Stress corrosion cracking （SCC） of X70 pipeline steel in simulated solution of the acidic soil in Yingtan in China was investigated using slow strain rate test （SSRT）, SEM and potentiodynamic polarization techniqu...Stress corrosion cracking （SCC） of X70 pipeline steel in simulated solution of the acidic soil in Yingtan in China was investigated using slow strain rate test （SSRT）, SEM and potentiodynamic polarization technique. Experiment results indicate that X70 steel is highly susceptible to SCC as applied potential reduces, which is manifested in loss of toughness and brittle fracture. Constaat polarization current can detect the occurrence of SCC. The lower the polarization current is the sooner stress corrosion cracking occurs. The SCC mechanisms are different at varying potentials. When potential is higher than open circuit potential, anodic process controls SCC, whereas when potential is far lower than open circuit potential, cathodic process controls SCC, and between these two potential regions, a combined electrochemical process controls the SCC. Stress or strain has a synergistic effect with electrochemical reactions to accelerate the cathodic hydrogen evolution process, which makes the X70 pipeline steel to be more susceptible to SCC.展开更多
This study aims at providing systematically insights to clarify the impact of cathodic polarization on the stress corrosion cracking(SCC)behavior of 21 Cr2 NiMo steel.Slow-strain-rate tensile tests demonstrated that 2...This study aims at providing systematically insights to clarify the impact of cathodic polarization on the stress corrosion cracking(SCC)behavior of 21 Cr2 NiMo steel.Slow-strain-rate tensile tests demonstrated that 21 Cr2 NiMo steel is highly sensitive to hydrogen embrittlement at strong cathodic polarization.The lowest SCC susceptibility occurred at-775 mV vs.SCE,whereas the SCC susceptibility was remarkably higher at potentials below-950 mV vs.SCE.Scanning electron microscopy(SEM)and electron backscattered diffraction(EBSD)revealed that the cathodic potential decline caused a transition from transgranular to intergranular mode in the fracture path.The intergranular mode transformed from bainite boundaries separation to prior austenitic grain boundaries separation under stronger cathodic polarization.Furthermore,corrosion pits promoted the nucleation of SCC cracks.In conclusion,with the decrease in the applied potential,the SCC mechanism transformed from the combination of hydrogen embrittlement and anodic dissolution to typical hydrogen embrittlement.展开更多
21Cr2NiMo steel is widely used to stabilize offshore oil platforms;however,it suffers from stress-corrosion cracking(SCC).Herein,we studied the SCC behavior of 21Cr2NiMo steel in SO_(2)-polluted coastal atmospheres.El...21Cr2NiMo steel is widely used to stabilize offshore oil platforms;however,it suffers from stress-corrosion cracking(SCC).Herein,we studied the SCC behavior of 21Cr2NiMo steel in SO_(2)-polluted coastal atmospheres.Electrochemical tests revealed that the addition of SO_(2) increased the corrosion current.Rust characterization showed that SO_(2) addition densified the corrosion products and promoted pitting.Furthermore,slow strain rate tests demonstrated a high susceptibility to SCC in high SO_(2) contents.Fracture morphologies revealed that the stress-corrosion cracks initiated at corrosion pits and the crack propagation showed transgranular and intergranular cracking modes.In conclusion,SCC is mix-controlled by anodic dissolution and hydrogen embrittlement mechanisms.展开更多
