The corrosion and passive behavior of HP-13Cr stainless steel(HP-13Cr SS)in formate annulus protection fluid was investigated.HP-13Cr SS exhibited good passive behavior in clean formate annulus protection fluid,which ...The corrosion and passive behavior of HP-13Cr stainless steel(HP-13Cr SS)in formate annulus protection fluid was investigated.HP-13Cr SS exhibited good passive behavior in clean formate annulus protection fluid,which was attributed to a thinner and more dense passive film mainly composed of Cr_(2)O_(3).In the formation water solution,the passive film was composed of metastable Cr(OH)3,which was explained by the isoelectric point theory,resulting in the deterioration of the passive behavior of HP-13Cr SS.When the formation water penetrated the formate annulus protection fluid,a large number of loose FeCO_(3)particles formed in the corrosion scales,thus HP-13Cr SS suffered severe corrosion.Therefore,avoiding formation water penetrating the formate annulus protection fluid is conducive to improving the service life of HP-13Cr SS oil tubes in extremely aggressive environment.展开更多
The effect of solution pH,Cl;concentration and temperature on the electrochemical corrosion behavior of PH13-8Mo steel in acidic solution was investigated by using the electrochemical tests,scanning electron microscop...The effect of solution pH,Cl;concentration and temperature on the electrochemical corrosion behavior of PH13-8Mo steel in acidic solution was investigated by using the electrochemical tests,scanning electron microscopy and X-ray photoelectron spectroscopy.The PH13-8Mo martensitic precipitation hardened stainless steel is in the passivity state when the pH value is above 3.0,below which the anodic polarization curves of the steel are actively dissolved.The corrosion current density gradually decreases with increasing the solution pH and decreasing Cl;concentration and solution temperature.Pits are initiated on the sample surface in the presence of the Cl;and gradually developed into uniform corrosion with increasing the Cl;concentrations.Moreover,the corrosion is more serious with an increase in solution temperature.展开更多
The passivation of magnesium(Mg)-based alloys is an electrochemical behavior.The formation of a protective surface film results in passivation.The composition of this surface layer is influenced by the substrate alloy...The passivation of magnesium(Mg)-based alloys is an electrochemical behavior.The formation of a protective surface film results in passivation.The composition of this surface layer is influenced by the substrate alloy,which in turn affects the passive behavior.Recent studies have examined the composition of the surface film when Mg alloys undergo corrosion.Most of these studies have focused on the presence of Mg hydroxide(Mg(OH)_(2))and Mg O in the layer.However,a systematic examination of the impact of alloying elements on the stability of the passive layer is lacking.The essential question for developing a corrosion-resistant Mg-based alloy with passive protection is:which are the best and most efficient elements that can form a passive layer when alloyed with Mg?Passivity in a Mg alloy could be achieved by using a non-equilibrium technique to supersaturate the matrix phase with a high concentration of a strong passivating element.This review paper examines and explores the potential of creating a passive Mg-based alloy using metallurgical methods,like alloying and purification.Additionally,this paper explains key concepts about the passivity of Mg alloys and proposes possible methods to create a passive Mg alloy.展开更多
Four quanternary Zr-based bulk metallic glasses（BMGs）were selected,including the Zr_（46）Ti_2Cu_（45）Al_7,Zr_（61）Ti_2Cu_（25）Al_（12）,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）,due to t...Four quanternary Zr-based bulk metallic glasses（BMGs）were selected,including the Zr_（46）Ti_2Cu_（45）Al_7,Zr_（61）Ti_2Cu_（25）Al_（12）,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）,due to their robust glass-forming ability and containing a single species of late transition metal（LTM）in compositions.Their pitting resistances in 0.6 M Na Cl aqueous solution were investigated to examine the role of LTM elements in the alloys,with electrochemical measurements,surface morphology observation and x-ray photoelectron spectrometry analysis.It is shown that in comparision with two Cu-bearing BMGs,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）BMGs exhibited significantly superior resistance to pitting.Zr_（61）Ti_2Cu_（25）Al_（12）,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）BMGs manifested distinct passivation behaviour,because of the formation of surface passive film mainly comprising of Zr O_2,Ti O_2and Al_2O_3.However,no significant differences in the electrochemical resistive properties and thicknesses of passive films were found between Zr_（61）Ti_2Cu_（25）Al_（12）and Zr_（55）Ti_4Ni_（22）Al_（19）BMGs.Nevertheless,at the passive film/metal interface,copper enrichment took place in Zr_（61）Ti_2Cu_（25）Al_（12）,whereas the nickel was slightly deficient at the interface in Zr_（55）Ti_4Ni_（22）Al_（19）.During pitting propagation,selective dissolution of the zirconium,titanium and aluminum over the copper took place in Zr_（61）Ti_2Cu_（25）Al_（12）,but it was not the case in Zr_（55）Ti_4Ni_（22）Al_（19）.For the two Cu-bearing BMGs,reduction of passive base metal elements in composition resulted in local selective dissolution,even absence of the passivation.展开更多
基金supported by the Youth Program of the National Natural Science Foundation of China(No.52001061)the Young Elite Scientist Sponsorship Program Cast(No.YESS20200139)the Fundamental Research Funds for the Central Universities(No.N2202016).
