ABSTRACT The occurrence of Atmospheric chloride-Induced Stress Corrosion Cracking (AISCC) under w... more ABSTRACT The occurrence of Atmospheric chloride-Induced Stress Corrosion Cracking (AISCC) under wetted deposits of MgCl2 or sea-salt at 70°C has been investigated at various Relative Humidities (RH). The appearance of AISCC is a function of the environmental RH. At 33% RH (the deliquescence point of MgCl2), AISCC generated under MgCl2 or sea-salt deposits is of a similar appearance with regards to the number of cracks produced and average crack length. At 50% RH sea-salt seems to be more aggressive at least in terms of crack frequency. This observation may highlight the significance of carnallite (KMgCl3.6H2O) in promoting AISCC in types 304L and 316L stainless steels. The use of accelerated testing methods to validate apparent thresholds in chloride deposition density and other critical factors that influence the initiation and propagation of AISCC is briefly discussed.
Page 1. Pit Stability Criteria for Aluminum and Implications for the Mechanism of Tunneling Corro... more Page 1. Pit Stability Criteria for Aluminum and Implications for the Mechanism of Tunneling Corrosion Anthony Cook, Stuart Lyon and Nick Stevens Materials Performance Centre, University of Manchester Sackville Street, PO Box 88, Manchester M60 1QD, UK ...
In most metallic systems that are protected by organic coatings, the absolute performance depends... more In most metallic systems that are protected by organic coatings, the absolute performance depends not so much on the quality of the coating but more on the response of the coating to defects that are either initially present, or that arise in the course of service. Here we study inhibition at a controlled through-thickness defect in organic-coated galvanised steel thus
Materials and Corrosion-werkstoffe Und Korrosion, 1996
A solid - state potentiometric sensor, based on the well - tried principle of the thermodynamic c... more A solid - state potentiometric sensor, based on the well - tried principle of the thermodynamic concentration cell, has been constructed. The sensor uses a conventional bi-electrode design with an entry side and an exit side at which the hydrogen is detected. The sensor has been used for the quantitative determination of the hydrogen activity (equivalent H2 pressure) generated during cathodic protection. Thus, the background hydrogen pressure in uncharged steel is 10−17.7 (2 × 10−18 atm.) with a variation of about 20 times. During cathodic protection this value rises by large amounts. Thus, using a zinc anode, the equivalent hydrogen pressure rose by 1010.3 (to 4.4 × 10−8 atm.) in 3.5% NaCl and by 1016.9 (to 0.16 atm.) in artificial sea water, indicating the much larger amounts of hydrogen present in the latter case. This compares, for example, with literature data of 0.11 μA cm−2 and 0.60 μA cm−2 for hydrogen permeation at −1000 mV (SCE) in 3.5% NaCl and artificial sea water respectively. Hydrogen entry and exit was also considerably slowed in sea water. These differences are caused by local surface pH buffering and deposit formation.Messungen der Wasserstoffaktivität in Eisen während kathodischen Schutzes mit Hilfe einer potentiometrischen KonzentrationszelleBasierend auf dem bewährten Prinzip der thermodynamischen Konzentrationszelle wurde ein potentiometrischer Festkörpersensor entwickelt. Der Sensor hat einen konventionellen Zwei - Elektroden - Aufbau mit einer Eintritts - und einer Austrittsseite, an der der Wasserstoff bestimmt wird. Der Sensor wurde für die quantitative Ermittlung der Aktivität des Wasserstoffs (entsprechend einem H2-Druck), der während des kathodischen Schutzes erzeugt wird, eingesetzt. Das Grundniveau der Wasserstoffaktivität in nichtbeladenem Stahl liegt bei etwa 10−17,7 (2 × 10−18 atm). Während des kathodischen Schutzes steigt dieser Wert beträchtlich an. Bei Einsatz einer Zinkanode stieg der äquivalente Wasserstoffdruck um 1010,3 (auf 4,4 × 10−8 atm) in 3,5% NaCl und um 1016,9 (auf 0,16 atm) in künstlichem Meerwasser, d.h. im letzten Fall liegen erheblich größere Wasserstoffgehalte vor. Dies wird verglichen mit Literaturangaben von 0,11 μA/cm2 und 0,60 μA/cm2 für die Wasserstoffpermeation bei −1000 mV (SCE) in 3,5% NaCl bzw. in künstlichem Meerwasser. Der Wasserstoffeintritt und -austritt war in Meerwasser ebenfalls erheblich langsamer. Diese Unterschiede sind auf lokale pH - Pufferung an der Oberfläche sowie die Bildung von Ablagerungen zurückzuführen.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
... 6. Rasheeduzzafar, SE Hussain, and SS AlSaadoun, Cement and Concrete Research, 21, 777(1991).... more ... 6. Rasheeduzzafar, SE Hussain, and SS AlSaadoun, Cement and Concrete Research, 21, 777(1991). ... 22. SE Hussain, Rasheeduzzafar, and Ahmed S. AlGahtani, Cement and Concrete Research, 24, 8(1994). References. 1. HG Smolczkyk. In: (2nd Ed. ed.),Proc. 5th. ...