With epoxy coal tar as the coating material, the electrochemical corrosion behavior of Q235 with different kinds of bulk coating holidays has been investigated with EIS （Electrochemical Impedance Spectroscopy） in a ...With epoxy coal tar as the coating material, the electrochemical corrosion behavior of Q235 with different kinds of bulk coating holidays has been investigated with EIS （Electrochemical Impedance Spectroscopy） in a 3.5vo1% NaCI aqueous solution. The area ratio of bulk coating holiday to total coating area of steel is 4.91%. The experimental results showed that at free corrosion potential, the corrosion of carbon steel with disbonded coating holiday is heavier than that with broken holiday and disbonded ＆ broken holiday with time; Moreover, the effectiveness of Cathodic Protection （CP） of carbon steel with broken holiday is better than that with disbonded holiday and disbonded ＆ broken holiday on CP potential -850 mV （vs CSE）. Further analysis indicated that the two main reasons for corrosion are electrolyte solution slowly penetrating the coating, and crevice corrosion at steel/coating interface near holidays. The ratio of impedance amplitude （Z） of different frequency to minimum frequency is defined as K value. The change rate of K with frequency is related to the type of coating holiday.展开更多
This study focuses on developing a novel multiphase stainless steel with enhanced ductility and an ultralow yield ratio achieved through solid-solution treatment.The steel exhibits remarkable mechanical properties:a t...This study focuses on developing a novel multiphase stainless steel with enhanced ductility and an ultralow yield ratio achieved through solid-solution treatment.The steel exhibits remarkable mechanical properties:a tensile strength of approximately 1114 MPa,an ultralow yield ratio of 0.36,exceptional uniform elongation of approximately 17.48%,and total elongation of approximately 21.73%.The remarkable ductility of the steel can be attributed to the transformation-induced plasticity(TRIP)effect observed in the retained austenite,while its exceptional strength results from the combined effects of TRIP and the martensite phase.展开更多
The relationship between the corrosion resistance and martensite structure of Ni-advanced dual-phase weathering steel was studied using transmission electron microscopy,scanning electron microscopy,electrochemical ana...The relationship between the corrosion resistance and martensite structure of Ni-advanced dual-phase weathering steel was studied using transmission electron microscopy,scanning electron microscopy,electrochemical analysis,and atomic force microscopy.The investigations indicate that the final microstructure of the dual-phase weathering steel was composed of a large amount of low-carbon lath martensite distributed in the ferrite matrix.The potential of the martensite phase is higher than that of ferrite,which acts as a microcathode.As the martensite volume fraction in the Ni-advanced dual-phase weathering steel increased,the corrosion rate increased owing to the greater galvanic couple formed between the ferrite and martensite from the increasing ratio of the cathode area to the anode area.In addition,this work provides a method to obtain advanced weathering steel with improved mechanical properties and corrosion resistance.展开更多
In this work, the impact of a wild-type nitrate-reducing Bacillus licheniformis strain on the corrosion behavior of X80 steel under anaerobic conditions was studied by electrochemical tests and biofilm characterizatio...In this work, the impact of a wild-type nitrate-reducing Bacillus licheniformis strain on the corrosion behavior of X80 steel under anaerobic conditions was studied by electrochemical tests and biofilm characterization. The bioelectrochemical, electrochemical, and chemical reactions between X80 steel and microorganisms were investigated comprehensively. The results show that B. licheniformis can accelerate the corrosion of X80 steel substrate in early immersing by two ways: biocatalytic cathodic nitrate reduction and acidification induced by bacterially-secreted acids. However, the corrosion rate of X80 steel decreased after immersing for ca. 1 week in B. licheniformis culture due to iron biomineralization. This work provides direct insights into the mechanism of microbiologically influenced corrosion of carbon steel by the nitrate-reducing bacterium.展开更多