文摘The corrosion and passive behavior of HP-13Cr stainless steel(HP-13Cr SS)in formate annulus protection fluid was investigated.HP-13Cr SS exhibited good passive behavior in clean formate annulus protection fluid,which was attributed to a thinner and more dense passive film mainly composed of Cr_(2)O_(3).In the formation water solution,the passive film was composed of metastable Cr(OH)3,which was explained by the isoelectric point theory,resulting in the deterioration of the passive behavior of HP-13Cr SS.When the formation water penetrated the formate annulus protection fluid,a large number of loose FeCO_(3)particles formed in the corrosion scales,thus HP-13Cr SS suffered severe corrosion.Therefore,avoiding formation water penetrating the formate annulus protection fluid is conducive to improving the service life of HP-13Cr SS oil tubes in extremely aggressive environment.
基金financially sponsored by the National Basic Research Program of China(2014CB643306)
文摘The effect of solution pH,Cl;concentration and temperature on the electrochemical corrosion behavior of PH13-8Mo steel in acidic solution was investigated by using the electrochemical tests,scanning electron microscopy and X-ray photoelectron spectroscopy.The PH13-8Mo martensitic precipitation hardened stainless steel is in the passivity state when the pH value is above 3.0,below which the anodic polarization curves of the steel are actively dissolved.The corrosion current density gradually decreases with increasing the solution pH and decreasing Cl;concentration and solution temperature.Pits are initiated on the sample surface in the presence of the Cl;and gradually developed into uniform corrosion with increasing the Cl;concentrations.Moreover,the corrosion is more serious with an increase in solution temperature.
文摘The passivation of magnesium(Mg)-based alloys is an electrochemical behavior.The formation of a protective surface film results in passivation.The composition of this surface layer is influenced by the substrate alloy,which in turn affects the passive behavior.Recent studies have examined the composition of the surface film when Mg alloys undergo corrosion.Most of these studies have focused on the presence of Mg hydroxide(Mg(OH)_(2))and Mg O in the layer.However,a systematic examination of the impact of alloying elements on the stability of the passive layer is lacking.The essential question for developing a corrosion-resistant Mg-based alloy with passive protection is:which are the best and most efficient elements that can form a passive layer when alloyed with Mg?Passivity in a Mg alloy could be achieved by using a non-equilibrium technique to supersaturate the matrix phase with a high concentration of a strong passivating element.This review paper examines and explores the potential of creating a passive Mg-based alloy using metallurgical methods,like alloying and purification.Additionally,this paper explains key concepts about the passivity of Mg alloys and proposes possible methods to create a passive Mg alloy.
基金supported by the National Natural Science Foundation of China under Grant No. 51571192
文摘Four quanternary Zr-based bulk metallic glasses（BMGs）were selected,including the Zr_（46）Ti_2Cu_（45）Al_7,Zr_（61）Ti_2Cu_（25）Al_（12）,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）,due to their robust glass-forming ability and containing a single species of late transition metal（LTM）in compositions.Their pitting resistances in 0.6 M Na Cl aqueous solution were investigated to examine the role of LTM elements in the alloys,with electrochemical measurements,surface morphology observation and x-ray photoelectron spectrometry analysis.It is shown that in comparision with two Cu-bearing BMGs,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）BMGs exhibited significantly superior resistance to pitting.Zr_（61）Ti_2Cu_（25）Al_（12）,Zr_（55）Ti_4Ni_（22）Al_（19）and Zr_（55）Ti_2Co_（28）Al_（15）BMGs manifested distinct passivation behaviour,because of the formation of surface passive film mainly comprising of Zr O_2,Ti O_2and Al_2O_3.However,no significant differences in the electrochemical resistive properties and thicknesses of passive films were found between Zr_（61）Ti_2Cu_（25）Al_（12）and Zr_（55）Ti_4Ni_（22）Al_（19）BMGs.Nevertheless,at the passive film/metal interface,copper enrichment took place in Zr_（61）Ti_2Cu_（25）Al_（12）,whereas the nickel was slightly deficient at the interface in Zr_（55）Ti_4Ni_（22）Al_（19）.During pitting propagation,selective dissolution of the zirconium,titanium and aluminum over the copper took place in Zr_（61）Ti_2Cu_（25）Al_（12）,but it was not the case in Zr_（55）Ti_4Ni_（22）Al_（19）.For the two Cu-bearing BMGs,reduction of passive base metal elements in composition resulted in local selective dissolution,even absence of the passivation.