We analyze the thermodynamic characteristics and specific features of the course of reactions of ... more We analyze the thermodynamic characteristics and specific features of the course of reactions of oxometalate reduction on the aluminum surface and the properties of the final products (the specific electric resistance of oxides). The absence of a correlation between the ranged series of these parameters led to the necessity of using artificial intellect for modeling the processes of formation of conversion coatings. We obtained and visualized in 3D space the dependences of the corrosion resistance of D16 alloy on the oxometalate concentration, pH, the time of sealing, and test duration. Artificial neural networks based on multilayer perceptrons were used for predicting the corrosion resistance of conversion coatings.
In the present investigation, based on pore solution analyses, the mechanisms of Friedel&... more In the present investigation, based on pore solution analyses, the mechanisms of Friedel's salt formation and the related chemical processes taking place in mortar due to chloride binding are dealt with. Pore solutions from mortars containing NaCl and CaCl2 added during mixing were analyzed. Based on the results it is proposed that in the presence of NaCl the Friedel's salt
ABSTRACT The occurrence of Atmospheric chloride-Induced Stress Corrosion Cracking (AISCC) under w... more ABSTRACT The occurrence of Atmospheric chloride-Induced Stress Corrosion Cracking (AISCC) under wetted deposits of MgCl2 or sea-salt at 70°C has been investigated at various Relative Humidities (RH). The appearance of AISCC is a function of the environmental RH. At 33% RH (the deliquescence point of MgCl2), AISCC generated under MgCl2 or sea-salt deposits is of a similar appearance with regards to the number of cracks produced and average crack length. At 50% RH sea-salt seems to be more aggressive at least in terms of crack frequency. This observation may highlight the significance of carnallite (KMgCl3.6H2O) in promoting AISCC in types 304L and 316L stainless steels. The use of accelerated testing methods to validate apparent thresholds in chloride deposition density and other critical factors that influence the initiation and propagation of AISCC is briefly discussed.
Page 1. Pit Stability Criteria for Aluminum and Implications for the Mechanism of Tunneling Corro... more Page 1. Pit Stability Criteria for Aluminum and Implications for the Mechanism of Tunneling Corrosion Anthony Cook, Stuart Lyon and Nick Stevens Materials Performance Centre, University of Manchester Sackville Street, PO Box 88, Manchester M60 1QD, UK ...