In the past decade, the sudden rise of high-entropy alloys(HEAs) has become a research hotspot in the domain of metal materials. HEAs break through the design concept of traditional single-principal element alloys, an...In the past decade, the sudden rise of high-entropy alloys(HEAs) has become a research hotspot in the domain of metal materials. HEAs break through the design concept of traditional single-principal element alloys, and the four core effects, especially the high entropy and cocktail effects, make HEAs exhibit much better corrosion resistance than traditional corrosion-resistant metal materials, e.g., stainless steels, copper-nickel alloys, and high-nickel alloys. Currently, the corrosion resistance of HEAs causes great concern in the field of corrosion research. This article reviews the corrosion behavior and mechanism of HEAs in various aqueous solutions, revealing the correlation among the composition, microstructure and corrosion resistance of HEAs, and elaborates the influence of heat treatment, anodizing treatment and preparation methods on the corrosion behavior of HEAs. This knowledge will benefit the on-demand design of corrosion-resistant HEAs, which is an important trend of future development. Finally, perspectives regarding the corrosion research of HEAs are outlined to guide future studies.展开更多
The effect of Mo content on the microstructure revolution and corrosion behavior of cast FeCoCrNiMox high-entropy alloys in chloride environments were investigated.Results indicate that FeCoCrNi and FeCoCrNiMo0.1 allo...The effect of Mo content on the microstructure revolution and corrosion behavior of cast FeCoCrNiMox high-entropy alloys in chloride environments were investigated.Results indicate that FeCoCrNi and FeCoCrNiMo0.1 alloys are in single FCC solid solution.The precipitates form in FeCoCrNiMo0.3 and increase in FeCoCrNiMo0.6 alloys.Pitting occurs on FeCoCrNi and FeCoCrNiMo0.1 alloys while FeCoCrNiMo0.3 and FeCoCrNiMo0.6 alloys suffer from preferential localized corrosion at the regions depleted in Cr and Mo.The higher Cr2O3/Cr(OH)3 ratio and the incorporation of Mo oxides make the passive film more protective and the corrosion resistance of the FeCoCrNiMo0.1 alloy is thus enhanced.The correlation between microstructure and corrosion behavior and the corresponding corrosion mechanism were clarified.展开更多
In this work,the beneficial effect of Sn addition on the corrosion resistance mechanism of Cr-Mo low alloy steel was studied.Results demonstrated that Sn improves the corrosion resistance of the steel matrix mainly by...In this work,the beneficial effect of Sn addition on the corrosion resistance mechanism of Cr-Mo low alloy steel was studied.Results demonstrated that Sn improves the corrosion resistance of the steel matrix mainly by influencing the microstructural transformation.Sn addition and the synergistic effect of Sn,Cr,and Mo promote the formation of α-FeOOH,SnO_(2),SnO,Cr(OH)_(3),and molybdates,lead to the improved protection and stability of the rust layer.This synergistic effect also endows the inner rust layer with cation selectivity,preventing the further penetration of Cl-and inhibiting the localized corrosion of steel.展开更多
The effect of pH value on the stress corrosion cracking （SCC） of API XT0 pipeline steel in simulated acidic soil solutions was investigated by using slow strain rate test, electrochemical polarization curves, electr...The effect of pH value on the stress corrosion cracking （SCC） of API XT0 pipeline steel in simulated acidic soil solutions was investigated by using slow strain rate test, electrochemical polarization curves, electrochemical impedance spectroscopy, and scanning electron microscopy, pH plays an important role in the susceptibility and electrochemical mechanism of SCC. The pH higher than 5 has no significant effect on electrochemical processes. By contrast, the pH lower than 5 intensifies cathodic hydrogen evolution reactions, thus increasing the cathodic current and corrosion potential. Under different pH values, the SCC mechanism of XT0 pipeline steel varies among anodic dissolution （AD）, hydrogen embrittlement （HE）, and the combination of AD and HE （AD ＋ HE） with variations of applied potential. At -850 mVscE, the SCC mechanism is HE if pH is less than 4 or AD 4- HE if pH value is more positive.展开更多
