The iron content is one of the most critical parameters affecting the microstructure and mechanical properties of recycled aluminum alloy.This study aimed to compare the microstructure and tensile properties of alloys...The iron content is one of the most critical parameters affecting the microstructure and mechanical properties of recycled aluminum alloy.This study aimed to compare the microstructure and tensile properties of alloys with varying iron content to ascertain the optimal iron content for formulating a recycled Al-Si-Mg aluminum alloy.Additionally,the effects of aging temperature and aging time on the microstructure and mechanical properties of recycled aluminum alloy were investigated.With increasing aging temperature and time,both tensile strength and yield strength are improved,while elongation is decreased.Specifically,when subject to a heat treatment consisting of a solution treatment at 535℃for 5 h followed by an aging treatment at 170℃for5.5 h,the newly designed recycled aluminum alloy achieves a tensile strength of 291 MPa and a yield strength of 238 MPa.These findings hold significant implications for the further development and broader application of recycled aluminum alloys.展开更多
FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD)...FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.展开更多
To investigate the effect of nitrogen （N） level on iron （Fe） content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes....To investigate the effect of nitrogen （N） level on iron （Fe） content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes. In addition to the genotypic differences of iron content in milled rice, grain yield, 1000-grain weight and N content in grains under the same N level, there were also variations in the response of Fe content in milled rice to N levels. Based on the range and variation coefficient of Fe content in milled rice under the three N levels, the response of Fe content in milled rice to N levels could be classified into four types including highly insensitive, insensitive, sensitive and highly sensitive types. A significant quadratic correlation was found between the Fe content in milled rice and 1000-grain weight or the N content in grains. However, no significant correlation between the Fe content in milled rice and grain yield was detected. In conclusion, there are genotypic differences in the effects of N levels on Fe content in milled rice, which is favorable to breeding of Fe-rich rice under different N environments. Furthermore, high yield and Fe-rich rice could be grown through the regulation of nitrogen on Fe content in milled rice, 1000-grain weight and N content in milled rice.展开更多
At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manua...At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manually calculated and input in a computer.With the aid of a communication program between an AAS and an electronic balance(EB),the above process can be modified.First,the mass of a sample is sent to a computer by the EB.Second,the mass of the coating is calculated by the computer automatically.Finally,the iron mass is uploaded to the communication program,and the iron content can also be calculated automatically.As such,the modified process is more efficient.展开更多
The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest...The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest accuracy.However,this method presents low detection efficiency and is thus unsuitable for production quality control.Fundamental parameter and empirical coefficient methods in XRF can be used for the quality control of iron content in the galvanized coating of zinc-iron alloys.The repeatability of the two XRF methods was 0.2%and 0.4%,respectively,which were better than that of the chemical method(0.6%).However,the two XRF methods have their own limitations.The accuracy of the two XRF methods depends on the process stability of different units and may be poorer than that of the chemical method.Thus,the use of the two XRF methods should be carefully restricted.展开更多
The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectro...The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectrometry, sometimes it exceeds the quality control limit.Influences, such as current, voltage, equipment(internal circulating water, 10%CH4+90%Ar, and vacuum) checking, instrument monitoring, sample cleaning, and oper-ators, were investigated by means of 6-sigma and lean operations to improve accuracy.展开更多
The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption s...The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption spectrophotometry. The iron contents of bark extract of Acacia nilotica, Acacia senegal and Acacia seyal were 0.0044%, 0.0040% and 0.0029% respectively. In contrast, the iron content of bark extract of the three species of Acacia had lower percentage compared to that of Mimosa (Acacia mearnsii) (0.0047%), which was imported from Kenya. The iron content presented in leaves, barks, mature and immature fruits of Acacia species were determined by the same analytical methods. Bark and mature fruits of Acacia nilotica had the highest and equal percentage (0.1450%). The percentage of iron content of leaves and bark of Acacia seyal had equal percentage (0.0750%), while the bark of Acacia senegal had much lower percentage (0.0375%).展开更多
