The effect of Al content(0.035 wt%,0.5 wt%,1 wt%,and 2 wt%)on the composition change of steel and slag as well as inclusion transformation of high manganese steel after it has equilibrated with Ca O-Si O_(2)-Al_(2)O_(...The effect of Al content(0.035 wt%,0.5 wt%,1 wt%,and 2 wt%)on the composition change of steel and slag as well as inclusion transformation of high manganese steel after it has equilibrated with Ca O-Si O_(2)-Al_(2)O_(3)-Mg O slag was studied using the method of slag/steel reaction.The experimental results showed that as the initial content of Al increased from 0.035 wt%to 2 wt%,Al gradually replaced Mn to react with Si O_(2)in slag to avoid the loss of Mn due to the reaction;this process caused both Al_(2)O_(3)in slag and Si in steel to increase while Si O_(2)and Mn O in slag to reduce.In addition,the type of inclusions also evolved as the initial Al content increased.The evolution route of inclusions was Mn O→Mn O-Al_(2)O_(3)-Mg O→Mg O→Mn O-Ca O-Al_(2)O_(3)-Mg O and Mn O-Ca O-Mg O.The shape of inclusions evolved from spherical to irregular,became faceted,and finally transformed to spherical.The average size of inclusions presented a trend that was increasing first and then decreasing.The transformation mechanism of inclusions was explored.As the initial content of Al increased,Mg and Ca were reduced from top slag into molten steel in sequence,which consequently caused the transformation of inclusions.展开更多
The influence of AI content on the Mg-AI alloys corrosion performance during sodium chloride induced atmospheric corrosion has been studied. It was found that the corrosion rate of three Mg-AI alloys was accelerated w...The influence of AI content on the Mg-AI alloys corrosion performance during sodium chloride induced atmospheric corrosion has been studied. It was found that the corrosion rate of three Mg-AI alloys was accelerated with increasing AI content. The poor corrosion resistance was attributed to the galvanic coupling between the phase and eutectic phase or α phase and the formation of porous corrosion products.展开更多
The effect of Al content on the performance of the Pd–S2O82-/Zr O2–Al2O3solid superacid catalyst was studied using n-pentane isomerization as a probe reaction. The catalysts were also characterized by X-ray diffract...The effect of Al content on the performance of the Pd–S2O82-/Zr O2–Al2O3solid superacid catalyst was studied using n-pentane isomerization as a probe reaction. The catalysts were also characterized by X-ray diffraction(XRD), Fourier transform Infrared(FTIR), specific surface area measurements(BET), thermogravimetry–differential thermal analysis(TG–DTA), H2-temperature programmed reduction(TPR) and NH3temperature-programmed desorption(NH3-TPD). The Pd–S2O82-/Zr O2–Al2O3catalyst made from Al2O3 mass fraction of 2.5% exhibited the best performance and its catalytic activity increased by 44.0% compared with Pd–S2O82-/Zr O2. The isopentane yield reached64.3% at a temperature of 238 °C, a reaction pressure of 2.0 MPa, a space velocity of 1.0 h-1and a H2/n-pentane molar ratio of 4.0. No obvious catalyst deactivation was observed within 100 h.展开更多
The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments a...The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic simulation.The results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce addition.The formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content dependent.When the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable phase.As a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) inclusions.In addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their types.However,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.展开更多
The microstructure,extrusion texture and corrosion behavior of extruded dilute Mg–Al–Ca–Mn alloy with diferent Al contents were investigated.The corrosion rate of the alloy was more sensitive to the Fe impurities.T...The microstructure,extrusion texture and corrosion behavior of extruded dilute Mg–Al–Ca–Mn alloy with diferent Al contents were investigated.The corrosion rate of the alloy was more sensitive to the Fe impurities.The 1.2 wt%Al showed the lowest corrosion rate,which was mainly attributed to the weakening of the cathode efect caused by the increase of the Al and the decrease of the Fe in the precipitated phase.Refned grains,stronger basal surface texture and higher corrosion potential deriving from the higher Al content of the matrix also further enhanced the corrosion resistance of the matrix.展开更多
The composition,morphology,size,and number of inclusions in Fe-22Mn-xAl-0.7C(x=0.5%,5.2%,and 10.5%)lightweight steels after smelting and heat treatment experiments are characterized by scanning electron microscopy and...The composition,morphology,size,and number of inclusions in Fe-22Mn-xAl-0.7C(x=0.5%,5.2%,and 10.5%)lightweight steels after smelting and heat treatment experiments are characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy from both 2D and 3D perspectives.The inclusions are classified into eight categories according to chemistry and morphology.For the steel sample with a low Al content(0.5%),the inclusions are MnS,AlN-MnS,and Al_(2)O_(3)-MnS,among which Al_(2)O_(3)-MnS is the primary type.With the increase in Al content in the steel sample(to 5.2%),the populations of AlN and AlN-MnS inclusions of 1-3μm in diameter increase.A further increase in Al content(to 10.5%)leads to a significant decrease in the amount of AlN inclusions of 1-3μm in diameter,and an increase in the amount of AlN-MnS inclusions.The precipitation behavior during the phase transformation is also studied by FactSage 8.0 thermodynamic software,and a precipitation mechanism is proposed based on the calculation results.During the heat treatment,AlN inclusions re-precipitate out,due to the interactions between Al and dissolved N in the steel matrix.However,AlN inclusions cannot grow large because of unfavorable kinetic conditions.The re-precipitation phenomenon of AlN is predominant under low Al and high N conditions but not at high Al cases.展开更多
基金financially supported by the Ministry of Industry and Information Technology of China(No.TC180A6MR)China Scholarship Council and the National Natural Science Foundation of China(No.51404020)。
文摘The effect of Al content(0.035 wt%,0.5 wt%,1 wt%,and 2 wt%)on the composition change of steel and slag as well as inclusion transformation of high manganese steel after it has equilibrated with Ca O-Si O_(2)-Al_(2)O_(3)-Mg O slag was studied using the method of slag/steel reaction.The experimental results showed that as the initial content of Al increased from 0.035 wt%to 2 wt%,Al gradually replaced Mn to react with Si O_(2)in slag to avoid the loss of Mn due to the reaction;this process caused both Al_(2)O_(3)in slag and Si in steel to increase while Si O_(2)and Mn O in slag to reduce.In addition,the type of inclusions also evolved as the initial Al content increased.The evolution route of inclusions was Mn O→Mn O-Al_(2)O_(3)-Mg O→Mg O→Mn O-Ca O-Al_(2)O_(3)-Mg O and Mn O-Ca O-Mg O.The shape of inclusions evolved from spherical to irregular,became faceted,and finally transformed to spherical.The average size of inclusions presented a trend that was increasing first and then decreasing.The transformation mechanism of inclusions was explored.As the initial content of Al increased,Mg and Ca were reduced from top slag into molten steel in sequence,which consequently caused the transformation of inclusions.
