 N° 10 (Octobre 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 10 (Octobre 2011) . - pp. 967–978 Titre : Acidic/caustic alternating corrosion on carbon steel pipes in heat exchanger of ethylene plant Type de document : texte imprimé Auteurs : Y. Gong, Auteur ; C. Yang, Auteur ; C. Yao, Auteur Année de publication : 2012 Article en page(s) : pp. 967–978 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Acidic/caustic  alternating  corrosion  Carbon  steel  pipes  Caustic  embrittlement  Heat  exchanger  Pitting Résumé : Caustic embrittlement, a kind of stress corrosion cracking (SCC), is always encountered on materials under stresses amid caustic environment. Acidic corrosion is another familiar degradation on materials contacting acidic media. However, it has been seldom studied what effect would be resulted in on materials that are exposed to an acidic/caustic alternating environment. In this paper, failure events were discovered on the carbon steel pipes under such an alternating service condition due to frequent sharp fluctuations of the heat medium's (process water) pH values in a heat exchanger. What is more, even chloride ions and sulfur element were detected, i.e., pitting corrosion was involved as well. In order to identify the causes of the failure, matrix materials of the pipes were examined, failure defects on pipe surfaces were investigated, particularly the process water was thoroughly inspected via a series of characterization methods. Based on the analysis results, a novel four-level mechanism from microscopic scale to macroscopic scale was tentatively proposed to explain such an acidic/caustic alternating corrosion. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005741/abstract [article] Acidic/caustic alternating corrosion on carbon steel pipes in heat exchanger of ethylene plant [texte imprimé] / Y. Gong, Auteur ; C. Yang, Auteur ; C. Yao, Auteur . - 2012 . - pp. 967–978. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 10 (Octobre 2011) . - pp. 967–978 Mots-clés : Acidic/caustic  alternating  corrosion  Carbon  steel  pipes  Caustic  embrittlement  Heat  exchanger  Pitting Résumé : Caustic embrittlement, a kind of stress corrosion cracking (SCC), is always encountered on materials under stresses amid caustic environment. Acidic corrosion is another familiar degradation on materials contacting acidic media. However, it has been seldom studied what effect would be resulted in on materials that are exposed to an acidic/caustic alternating environment. In this paper, failure events were discovered on the carbon steel pipes under such an alternating service condition due to frequent sharp fluctuations of the heat medium's (process water) pH values in a heat exchanger. What is more, even chloride ions and sulfur element were detected, i.e., pitting corrosion was involved as well. In order to identify the causes of the failure, matrix materials of the pipes were examined, failure defects on pipe surfaces were investigated, particularly the process water was thoroughly inspected via a series of characterization methods. Based on the analysis results, a novel four-level mechanism from microscopic scale to macroscopic scale was tentatively proposed to explain such an acidic/caustic alternating corrosion. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005741/abstract

Chemical composition of the fruit essential oil of phellodendron chinense (Rutaceae) from China and Its antifungal activity against plant pathogenic fungi / Y. Gong in The journal of essential oil research, Vol. 23 N° 1 (Janvier/Fevrier 2011) 

Public ISBD [article]  in The journal of essential oil research > Vol. 23 N° 1 (Janvier/Fevrier 2011) . - pp. 108 - 112 Titre : Chemical composition of the fruit essential oil of phellodendron chinense (Rutaceae) from China and Its antifungal activity against plant pathogenic fungi Type de document : texte imprimé Auteurs : Y. Gong, Auteur ; L. Zhou, Auteur ; X. Shi, Auteur Année de publication : 2011 Article en page(s) : pp. 108 - 112 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Phellodendron  chinense  Rutaceae  Essential  oil  composition  Myrcene  Antifungal  activity  Spore  germination  Plant  pathogenic  fungi Index. décimale : 646 Résumé : Essential oil of Phellodendron chinense fruit was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. Myrcene (70.7%), b-elemene (4.7%) and p-cymene (4.4%) were the major compounds of the 20 identified components. The antifungal activity of the oil, evaluated against fifteen plant pathogenic fungi, was determined by mycelial radial growth inhibition method. The values of the mean inhibitory concentration (IC50) against the tested fungi were at a range of 0.24–1.46 mg/mL. Furthermore, IC50 of the oil against spore germination of Magnaporthe oryzae was determined to be 2.60 mg/mL. These results indicated that P. chinense oil could be a potential source of antimicrobial ingredients for plant disease control. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.jeoronline.com/archive/detail/55 [article] Chemical composition of the fruit essential oil of phellodendron chinense (Rutaceae) from China and Its antifungal activity against plant pathogenic fungi [texte imprimé] / Y. Gong, Auteur ; L. Zhou, Auteur ; X. Shi, Auteur . - 2011 . - pp. 108 - 112. Génie Chimique Langues : Anglais (eng) in The journal of essential oil research > Vol. 23 N° 1 (Janvier/Fevrier 2011) . - pp. 108 - 112 Mots-clés : Phellodendron  chinense  Rutaceae  Essential  oil  composition  Myrcene  Antifungal  activity  Spore  germination  Plant  pathogenic  fungi Index. décimale : 646 Résumé : Essential oil of Phellodendron chinense fruit was obtained by hydrodistillation and analyzed by GC-FID and GC-MS. Myrcene (70.7%), b-elemene (4.7%) and p-cymene (4.4%) were the major compounds of the 20 identified components. The antifungal activity of the oil, evaluated against fifteen plant pathogenic fungi, was determined by mycelial radial growth inhibition method. The values of the mean inhibitory concentration (IC50) against the tested fungi were at a range of 0.24–1.46 mg/mL. Furthermore, IC50 of the oil against spore germination of Magnaporthe oryzae was determined to be 2.60 mg/mL. These results indicated that P. chinense oil could be a potential source of antimicrobial ingredients for plant disease control. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.jeoronline.com/archive/detail/55

Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant / Z.-G. Yang in Materials and corrosion, Vol. 63 N° 1 (Janvier 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 7–17 Titre : Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant : Part I: Electrochemical corrosion Type de document : texte imprimé Auteurs : Z.-G. Yang, Auteur ; Y. Gong, Auteur ; J.-Z. Yuan, Auteur Année de publication : 2012 Article en page(s) : pp. 7–17 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Electrochemical  corrosion  Erosion  Heat  exchanger  Hydrogen-assisted  corrosion  Seawater  Titanium  tube Résumé : Titanium tubes generally exhibit superior resistance against electrochemical corrosions amid seawater for their passive films TiO2. However, hydrogen-assisted corrosion (HAC) is actually the Achilles' heel to titanium materials when the temperature exceeds near 70 °C. In this event, severe degradations like quick thinning and leakage were frequently detected on a large number of titanium tubes exposed to natural seawater environment within heat exchangers in a nuclear power plant, which caused serious safety problems. This paper is the Part I of totally two parts conducted for the whole failure analysis study, mainly focusing on electrochemical aspect of failure causes and their behaviors. By means of over ten kinds of characterization methods, the analysis results identified that the HAC induced by the interaction effects between galvanic corrosion and crevice corrosion led to local bulges of the inner walls of some titanium tubes, and then the bulges were quickly thinned and eventually ruptured under the eddy erosion from the seawater containing sediment particles. Finally, relevant mechanisms were addressed in detail and prevention methods were proposed as well. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106189/abstract [article] Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant : Part I: Electrochemical corrosion [texte imprimé] / Z.-G. Yang, Auteur ; Y. Gong, Auteur ; J.-Z. Yuan, Auteur . - 2012 . - pp. 7–17. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 7–17 Mots-clés : Electrochemical  corrosion  Erosion  Heat  exchanger  Hydrogen-assisted  corrosion  Seawater  Titanium  tube Résumé : Titanium tubes generally exhibit superior resistance against electrochemical corrosions amid seawater for their passive films TiO2. However, hydrogen-assisted corrosion (HAC) is actually the Achilles' heel to titanium materials when the temperature exceeds near 70 °C. In this event, severe degradations like quick thinning and leakage were frequently detected on a large number of titanium tubes exposed to natural seawater environment within heat exchangers in a nuclear power plant, which caused serious safety problems. This paper is the Part I of totally two parts conducted for the whole failure analysis study, mainly focusing on electrochemical aspect of failure causes and their behaviors. By means of over ten kinds of characterization methods, the analysis results identified that the HAC induced by the interaction effects between galvanic corrosion and crevice corrosion led to local bulges of the inner walls of some titanium tubes, and then the bulges were quickly thinned and eventually ruptured under the eddy erosion from the seawater containing sediment particles. Finally, relevant mechanisms were addressed in detail and prevention methods were proposed as well. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106189/abstract

Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant / Y. Gong in Materials and corrosion, Vol. 63 N° 1 (Janvier 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 18–28 Titre : Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant : Part II: Mechanical degradation Type de document : texte imprimé Auteurs : Y. Gong, Auteur ; Z.-G. Yang, Auteur ; J.-Z. Yuan, Auteur Année de publication : 2012 Article en page(s) : pp. 18–28 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Clogging  Erosion  Heat  exchanger  Recirculating  cooling  water  Seawater  Titanium  tube Résumé : Serious failure incidents like clogging, quick thinning, and leakage frequently occurred on lots of titanium tubes of heat exchangers in a nuclear power plant in China. In the Part I of the whole failure analysis study with totally two parts, factors mainly involving three kinds of electrochemical corrosions were investigated, including galvanic corrosion, crevice corrosion, and hydrogen-assisted corrosion. In the current Part II, through microscopically analyzing the ruptures on the leaked tubes by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), another four causes dominantly lying in the aspect of mechanical degradation were determined – clogging, erosion, mechanical damaging, and fretting. Among them, the erosion effect was the primary one, thus the stresses it exerted on the tube wall were also supplementarily evaluated by finite element method (FEM). Based on the analysis results, the different degradation extents and morphologies by erosion on the tubes when they were clogged by different substances such as seashell, rubber debris, and sediments were compared, and relevant mechanisms were discussed. Finally, countermeasures were put forward as well. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106190/abstract [article] Failure analysis of leakage on titanium tubes within heat exchangers in a nuclear power plant : Part II: Mechanical degradation [texte imprimé] / Y. Gong, Auteur ; Z.-G. Yang, Auteur ; J.-Z. Yuan, Auteur . - 2012 . - pp. 18–28. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 18–28 Mots-clés : Clogging  Erosion  Heat  exchanger  Recirculating  cooling  water  Seawater  Titanium  tube Résumé : Serious failure incidents like clogging, quick thinning, and leakage frequently occurred on lots of titanium tubes of heat exchangers in a nuclear power plant in China. In the Part I of the whole failure analysis study with totally two parts, factors mainly involving three kinds of electrochemical corrosions were investigated, including galvanic corrosion, crevice corrosion, and hydrogen-assisted corrosion. In the current Part II, through microscopically analyzing the ruptures on the leaked tubes by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS), another four causes dominantly lying in the aspect of mechanical degradation were determined – clogging, erosion, mechanical damaging, and fretting. Among them, the erosion effect was the primary one, thus the stresses it exerted on the tube wall were also supplementarily evaluated by finite element method (FEM). Based on the analysis results, the different degradation extents and morphologies by erosion on the tubes when they were clogged by different substances such as seashell, rubber debris, and sediments were compared, and relevant mechanisms were discussed. Finally, countermeasures were put forward as well. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106190/abstract