The corrosion behavior of 304 stainless steel(SS)in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated.After 14 days of immersion,no obvious pitting pit was observed on the SS surface ...The corrosion behavior of 304 stainless steel(SS)in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated.After 14 days of immersion,no obvious pitting pit was observed on the SS surface in the sterile medium.By contrast,the SS exhibited serious pitting corrosion with the largest pit depth of 5.0μm in the inoculated medium after 14 days.The results of electrochemical tests showed that the barrier property of the passive film decreased faster in the inoculated medium.The X-ray photoelectron spectroscopy results indicated that the detrimental Fe2+and Cr6+increased in the passive film under the influence of archaea N.tibetense,which resulted in the accelerated deterioration of passive film and promoted the pitting corrosion.Combined with the energy starvation tests,the microbiologically influenced corrosion mechanism of 304 SS caused by halophilic archaea N.tibetense was discussed finally.展开更多
Soil resistivity is one of the key indicators of the corrosive classification assessment on metal materials in soil environment. This paper presents variance characters of various quantity of soil resistivity samples ...Soil resistivity is one of the key indicators of the corrosive classification assessment on metal materials in soil environment. This paper presents variance characters of various quantity of soil resistivity samples data based on the semi-variance function methods of Geo-statistical Analysis by analyzing the regional soil resistivity sampling data in Daqing area. Furthermore, the variance of the soil resistivity as well as entire soil circumstance due to different sampling amounts are also analyzed and compared by means of using the characteristic parameters of the semi-variance function. In addition, this work also studied the rational sampling quantities according to various measurement errors required and evaluated the local soil corrosivity on carbon steel based on the actual measuring data in this area.展开更多
Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO...Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO-66/MoSe_(2) composite was prepared using the solvothermal method.The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe_(2).X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite,which may have affected its photocatalytic performance.The composite is composed of ultra-thin flower-like MoSe_(2) that wrapped around cubic UiO-66,a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers.The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst’s ability to reduce Cr(VI)-containing wastewater under visible light irradiation.Rhodamine B was decolorized completely in 120 min,and most of the Cr(VI)was reduced within 150 min.The photochemical mechanism of the complex was studied in detail.The existence of Mo^(6+)and oxygen vacancies,in addition to the Z-type heterojunction promote the separation of electrons and holes,which enhances the photocatalytic effect.展开更多
基金supported by Chinese National Science and Technology Infrastructure Platforms Construction Project (No.2005DKA10400)Major Foundation in the Tenth Five-Year Development Plan of China (No.50499333-08)
文摘Stress corrosion cracking （SCC） of X70 pipeline steel in simulated solution of the acidic soil in Yingtan in China was investigated using slow strain rate test （SSRT）, SEM and potentiodynamic polarization technique. Experiment results indicate that X70 steel is highly susceptible to SCC as applied potential reduces, which is manifested in loss of toughness and brittle fracture. Constaat polarization current can detect the occurrence of SCC. The lower the polarization current is the sooner stress corrosion cracking occurs. The SCC mechanisms are different at varying potentials. When potential is higher than open circuit potential, anodic process controls SCC, whereas when potential is far lower than open circuit potential, cathodic process controls SCC, and between these two potential regions, a combined electrochemical process controls the SCC. Stress or strain has a synergistic effect with electrochemical reactions to accelerate the cathodic hydrogen evolution process, which makes the X70 pipeline steel to be more susceptible to SCC.