This work developed a statistical correlation between groundwater’s high iron content in the four hydrogeological domains of the State of Bahia,Brazil,and the environmental attributes of climate,lithology,soil,and ve...This work developed a statistical correlation between groundwater’s high iron content in the four hydrogeological domains of the State of Bahia,Brazil,and the environmental attributes of climate,lithology,soil,and vegetation.From 3539 wells,flow test≥1 m3∙h−1,drilling period 2003-2013,940 wells with high iron content(>0.3 mg/L)were used in this study.All groundwater samples came from new wells soon after the drilling,well construction,and a long pumping time for their development:24 hours for sedimentary aquifers and 12 hours for karstic,crystalline,and metasedimentary aquifers.The applica-tion of Pearson and Spearman linear regression to seventeen physicochemical parameters(SPSS V.12)resulted in no correlations between iron and fourteen parameters,indicating no common origin between those parameters and iron.Only color and turbidity presented correlations>0.20 with iron.After spati alizing the 940 values of iron concentration(ArcGIS V.9)on the maps of each environmental attribute,grades 1-5 were given to the variables of each attrib-ute based on the largest iron concentration value.The grades allowed the ap-plication of multivariable methods PCA and FA(SPSS V.12).The PCA indi cated two factors explaining 59.52%of the total variance,closely attending the recommended minimum of 60%.The significant factor weights from the ap-plication of FA were:in Factor 1,soil,−0.71;vegetation,−0.68;and lithology,−0.52;and in Factor 2,climate,+0.74.Indeed,in the crystalline and metased-imentary domains with mafic-ultramafic rocks rich in iron,percentages of wells,53.3%-66.7%,occurred in iron-rich soils;of 49.8%-59.8%in humid to dry forest and of 55.3%-86.8%in humid to sub-humid climate.While,for the sedimentary domain(primarily sandstones)and karstic domain(carbonate rocks)poor in iron content percentages of wells,80.9%-100%occurred in iron-rich soils,57.0%-61.8%in humid to dry forest,and 58.6%-62.4%in sub-humid to dry and semi-arid climate.These results indicated that,although lithology is a determinant for high dissolved iron content in the state of Bahia groundwater,this attribute alone(factor weight−0.52)cannot explain the whole phenomenon.The present work,using multivariable analysis with geo-spatial mapping of high iron content on top of environmental attributes,re-vealed the role of each environmental attribute in groundwater’s high iron con-tent.For the governmental drilling well company and its groundwater manag-ers,this knowledge will result in better well locations and a reduction of both well and economic losses,as the long-term maintenance cost for the treatment process due to high iron content is prohibitive for rural municipalities.展开更多
Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sph...Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.展开更多
The effects of Cr content and annealing temperature on abrasive wear characteristics of cast ausferrite nodular iron were investigated with Suga type abrasive wear tester. The surface morphology and Vickers hardness o...The effects of Cr content and annealing temperature on abrasive wear characteristics of cast ausferrite nodular iron were investigated with Suga type abrasive wear tester. The surface morphology and Vickers hardness of the tested samples were analyzed by scanning electron microscopy（SEM）, digital microscope and Vickers hardness tester. The results show that the cast ausferrite nodular iron could be obtained by alloying with Cr in the as-cast ductile cast iron and permanent mold casting, and the bainite content in the matrix increased with increasing Cr content. However, the decomposition of bainite took place during annealing at 500 °C to 800 °C; especially, at 800 °C, the bainite transformed into a mixture of fine lamellar pearlite and ferrite matrix structure. The wear loss of specimens was reduced with increasing Cr content in the cast ausferrite nodular iron. The wear loss of the sample cast ausferrite nodular iron with 0.4mass% Cr is the least. The wear loss began to increase while the Cr content is 0.6mass%. The wear loss of annealed ductile irons at different annealing temperatures was higher than that of as-cast samples. During the abrasive wear, the shear stress transformed austenite to martensite, and the hardness of specimens increased and the wear resistance of as-cast ductile cast iron was improved.展开更多
The ferrites of PC30 （Mn-Zn ferrites） were prepared by using a dry processing route. The effect of Mn-Zn ferrites doped with H3BO3 was investigated on the basis of microstructure analysis. The results of the samples...The ferrites of PC30 （Mn-Zn ferrites） were prepared by using a dry processing route. The effect of Mn-Zn ferrites doped with H3BO3 was investigated on the basis of microstructure analysis. The results of the samples doped with H3BO3 less than 5 × 10^-5 showed that the doping had no significant effect on power loss, initial permeability, fine grain microstructure, and density of Mn-Zn ferrites. With the further increase in H3BO3 doping （up to 1 × 10 ^-4 ）, the microstructure of Mn-Zn ferrites is in the critical state between fine grain and ＂sandwich＂, and the initial permeability and density of Mn-Zn ferrites begin falling quickly; the increased H3BO3 doping also results in deteriorated power loss properties. Thus, the control of the boron content in iron oxide is of utmost importance for the quality of Mn-Zn ferrites in producing process.展开更多
In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron micr...In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.展开更多
This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen...This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.展开更多
基金support from funded project:Key Industrial R&D Projects of Chongqing Technology Innovation and Application Demonstration (cstc2020jscx-dxwtBX0023)。
文摘The iron content is one of the most critical parameters affecting the microstructure and mechanical properties of recycled aluminum alloy.This study aimed to compare the microstructure and tensile properties of alloys with varying iron content to ascertain the optimal iron content for formulating a recycled Al-Si-Mg aluminum alloy.Additionally,the effects of aging temperature and aging time on the microstructure and mechanical properties of recycled aluminum alloy were investigated.With increasing aging temperature and time,both tensile strength and yield strength are improved,while elongation is decreased.Specifically,when subject to a heat treatment consisting of a solution treatment at 535℃for 5 h followed by an aging treatment at 170℃for5.5 h,the newly designed recycled aluminum alloy achieves a tensile strength of 291 MPa and a yield strength of 238 MPa.These findings hold significant implications for the further development and broader application of recycled aluminum alloys.
