The insoluble aluminum content in steel samples has a significant influence on the quality of the steel. In this paper, laser-induced breakdown spectroscopy （LIBS） is used to analyze the insoluble aluminum content i...The insoluble aluminum content in steel samples has a significant influence on the quality of the steel. In this paper, laser-induced breakdown spectroscopy （LIBS） is used to analyze the insoluble aluminum content in steel samples using a scanning mode. The average intensity plus 2.5 standard deviations was iterated and the final iteration value was taken as the threshold that distinguishes soluble and insoluble aluminum, and thus total and soluble aluminum content calibration curves were generated. Using the relevant total and soluble aluminum content calibration curves, the total and soluble aluminum contents in steel samples could be determined. The insoluble aluminum content could be determined by subtracting the soluble aluminum content from the total aluminum content. The insoluble aluminum content of standard samples and process product samples were determined using the present mathematical model; the results agreed well with the certified reference values. This method could be used to rapidly characterize the insoluble aluminum content in steel samples.展开更多
As a key step in secondary refining, the deoxidation process in clean stainless steel production is widely researched by many scholars. In this study, vacuum oxygen decarburization（VOD） deoxidation refining in a 40-...As a key step in secondary refining, the deoxidation process in clean stainless steel production is widely researched by many scholars. In this study, vacuum oxygen decarburization（VOD） deoxidation refining in a 40-t electric arc furnace ＋ VOD ＋ ingot casting process was analyzed and optimized on the basis of Al deoxidation of stainless steel and thermodynamic equilibrium reactions between the slag and steel. Under good stirring conditions in VOD, the deoxidation reaction reaches equilibrium rapidly, and the oxygen activity in the bulk steel is controlled by the slag composition and Al content. A basicity of 3–5 and an Al content greater than 0.015wt% in the melt resulted in an oxygen content less than 0.0006wt%. In addition, the dissolved oxygen content decreased slightly when the Al content in the steel was greater than 0.02wt%. Because of the equilibrium of the Si–O reaction between the slag and steel, the activity of SiO2 will increase while the Si content increases; thus, the Si content should be lowered to enable the formation of a high-basicity slag. A high-basicity, low-Al2O3 slag and an increased Si content will reduce the Al consumption caused by SiO2 reduction.展开更多
Tea consumption has increased due to its beneficial effects. Results from a lab study on the effect of sucrose (5 g per cup, 150 mL) and/or ascorbic acid (2 mL per cup, 150 mL) on dissolved aluminum compounds during t...Tea consumption has increased due to its beneficial effects. Results from a lab study on the effect of sucrose (5 g per cup, 150 mL) and/or ascorbic acid (2 mL per cup, 150 mL) on dissolved aluminum compounds during the infusion of two commercial types of dry tea leaves (black, green) with boiling water (5, 15 min infusion time) are presented. Factors influencing the presence of dissolved aluminum in the infusions of both tea leaves were infusion time and sugar contents, as well as the interaction between ascorbic acid and sucrose (p < 0.05). Aluminum contents found after 15 min of infusion were 0.7 mg L–1 for black tea infusions added with sugar, and 0.69 mg L–1 for green tea added with both sugar and ascorbic acid. Both concentrations are higher than the level accepted in Mexico for drinking water (there is no act concerning tea infusions), that is 0.2 mg L–1.展开更多
The design of the active region structures,including the modifications of structures of the quantum barrier(QB)and electron blocking layer(EBL),in the deep ultraviolet(DUV)Al Ga N laser diode(LD)is investigated numeri...The design of the active region structures,including the modifications of structures of the quantum barrier(QB)and electron blocking layer(EBL),in the deep ultraviolet(DUV)Al Ga N laser diode(LD)is investigated numerically with the Crosslight software.The analyses focus on electron and hole injection efficiency,electron leakage,hole diffusion,and radiative recombination rate.Compared with the reference QB structure,the step-like QB structure provides high radiative recombination and maximum output power.Subsequently,a comparative study is conducted on the performance characteristics with four different EBLs.For the EBL with different Al mole fraction layers,the higher Al-content Al Ga N EBL layer is located closely to the active region,leading the electron current leakage to lower,the carrier injection efficiency to increase,and the radiative recombination rate to improve.展开更多
By making castings that pick up gas from moisture in red sand molds,the porosity generated at different cooling rates was discussed during solidification of hypereutectic Al-25%Si alloy without and with phosphorus add...By making castings that pick up gas from moisture in red sand molds,the porosity generated at different cooling rates was discussed during solidification of hypereutectic Al-25%Si alloy without and with phosphorus additions. The effect of phosphorus addition on hydrogen content in the melt was also studied. It was observed that the phosphorus addition made hydrogen content in alloy melts present a “see-saw' tendency.In addition to primary silicon refinement,the phosphorus promoted gas porosity formed not only in slowly cooled sections, but also in rapidly cooled sections. There was a small difference in density of full dense sample between P-refined and unrefined castings, with a larger density associated with phosphorous addition. The change of the surface tension seemed more reasonable to explain the mechanism of porosity behavior.展开更多
Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(...Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.展开更多
基金supported by National Key Scientific Instrument and Equipment Development Project,China(No.2012YQ20018208)
文摘The insoluble aluminum content in steel samples has a significant influence on the quality of the steel. In this paper, laser-induced breakdown spectroscopy （LIBS） is used to analyze the insoluble aluminum content in steel samples using a scanning mode. The average intensity plus 2.5 standard deviations was iterated and the final iteration value was taken as the threshold that distinguishes soluble and insoluble aluminum, and thus total and soluble aluminum content calibration curves were generated. Using the relevant total and soluble aluminum content calibration curves, the total and soluble aluminum contents in steel samples could be determined. The insoluble aluminum content could be determined by subtracting the soluble aluminum content from the total aluminum content. The insoluble aluminum content of standard samples and process product samples were determined using the present mathematical model; the results agreed well with the certified reference values. This method could be used to rapidly characterize the insoluble aluminum content in steel samples.