基金financially supported by the National Science and Technology Major Project,China(No.2017-Ⅶ0012-0109)。
文摘This study aims at providing systematically insights to clarify the impact of cathodic polarization on the stress corrosion cracking(SCC)behavior of 21 Cr2 NiMo steel.Slow-strain-rate tensile tests demonstrated that 21 Cr2 NiMo steel is highly sensitive to hydrogen embrittlement at strong cathodic polarization.The lowest SCC susceptibility occurred at-775 mV vs.SCE,whereas the SCC susceptibility was remarkably higher at potentials below-950 mV vs.SCE.Scanning electron microscopy(SEM)and electron backscattered diffraction(EBSD)revealed that the cathodic potential decline caused a transition from transgranular to intergranular mode in the fracture path.The intergranular mode transformed from bainite boundaries separation to prior austenitic grain boundaries separation under stronger cathodic polarization.Furthermore,corrosion pits promoted the nucleation of SCC cracks.In conclusion,with the decrease in the applied potential,the SCC mechanism transformed from the combination of hydrogen embrittlement and anodic dissolution to typical hydrogen embrittlement.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.FRF-MP-18-002)。
文摘21Cr2NiMo steel is widely used to stabilize offshore oil platforms;however,it suffers from stress-corrosion cracking(SCC).Herein,we studied the SCC behavior of 21Cr2NiMo steel in SO_(2)-polluted coastal atmospheres.Electrochemical tests revealed that the addition of SO_(2) increased the corrosion current.Rust characterization showed that SO_(2) addition densified the corrosion products and promoted pitting.Furthermore,slow strain rate tests demonstrated a high susceptibility to SCC in high SO_(2) contents.Fracture morphologies revealed that the stress-corrosion cracks initiated at corrosion pits and the crack propagation showed transgranular and intergranular cracking modes.In conclusion,SCC is mix-controlled by anodic dissolution and hydrogen embrittlement mechanisms.
基金financially supported by the National Nature Science foundation of China (No.50301003 and 50461004)
文摘With epoxy coal tar as the coating material, the electrochemical corrosion behavior of Q235 with different kinds of bulk coating holidays has been investigated with EIS （Electrochemical Impedance Spectroscopy） in a 3.5vo1% NaCI aqueous solution. The area ratio of bulk coating holiday to total coating area of steel is 4.91%. The experimental results showed that at free corrosion potential, the corrosion of carbon steel with disbonded coating holiday is heavier than that with broken holiday and disbonded ＆ broken holiday with time; Moreover, the effectiveness of Cathodic Protection （CP） of carbon steel with broken holiday is better than that with disbonded holiday and disbonded ＆ broken holiday on CP potential -850 mV （vs CSE）. Further analysis indicated that the two main reasons for corrosion are electrolyte solution slowly penetrating the coating, and crevice corrosion at steel/coating interface near holidays. The ratio of impedance amplitude （Z） of different frequency to minimum frequency is defined as K value. The change rate of K with frequency is related to the type of coating holiday.
基金financially supported by the National Science and Technology Resources Investigation Program of China(Grant No.2021FY100604).
文摘This study focuses on developing a novel multiphase stainless steel with enhanced ductility and an ultralow yield ratio achieved through solid-solution treatment.The steel exhibits remarkable mechanical properties:a tensile strength of approximately 1114 MPa,an ultralow yield ratio of 0.36,exceptional uniform elongation of approximately 17.48%,and total elongation of approximately 21.73%.The remarkable ductility of the steel can be attributed to the transformation-induced plasticity(TRIP)effect observed in the retained austenite,while its exceptional strength results from the combined effects of TRIP and the martensite phase.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0300604)the National Natural Science Foundation of China(No.51671028)。
文摘The relationship between the corrosion resistance and martensite structure of Ni-advanced dual-phase weathering steel was studied using transmission electron microscopy,scanning electron microscopy,electrochemical analysis,and atomic force microscopy.The investigations indicate that the final microstructure of the dual-phase weathering steel was composed of a large amount of low-carbon lath martensite distributed in the ferrite matrix.The potential of the martensite phase is higher than that of ferrite,which acts as a microcathode.As the martensite volume fraction in the Ni-advanced dual-phase weathering steel increased,the corrosion rate increased owing to the greater galvanic couple formed between the ferrite and martensite from the increasing ratio of the cathode area to the anode area.In addition,this work provides a method to obtain advanced weathering steel with improved mechanical properties and corrosion resistance.