基金Project supported by the Natural Science Foundation of Jiangsu Province (BK20170232,BK20170238)National Natural Science Foundation of China (51908256)。
文摘FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.
基金supported by the Key Projects in the National Science & Technology Pillar Program of China (Grant No. 2006BAD02A03)the National Natural Science Foundation of China (Grant Nos. 30971732 and 30671223)
文摘To investigate the effect of nitrogen （N） level on iron （Fe） content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes. In addition to the genotypic differences of iron content in milled rice, grain yield, 1000-grain weight and N content in grains under the same N level, there were also variations in the response of Fe content in milled rice to N levels. Based on the range and variation coefficient of Fe content in milled rice under the three N levels, the response of Fe content in milled rice to N levels could be classified into four types including highly insensitive, insensitive, sensitive and highly sensitive types. A significant quadratic correlation was found between the Fe content in milled rice and 1000-grain weight or the N content in grains. However, no significant correlation between the Fe content in milled rice and grain yield was detected. In conclusion, there are genotypic differences in the effects of N levels on Fe content in milled rice, which is favorable to breeding of Fe-rich rice under different N environments. Furthermore, high yield and Fe-rich rice could be grown through the regulation of nitrogen on Fe content in milled rice, 1000-grain weight and N content in milled rice.
文摘At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manually calculated and input in a computer.With the aid of a communication program between an AAS and an electronic balance(EB),the above process can be modified.First,the mass of a sample is sent to a computer by the EB.Second,the mass of the coating is calculated by the computer automatically.Finally,the iron mass is uploaded to the communication program,and the iron content can also be calculated automatically.As such,the modified process is more efficient.
文摘The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest accuracy.However,this method presents low detection efficiency and is thus unsuitable for production quality control.Fundamental parameter and empirical coefficient methods in XRF can be used for the quality control of iron content in the galvanized coating of zinc-iron alloys.The repeatability of the two XRF methods was 0.2%and 0.4%,respectively,which were better than that of the chemical method(0.6%).However,the two XRF methods have their own limitations.The accuracy of the two XRF methods depends on the process stability of different units and may be poorer than that of the chemical method.Thus,the use of the two XRF methods should be carefully restricted.
文摘The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectrometry, sometimes it exceeds the quality control limit.Influences, such as current, voltage, equipment(internal circulating water, 10%CH4+90%Ar, and vacuum) checking, instrument monitoring, sample cleaning, and oper-ators, were investigated by means of 6-sigma and lean operations to improve accuracy.
文摘The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption spectrophotometry. The iron contents of bark extract of Acacia nilotica, Acacia senegal and Acacia seyal were 0.0044%, 0.0040% and 0.0029% respectively. In contrast, the iron content of bark extract of the three species of Acacia had lower percentage compared to that of Mimosa (Acacia mearnsii) (0.0047%), which was imported from Kenya. The iron content presented in leaves, barks, mature and immature fruits of Acacia species were determined by the same analytical methods. Bark and mature fruits of Acacia nilotica had the highest and equal percentage (0.1450%). The percentage of iron content of leaves and bark of Acacia seyal had equal percentage (0.0750%), while the bark of Acacia senegal had much lower percentage (0.0375%).
