Sulfide stress corrosion cracking (SSCC) behaviour of UNS G11180 steel in 5% NaCl solution with H2S was studied by slow strain rate tensile test (SSRT), SEM and electrochemical hydro gen permeation technique. The resu...Sulfide stress corrosion cracking (SSCC) behaviour of UNS G11180 steel in 5% NaCl solution with H2S was studied by slow strain rate tensile test (SSRT), SEM and electrochemical hydro gen permeation technique. The results reveal different cracking mechanism and H permeation current (IH) through UNS G11180 steel plate in different concentration of H2S solution. The susceptibility to SSCC of UNS G11180 Steel in 5% NaCl solution with H2S was evaluated by the permeation current(IH, μA), which depends on the concentration (c×10-6) of H2S by the equation:IH = 8.525 ×c0.7249. lt is proved that the electrochemical H permeation method is a practical way to assess the susceptibility to SSCC.展开更多
The effect of Cl- ion on the anodic iron dissolution in H2SO4 solutions containing H2S has been studied by using electrochemical polarization curve measurements. The competitive adsorption for Cl- and HS- ions at an a...The effect of Cl- ion on the anodic iron dissolution in H2SO4 solutions containing H2S has been studied by using electrochemical polarization curve measurements. The competitive adsorption for Cl- and HS- ions at an anodic potential has been calculated using the CNDO/2method. The results show that a ceftain concentration of the Cl- ion can be adsorbed steadily and inhibit the anodic reaction of iron catalyzed by HS-. However, when the Cl- ion reaches the saturation adsorption, it begins to promote the anodic reaction of iron due tO the increased negative charge of iron atoms.展开更多
With the aid of hydrogen permeating devices, the hydrogen permeation behaviors of X52 pipeline steel in NACE A solution with saturated H2S/CO2 were studied under the conditions of different ambient temperatures and pH...With the aid of hydrogen permeating devices, the hydrogen permeation behaviors of X52 pipeline steel in NACE A solution with saturated H2S/CO2 were studied under the conditions of different ambient temperatures and pH values, and the hydrogen permeation behaviors of X52 pipeline steel in weld seam zone were comparatively studied. The experimental results show that the hydrogen permeation coefficient value is directly proportional to the time required for reaching the saturation anode current and inversely proportional to the saturation anode current, and the hydrogen permeation coefficient is influenced by the corrosion scales; the temperature is directly proportional to the saturation anode current, and the hydrogen permeation coefficient is influenced by the temperature and corrosion scales, heat-affected zone and matrix zone in NACE A solution with saturated H2S/CO2 at normal temperature. The hydrogen permeation coefficient in weld seam zone is larger than that in heat-affected zone which is further larger than that in matrix zone.展开更多
Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)ca...Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.展开更多
文摘Sulfide stress corrosion cracking (SSCC) behaviour of UNS G11180 steel in 5% NaCl solution with H2S was studied by slow strain rate tensile test (SSRT), SEM and electrochemical hydro gen permeation technique. The results reveal different cracking mechanism and H permeation current (IH) through UNS G11180 steel plate in different concentration of H2S solution. The susceptibility to SSCC of UNS G11180 Steel in 5% NaCl solution with H2S was evaluated by the permeation current(IH, μA), which depends on the concentration (c×10-6) of H2S by the equation:IH = 8.525 ×c0.7249. lt is proved that the electrochemical H permeation method is a practical way to assess the susceptibility to SSCC.
文摘The effect of Cl- ion on the anodic iron dissolution in H2SO4 solutions containing H2S has been studied by using electrochemical polarization curve measurements. The competitive adsorption for Cl- and HS- ions at an anodic potential has been calculated using the CNDO/2method. The results show that a ceftain concentration of the Cl- ion can be adsorbed steadily and inhibit the anodic reaction of iron catalyzed by HS-. However, when the Cl- ion reaches the saturation adsorption, it begins to promote the anodic reaction of iron due tO the increased negative charge of iron atoms.
基金Funded by the Program for National Science Foundation for Distinguished Young Scholars (No.51125019)the National Natural Science Foundation of China (No.50904050)+2 种基金the Basic Projects of Sichuan Province of China(No.2011JY0106)Postdoctoral Science Foundation(No.20110490810)the Special Fund of China's Central Government for the Development of Local Colleges and Universities-the Project of National First-level Discipline in Oil and Gas Engineering
文摘With the aid of hydrogen permeating devices, the hydrogen permeation behaviors of X52 pipeline steel in NACE A solution with saturated H2S/CO2 were studied under the conditions of different ambient temperatures and pH values, and the hydrogen permeation behaviors of X52 pipeline steel in weld seam zone were comparatively studied. The experimental results show that the hydrogen permeation coefficient value is directly proportional to the time required for reaching the saturation anode current and inversely proportional to the saturation anode current, and the hydrogen permeation coefficient is influenced by the corrosion scales; the temperature is directly proportional to the saturation anode current, and the hydrogen permeation coefficient is influenced by the temperature and corrosion scales, heat-affected zone and matrix zone in NACE A solution with saturated H2S/CO2 at normal temperature. The hydrogen permeation coefficient in weld seam zone is larger than that in heat-affected zone which is further larger than that in matrix zone.
基金This work was carried out in the framework of PAPIIT-UNAM(IN-205823)project.
文摘Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.
