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
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
The objective of this study is to present a tailings recovery project in a dam located in northern Brazil;the tailings in this dam have high concentrations of iron. The sustainable recovery of mineral resources can be...The objective of this study is to present a tailings recovery project in a dam located in northern Brazil;the tailings in this dam have high concentrations of iron. The sustainable recovery of mineral resources can be achieved using the dredging method. The methodology used was based on two drilling projects conducted in 2001 and 2010;these projects contained samples with information on the chemical composition and particle size fractions. The dredging system was designed to operate with four cutter suction dredgers. For operation, factors such as productivity, pumping distance and material flow were considered. The material contained in the dam was estimated using the natural neighborhood interpolation method;this resulted in approximately 192 million tons of tailings, with an average iron content of 63.37%. Based on these data, a 13-year mining plan was prepared, with the potential to maximize the use of the tailings and reduce the environmental impacts, thus contributing to a circular economy.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
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
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
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
Heating-cooling combined mold（HCCM） horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The...Heating-cooling combined mold（HCCM） horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The effects of Fe content（1.08wt%–2.01wt%） on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.展开更多
Copper was surfaced on the Q235 substrate by shielded metal arc welding （SMAW） and tungsten inert-gas （TIG） arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning ele...Copper was surfaced on the Q235 substrate by shielded metal arc welding （SMAW） and tungsten inert-gas （TIG） arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers＇ numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.展开更多
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%).
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.
文摘The objective of this study is to present a tailings recovery project in a dam located in northern Brazil;the tailings in this dam have high concentrations of iron. The sustainable recovery of mineral resources can be achieved using the dredging method. The methodology used was based on two drilling projects conducted in 2001 and 2010;these projects contained samples with information on the chemical composition and particle size fractions. The dredging system was designed to operate with four cutter suction dredgers. For operation, factors such as productivity, pumping distance and material flow were considered. The material contained in the dam was estimated using the natural neighborhood interpolation method;this resulted in approximately 192 million tons of tailings, with an average iron content of 63.37%. Based on these data, a 13-year mining plan was prepared, with the potential to maximize the use of the tailings and reduce the environmental impacts, thus contributing to a circular economy.
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.
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.
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.
基金the support from the National Key Technology R&D Program of China (No. 2011BAE23B00)the National Natural Science Foundation of China (Nos. 51104016 and 51504023the fund of the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals (No. SKL-SPM- 201204)
文摘Heating-cooling combined mold（HCCM） horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The effects of Fe content（1.08wt%–2.01wt%） on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.
文摘Copper was surfaced on the Q235 substrate by shielded metal arc welding （SMAW） and tungsten inert-gas （TIG） arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers＇ numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.