基金financially supported by the National Natural Science Foundation of China (No. 51871026)the National Key R&D Program of China (No. 2017YFF0210404)。
文摘In this work, the impact of a wild-type nitrate-reducing Bacillus licheniformis strain on the corrosion behavior of X80 steel under anaerobic conditions was studied by electrochemical tests and biofilm characterization. The bioelectrochemical, electrochemical, and chemical reactions between X80 steel and microorganisms were investigated comprehensively. The results show that B. licheniformis can accelerate the corrosion of X80 steel substrate in early immersing by two ways: biocatalytic cathodic nitrate reduction and acidification induced by bacterially-secreted acids. However, the corrosion rate of X80 steel decreased after immersing for ca. 1 week in B. licheniformis culture due to iron biomineralization. This work provides direct insights into the mechanism of microbiologically influenced corrosion of carbon steel by the nitrate-reducing bacterium.
基金the financial support from the National Key Research and Development Program of China(No.2017YFB0702100)the National Natural Science Foundation of China(No.52071014)。
文摘In the past decade, the sudden rise of high-entropy alloys(HEAs) has become a research hotspot in the domain of metal materials. HEAs break through the design concept of traditional single-principal element alloys, and the four core effects, especially the high entropy and cocktail effects, make HEAs exhibit much better corrosion resistance than traditional corrosion-resistant metal materials, e.g., stainless steels, copper-nickel alloys, and high-nickel alloys. Currently, the corrosion resistance of HEAs causes great concern in the field of corrosion research. This article reviews the corrosion behavior and mechanism of HEAs in various aqueous solutions, revealing the correlation among the composition, microstructure and corrosion resistance of HEAs, and elaborates the influence of heat treatment, anodizing treatment and preparation methods on the corrosion behavior of HEAs. This knowledge will benefit the on-demand design of corrosion-resistant HEAs, which is an important trend of future development. Finally, perspectives regarding the corrosion research of HEAs are outlined to guide future studies.
基金the National Material Environmental Corrosion infrastructurethe State Key Laboratory for Advanced Metals and Materials(No.2018Z-05)。
文摘The effect of Mo content on the microstructure revolution and corrosion behavior of cast FeCoCrNiMox high-entropy alloys in chloride environments were investigated.Results indicate that FeCoCrNi and FeCoCrNiMo0.1 alloys are in single FCC solid solution.The precipitates form in FeCoCrNiMo0.3 and increase in FeCoCrNiMo0.6 alloys.Pitting occurs on FeCoCrNi and FeCoCrNiMo0.1 alloys while FeCoCrNiMo0.3 and FeCoCrNiMo0.6 alloys suffer from preferential localized corrosion at the regions depleted in Cr and Mo.The higher Cr2O3/Cr(OH)3 ratio and the incorporation of Mo oxides make the passive film more protective and the corrosion resistance of the FeCoCrNiMo0.1 alloy is thus enhanced.The correlation between microstructure and corrosion behavior and the corresponding corrosion mechanism were clarified.
基金This work was supported by National Key R&D Program of China(2017YFB0702100)the Fundamental Research Funds for the Central Universities(No.FRF-MP-18-002)。
文摘In this work,the beneficial effect of Sn addition on the corrosion resistance mechanism of Cr-Mo low alloy steel was studied.Results demonstrated that Sn improves the corrosion resistance of the steel matrix mainly by influencing the microstructural transformation.Sn addition and the synergistic effect of Sn,Cr,and Mo promote the formation of α-FeOOH,SnO_(2),SnO,Cr(OH)_(3),and molybdates,lead to the improved protection and stability of the rust layer.This synergistic effect also endows the inner rust layer with cation selectivity,preventing the further penetration of Cl-and inhibiting the localized corrosion of steel.