In most metallic systems that are protected by organic coatings, the absolute performance depends... more In most metallic systems that are protected by organic coatings, the absolute performance depends not so much on the quality of the coating but more on the response of the coating to defects that are either initially present, or that arise in the course of service. Here we study inhibition at a controlled through-thickness defect in organic-coated galvanised steel thus
Materials and Corrosion-werkstoffe Und Korrosion, 1996
A solid - state potentiometric sensor, based on the well - tried principle of the thermodynamic c... more A solid - state potentiometric sensor, based on the well - tried principle of the thermodynamic concentration cell, has been constructed. The sensor uses a conventional bi-electrode design with an entry side and an exit side at which the hydrogen is detected. The sensor has been used for the quantitative determination of the hydrogen activity (equivalent H2 pressure) generated during cathodic protection. Thus, the background hydrogen pressure in uncharged steel is 10−17.7 (2 × 10−18 atm.) with a variation of about 20 times. During cathodic protection this value rises by large amounts. Thus, using a zinc anode, the equivalent hydrogen pressure rose by 1010.3 (to 4.4 × 10−8 atm.) in 3.5% NaCl and by 1016.9 (to 0.16 atm.) in artificial sea water, indicating the much larger amounts of hydrogen present in the latter case. This compares, for example, with literature data of 0.11 μA cm−2 and 0.60 μA cm−2 for hydrogen permeation at −1000 mV (SCE) in 3.5% NaCl and artificial sea water respectively. Hydrogen entry and exit was also considerably slowed in sea water. These differences are caused by local surface pH buffering and deposit formation.Messungen der Wasserstoffaktivität in Eisen während kathodischen Schutzes mit Hilfe einer potentiometrischen KonzentrationszelleBasierend auf dem bewährten Prinzip der thermodynamischen Konzentrationszelle wurde ein potentiometrischer Festkörpersensor entwickelt. Der Sensor hat einen konventionellen Zwei - Elektroden - Aufbau mit einer Eintritts - und einer Austrittsseite, an der der Wasserstoff bestimmt wird. Der Sensor wurde für die quantitative Ermittlung der Aktivität des Wasserstoffs (entsprechend einem H2-Druck), der während des kathodischen Schutzes erzeugt wird, eingesetzt. Das Grundniveau der Wasserstoffaktivität in nichtbeladenem Stahl liegt bei etwa 10−17,7 (2 × 10−18 atm). Während des kathodischen Schutzes steigt dieser Wert beträchtlich an. Bei Einsatz einer Zinkanode stieg der äquivalente Wasserstoffdruck um 1010,3 (auf 4,4 × 10−8 atm) in 3,5% NaCl und um 1016,9 (auf 0,16 atm) in künstlichem Meerwasser, d.h. im letzten Fall liegen erheblich größere Wasserstoffgehalte vor. Dies wird verglichen mit Literaturangaben von 0,11 μA/cm2 und 0,60 μA/cm2 für die Wasserstoffpermeation bei −1000 mV (SCE) in 3,5% NaCl bzw. in künstlichem Meerwasser. Der Wasserstoffeintritt und -austritt war in Meerwasser ebenfalls erheblich langsamer. Diese Unterschiede sind auf lokale pH - Pufferung an der Oberfläche sowie die Bildung von Ablagerungen zurückzuführen.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
... 6. Rasheeduzzafar, SE Hussain, and SS AlSaadoun, Cement and Concrete Research, 21, 777(1991).... more ... 6. Rasheeduzzafar, SE Hussain, and SS AlSaadoun, Cement and Concrete Research, 21, 777(1991). ... 22. SE Hussain, Rasheeduzzafar, and Ahmed S. AlGahtani, Cement and Concrete Research, 24, 8(1994). References. 1. HG Smolczkyk. In: (2nd Ed. ed.),Proc. 5th. ...
We analyze the thermodynamic characteristics and specific features of the course of reactions of ... more We analyze the thermodynamic characteristics and specific features of the course of reactions of oxometalate reduction on the aluminum surface and the properties of the final products (the specific electric resistance of oxides). The absence of a correlation between the ranged series of these parameters led to the necessity of using artificial intellect for modeling the processes of formation of conversion coatings. We obtained and visualized in 3D space the dependences of the corrosion resistance of D16 alloy on the oxometalate concentration, pH, the time of sealing, and test duration. Artificial neural networks based on multilayer perceptrons were used for predicting the corrosion resistance of conversion coatings.
In the present investigation, based on pore solution analyses, the mechanisms of Friedel&... more In the present investigation, based on pore solution analyses, the mechanisms of Friedel's salt formation and the related chemical processes taking place in mortar due to chloride binding are dealt with. Pore solutions from mortars containing NaCl and CaCl2 added during mixing were analyzed. Based on the results it is proposed that in the presence of NaCl the Friedel's salt
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