基金support by the National Natural ScienceFoundation of China (Grant No. 50571105) is acknowl-edged.
文摘The influence of AI content on the Mg-AI alloys corrosion performance during sodium chloride induced atmospheric corrosion has been studied. It was found that the corrosion rate of three Mg-AI alloys was accelerated with increasing AI content. The poor corrosion resistance was attributed to the galvanic coupling between the phase and eutectic phase or α phase and the formation of porous corrosion products.
基金Supported by the Technology Risk Innovation Foundation of China National Petroleum Corporation(07-06D-01-04-03-02)
文摘The effect of Al content on the performance of the Pd–S2O82-/Zr O2–Al2O3solid superacid catalyst was studied using n-pentane isomerization as a probe reaction. The catalysts were also characterized by X-ray diffraction(XRD), Fourier transform Infrared(FTIR), specific surface area measurements(BET), thermogravimetry–differential thermal analysis(TG–DTA), H2-temperature programmed reduction(TPR) and NH3temperature-programmed desorption(NH3-TPD). The Pd–S2O82-/Zr O2–Al2O3catalyst made from Al2O3 mass fraction of 2.5% exhibited the best performance and its catalytic activity increased by 44.0% compared with Pd–S2O82-/Zr O2. The isopentane yield reached64.3% at a temperature of 238 °C, a reaction pressure of 2.0 MPa, a space velocity of 1.0 h-1and a H2/n-pentane molar ratio of 4.0. No obvious catalyst deactivation was observed within 100 h.
基金This research was funded by National Natural Science Foundation of China(Grant No.51874033)Beijing Natural Science Foundation(Grant No.2182038)to Hai-yan Tang.
文摘The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic simulation.The results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce addition.The formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content dependent.When the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable phase.As a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) inclusions.In addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their types.However,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.
基金supported by the National Natural Science Foundation of China(No.51804130)the Key Research and Development Projects of Science and Technology Development Plan of Jilin Province(No.20180201054GX)the Graduate Innovation Fund of Jilin University(Nos.101832020CX241,101832020CX242).
文摘The microstructure,extrusion texture and corrosion behavior of extruded dilute Mg–Al–Ca–Mn alloy with diferent Al contents were investigated.The corrosion rate of the alloy was more sensitive to the Fe impurities.The 1.2 wt%Al showed the lowest corrosion rate,which was mainly attributed to the weakening of the cathode efect caused by the increase of the Al and the decrease of the Fe in the precipitated phase.Refned grains,stronger basal surface texture and higher corrosion potential deriving from the higher Al content of the matrix also further enhanced the corrosion resistance of the matrix.
基金This work was supported by the National Natural Science Foundation of China(Grant No.U20A20270).
文摘The composition,morphology,size,and number of inclusions in Fe-22Mn-xAl-0.7C(x=0.5%,5.2%,and 10.5%)lightweight steels after smelting and heat treatment experiments are characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy from both 2D and 3D perspectives.The inclusions are classified into eight categories according to chemistry and morphology.For the steel sample with a low Al content(0.5%),the inclusions are MnS,AlN-MnS,and Al_(2)O_(3)-MnS,among which Al_(2)O_(3)-MnS is the primary type.With the increase in Al content in the steel sample(to 5.2%),the populations of AlN and AlN-MnS inclusions of 1-3μm in diameter increase.A further increase in Al content(to 10.5%)leads to a significant decrease in the amount of AlN inclusions of 1-3μm in diameter,and an increase in the amount of AlN-MnS inclusions.The precipitation behavior during the phase transformation is also studied by FactSage 8.0 thermodynamic software,and a precipitation mechanism is proposed based on the calculation results.During the heat treatment,AlN inclusions re-precipitate out,due to the interactions between Al and dissolved N in the steel matrix.However,AlN inclusions cannot grow large because of unfavorable kinetic conditions.The re-precipitation phenomenon of AlN is predominant under low Al and high N conditions but not at high Al cases.