基金financially supported by the National Natural Science Foundation of China(Nos.50901041 and 51131001)the China Postdoctoral Science Foundation(No.20100480196)the Fundamental Research Funds for the Central Universities(No.FRF-TP-12-148A)
文摘The effect of pH value on the stress corrosion cracking （SCC） of API XT0 pipeline steel in simulated acidic soil solutions was investigated by using slow strain rate test, electrochemical polarization curves, electrochemical impedance spectroscopy, and scanning electron microscopy, pH plays an important role in the susceptibility and electrochemical mechanism of SCC. The pH higher than 5 has no significant effect on electrochemical processes. By contrast, the pH lower than 5 intensifies cathodic hydrogen evolution reactions, thus increasing the cathodic current and corrosion potential. Under different pH values, the SCC mechanism of XT0 pipeline steel varies among anodic dissolution （AD）, hydrogen embrittlement （HE）, and the combination of AD and HE （AD ＋ HE） with variations of applied potential. At -850 mVscE, the SCC mechanism is HE if pH is less than 4 or AD 4- HE if pH value is more positive.
基金the Beijing Nova Program(No.Z171100001117076)the National Natural Science Foundation of China(Nos.51871026,51771029)the National Environmental Corrosion Platform。
文摘The corrosion behavior of 304 stainless steel(SS)in the presence of aerobic halophilic archaea Natronorubrum tibetense was investigated.After 14 days of immersion,no obvious pitting pit was observed on the SS surface in the sterile medium.By contrast,the SS exhibited serious pitting corrosion with the largest pit depth of 5.0μm in the inoculated medium after 14 days.The results of electrochemical tests showed that the barrier property of the passive film decreased faster in the inoculated medium.The X-ray photoelectron spectroscopy results indicated that the detrimental Fe2+and Cr6+increased in the passive film under the influence of archaea N.tibetense,which resulted in the accelerated deterioration of passive film and promoted the pitting corrosion.Combined with the energy starvation tests,the microbiologically influenced corrosion mechanism of 304 SS caused by halophilic archaea N.tibetense was discussed finally.
基金support of the National Natural Science Foundation of China (No.50971016)support of the National R&D Infrastructure and Facility Development Program of China (2005DKA10400)
文摘Soil resistivity is one of the key indicators of the corrosive classification assessment on metal materials in soil environment. This paper presents variance characters of various quantity of soil resistivity samples data based on the semi-variance function methods of Geo-statistical Analysis by analyzing the regional soil resistivity sampling data in Daqing area. Furthermore, the variance of the soil resistivity as well as entire soil circumstance due to different sampling amounts are also analyzed and compared by means of using the characteristic parameters of the semi-variance function. In addition, this work also studied the rational sampling quantities according to various measurement errors required and evaluated the local soil corrosivity on carbon steel based on the actual measuring data in this area.
基金supported by the National Natural Science Foundation of China (Grants Nos.22076039,and 22176051)Natural Science Foundation of Henan Province (Grant No.222300420054)excellent Science and Technology Innovation Team of Henan Normal University (Grant No.2021TD03).
文摘Metal-organic frameworks are recognized as promising multifunctional materials,especially metal-organic framework-based photocatalysts,which are considered to be ideal photocatalytic materials.Herein,a new type of UiO-66/MoSe_(2) composite was prepared using the solvothermal method.The optimum composite was selected by adjusting the mass ratio of UiO-66 and MoSe_(2).X-ray diffraction analysis showed that the mass ratio influenced the crystal plane exposure rate of the composite,which may have affected its photocatalytic performance.The composite is composed of ultra-thin flower-like MoSe_(2) that wrapped around cubic UiO-66,a structure that increases the abundance of active sites for reactions and is more conducive to the separation of carriers.The photocatalytic properties of the composite were evaluated by measuring the degradation rate of Rhodamine B and the catalyst’s ability to reduce Cr(VI)-containing wastewater under visible light irradiation.Rhodamine B was decolorized completely in 120 min,and most of the Cr(VI)was reduced within 150 min.The photochemical mechanism of the complex was studied in detail.The existence of Mo^(6+)and oxygen vacancies,in addition to the Z-type heterojunction promote the separation of electrons and holes,which enhances the photocatalytic effect.