文摘This work developed a statistical correlation between groundwater’s high iron content in the four hydrogeological domains of the State of Bahia,Brazil,and the environmental attributes of climate,lithology,soil,and vegetation.From 3539 wells,flow test≥1 m3∙h−1,drilling period 2003-2013,940 wells with high iron content(>0.3 mg/L)were used in this study.All groundwater samples came from new wells soon after the drilling,well construction,and a long pumping time for their development:24 hours for sedimentary aquifers and 12 hours for karstic,crystalline,and metasedimentary aquifers.The applica-tion of Pearson and Spearman linear regression to seventeen physicochemical parameters(SPSS V.12)resulted in no correlations between iron and fourteen parameters,indicating no common origin between those parameters and iron.Only color and turbidity presented correlations>0.20 with iron.After spati alizing the 940 values of iron concentration(ArcGIS V.9)on the maps of each environmental attribute,grades 1-5 were given to the variables of each attrib-ute based on the largest iron concentration value.The grades allowed the ap-plication of multivariable methods PCA and FA(SPSS V.12).The PCA indi cated two factors explaining 59.52%of the total variance,closely attending the recommended minimum of 60%.The significant factor weights from the ap-plication of FA were:in Factor 1,soil,−0.71;vegetation,−0.68;and lithology,−0.52;and in Factor 2,climate,+0.74.Indeed,in the crystalline and metased-imentary domains with mafic-ultramafic rocks rich in iron,percentages of wells,53.3%-66.7%,occurred in iron-rich soils;of 49.8%-59.8%in humid to dry forest and of 55.3%-86.8%in humid to sub-humid climate.While,for the sedimentary domain(primarily sandstones)and karstic domain(carbonate rocks)poor in iron content percentages of wells,80.9%-100%occurred in iron-rich soils,57.0%-61.8%in humid to dry forest,and 58.6%-62.4%in sub-humid to dry and semi-arid climate.These results indicated that,although lithology is a determinant for high dissolved iron content in the state of Bahia groundwater,this attribute alone(factor weight−0.52)cannot explain the whole phenomenon.The present work,using multivariable analysis with geo-spatial mapping of high iron content on top of environmental attributes,re-vealed the role of each environmental attribute in groundwater’s high iron con-tent.For the governmental drilling well company and its groundwater manag-ers,this knowledge will result in better well locations and a reduction of both well and economic losses,as the long-term maintenance cost for the treatment process due to high iron content is prohibitive for rural municipalities.
基金This work was supported by the National Natural Science Foundation of People’s Republic of China(No.NSFC52174246)the Interdisciplinary Scientific Research Foundation of Guangxi University(No.2022JCC016).
文摘Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.
基金Item Sponsored by Important National Science and Technology Specific Project of China(2012ZX04010-031)
文摘The effects of Cr content and annealing temperature on abrasive wear characteristics of cast ausferrite nodular iron were investigated with Suga type abrasive wear tester. The surface morphology and Vickers hardness of the tested samples were analyzed by scanning electron microscopy（SEM）, digital microscope and Vickers hardness tester. The results show that the cast ausferrite nodular iron could be obtained by alloying with Cr in the as-cast ductile cast iron and permanent mold casting, and the bainite content in the matrix increased with increasing Cr content. However, the decomposition of bainite took place during annealing at 500 °C to 800 °C; especially, at 800 °C, the bainite transformed into a mixture of fine lamellar pearlite and ferrite matrix structure. The wear loss of specimens was reduced with increasing Cr content in the cast ausferrite nodular iron. The wear loss of the sample cast ausferrite nodular iron with 0.4mass% Cr is the least. The wear loss began to increase while the Cr content is 0.6mass%. The wear loss of annealed ductile irons at different annealing temperatures was higher than that of as-cast samples. During the abrasive wear, the shear stress transformed austenite to martensite, and the hardness of specimens increased and the wear resistance of as-cast ductile cast iron was improved.
文摘The ferrites of PC30 （Mn-Zn ferrites） were prepared by using a dry processing route. The effect of Mn-Zn ferrites doped with H3BO3 was investigated on the basis of microstructure analysis. The results of the samples doped with H3BO3 less than 5 × 10^-5 showed that the doping had no significant effect on power loss, initial permeability, fine grain microstructure, and density of Mn-Zn ferrites. With the further increase in H3BO3 doping （up to 1 × 10 ^-4 ）, the microstructure of Mn-Zn ferrites is in the critical state between fine grain and ＂sandwich＂, and the initial permeability and density of Mn-Zn ferrites begin falling quickly; the increased H3BO3 doping also results in deteriorated power loss properties. Thus, the control of the boron content in iron oxide is of utmost importance for the quality of Mn-Zn ferrites in producing process.
文摘In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.
文摘This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.