基金financially supported by the China Postdoctoral Science Foundation (Nos. 2015T80039 and 2014M560890)
文摘As a key step in secondary refining, the deoxidation process in clean stainless steel production is widely researched by many scholars. In this study, vacuum oxygen decarburization（VOD） deoxidation refining in a 40-t electric arc furnace ＋ VOD ＋ ingot casting process was analyzed and optimized on the basis of Al deoxidation of stainless steel and thermodynamic equilibrium reactions between the slag and steel. Under good stirring conditions in VOD, the deoxidation reaction reaches equilibrium rapidly, and the oxygen activity in the bulk steel is controlled by the slag composition and Al content. A basicity of 3–5 and an Al content greater than 0.015wt% in the melt resulted in an oxygen content less than 0.0006wt%. In addition, the dissolved oxygen content decreased slightly when the Al content in the steel was greater than 0.02wt%. Because of the equilibrium of the Si–O reaction between the slag and steel, the activity of SiO2 will increase while the Si content increases; thus, the Si content should be lowered to enable the formation of a high-basicity slag. A high-basicity, low-Al2O3 slag and an increased Si content will reduce the Al consumption caused by SiO2 reduction.
文摘Tea consumption has increased due to its beneficial effects. Results from a lab study on the effect of sucrose (5 g per cup, 150 mL) and/or ascorbic acid (2 mL per cup, 150 mL) on dissolved aluminum compounds during the infusion of two commercial types of dry tea leaves (black, green) with boiling water (5, 15 min infusion time) are presented. Factors influencing the presence of dissolved aluminum in the infusions of both tea leaves were infusion time and sugar contents, as well as the interaction between ascorbic acid and sucrose (p < 0.05). Aluminum contents found after 15 min of infusion were 0.7 mg L–1 for black tea infusions added with sugar, and 0.69 mg L–1 for green tea added with both sugar and ascorbic acid. Both concentrations are higher than the level accepted in Mexico for drinking water (there is no act concerning tea infusions), that is 0.2 mg L–1.
基金Project supported by the Special Project for Inter-government Collaboration of State Key Research and Development Program,China(Grant No.2016YFE0118400)the Key Project of Science and Technology of Henan Province,China(Grant No.172102410062)the National Natural Science Foundation of China and Henan Provincial Joint Fund Key Project(Grant No.U1604263)
文摘The design of the active region structures,including the modifications of structures of the quantum barrier(QB)and electron blocking layer(EBL),in the deep ultraviolet(DUV)Al Ga N laser diode(LD)is investigated numerically with the Crosslight software.The analyses focus on electron and hole injection efficiency,electron leakage,hole diffusion,and radiative recombination rate.Compared with the reference QB structure,the step-like QB structure provides high radiative recombination and maximum output power.Subsequently,a comparative study is conducted on the performance characteristics with four different EBLs.For the EBL with different Al mole fraction layers,the higher Al-content Al Ga N EBL layer is located closely to the active region,leading the electron current leakage to lower,the carrier injection efficiency to increase,and the radiative recombination rate to improve.
文摘By making castings that pick up gas from moisture in red sand molds,the porosity generated at different cooling rates was discussed during solidification of hypereutectic Al-25%Si alloy without and with phosphorus additions. The effect of phosphorus addition on hydrogen content in the melt was also studied. It was observed that the phosphorus addition made hydrogen content in alloy melts present a “see-saw' tendency.In addition to primary silicon refinement,the phosphorus promoted gas porosity formed not only in slowly cooled sections, but also in rapidly cooled sections. There was a small difference in density of full dense sample between P-refined and unrefined castings, with a larger density associated with phosphorous addition. The change of the surface tension seemed more reasonable to explain the mechanism of porosity behavior.
文摘Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.
