記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

The solubility of calcium titanate in CaCl2 melt was investigated above 1373 K, and electrodeposition of Ti metal in the melt was attempted. Many pits were formed on the surface of sintered CaTiO3 compact by the immersion in CaCl2 melt above 1373 K. The weight of the compact decreased with the increase in the immersion time, and the decrease got faster with the increase in temperature. Cathodic current in cyclic voltammetry increased with the addition of CaTiO3 powder in the bath, and the increase in the cathodic currents depended on the bath temperature and the added amount of CaTiO3. From the results by the electrochemical measurement, the solubilities of CaTiO3 in CaCl2 melt were estimated about 7 mol% at 1573 K, and less than 1 mol% at 1373 K. Metallic Ti was detected by XRD analysis in the electrodeposit obtained by potentio-static electrolysis in the bath containing CaTiO3 above 1373 K, but the amount of Ti metal seemed a little. The similar results were obtained in CaCl2 melt containing Ca3Ti2O7 though the detailed study has not been completed. It was concluded that calcium titanate was soluble in molten CaCl2 above 1373 K, and that the CaCl2 bath containing calcium titanate could be applied to Ti electrolysis.

DOI： 10.2320/matertrans.MK201615

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOC INC  

The electrolysis condition to obtain Ti metal in a CaF2-MgF2 with CaO and TiO2 has been studied at 1573K. It was shown by cyclic voltammetry that cathodic current increased below 0.8V ( vs. Mg/Mg2+) with CaO and TiO2 addition and that three reduction steps of Ti was suggested. The particles containing Ti were obtained by potentio-static electrolysis; only Ti oxide particles were detected by the electrolysis above 0.5V, while Ti metal particles did by the electrolysis below 0.4V. This result indicates that Ti metal can be electrodeposited below 0.4V (vs. Mg/Mg2+).

DOI： 10.1149/07515.0199ecst

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOC INC  

Carbon or graphite is commonly used to anode material in molten salt electrolysis, but they are consumed by a electrochemical reaction with a residual O(2-)in the bath. In this study, the dependence of anodic behavior in molten chloride containing O2- on some carbon materials with different structure has been investigated in LiCl-KCl-ClO melts at 723K. The anodic behavior of SiC was also investigated in the bath. In all materials, reactions of CO2 and CO32- occurred, and electrodes were consumed; a graphitization degree slightly influenced the consumption at graphite material, and the consumption of GC seemed the lowest. Although SiO2 was formed on SiC material, the consumption of SiC was not prevented completely. The unevenness of SiO2 layer on SiC might cause the consumption of SiC.

DOI： 10.1149/07515.0207ecst

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOC INC  

The so-called metal fog sometimes formed during the molten salt electrolysis. In this paper, the effect of the surface shape of electrode on the metal fog formation was investigated in LiCl-KCl. Cyclic voltammetry and potentiostatic electrolysis were carried out at Mo wire electrode with/without screw cutting. The dark blue metal fog was formed at both types of electrodes, while the gray metal fog was generated only at the screw-cut electrode. The gray fog formation also depended on the diameter of the electrode; the formation was intenser at a small electrode than at a large electrode. It is concluded that the shape of electrode strongly affects the gray metal fog formation, and it is suggested that the current concentration at the edge causes the formation.

DOI： 10.1149/07515.0233ecst

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Mg-Li system alloys have poor corrosion properties, especially cold-rolled sheet leads to exfoliation corrosion as a result of long-term immersion test. Addition of aluminum element to Mg-14 mass% Li alloy could be suppressed the occurrence of exfoliation corrosion. However, excess addition of aluminum to Mg-14 mass% Li alloy causes the degradation of corrosion resistance. In this study, the composition of aluminum in Mg-14 mass% Li was optimized to improve the corrosion property. 3 mass% of Al addition could be suppressed the corrosion rate because enough aluminum element dissolved into matrix and precipitation of the second phase was inhibited.

DOI： 10.2320/matertrans.M2016247

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

As increasing the demand of Mg alloys, recycling of these alloys require for securing a metallic resource and energy conservation. A commercial metal scrap includes other structural materials such as iron, copper and aluminum alloys. These metal elements deteriorate mechanical properties or corrosion properties of Mg alloys. Therefore, these different materials were possibly removed from Mg scrap during recycling process. The separation of Al and Mg materials has difficulty except for the gravity separation. However, there is a limited difference in density between Mg and Al. In this study, Mg recovery from mixed metal scrap was attempted by dry gravity separation using solid particulate vibrating bed. Mg separation with high recovery ratio was achieved by adjusting the density of the particulate bed. It was suggested that the bulk density of the particulate bed affected the behavior of separation materials for the favorable recovery.

DOI： 10.2320/matertrans.M2015226

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

The purification process is required for recycling Mg process. Selective impurity removal has an efficient purification process in the purity level of commercial Mg metal and alloys. Especially, iron impurity deteriorates the corrosion resistance of Mg alloys. Carbon addition to Mg-3 mass% Al alloy melt is an effective method for the removal of iron impurity by the formation of Fe-Al-C compounds. In this study, gas injection of carbon dioxide (CO2) into Mg alloy melt as the method of carbon addition was investigated for the separation of iron compounds. Carbon dioxide was decomposed by Mg melt and carbon substance affected the formation of iron carbide in the melt. Magnesium oxide and Fe-Al-C compound were formed in the melt slag and floated to the top of the solidified Mg-3 mass% Al alloy.

DOI： 10.2320/matertrans.MBW201407

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Mg-Li system alloys with over 11 mass% Li have an excellent cold-workability in Mg alloys due to the bcc-structured crystal system. However this system alloys have poor corrosion resistance caused by Li solid-solution alloy. The corrosion resistance of conventional hcp-Mg alloys is influenced by the composition of impurity elements. Particularly, minute iron element deteriorates the corrosion resistance of Mg alloy and there is a threshold concentration on the corrosion rate in Mg alloys. In this study, the effect of iron element on the corrosion resistance of Mg-Li alloy was investigated by addition of iron. The corrosion resistance of Mg-Li with no Fe addition was higher than conventional Mg alloy. The corrosion rate of Mg-Li alloy increased with increasing iron concentration. However, there is no threshold iron concentration affected to the corrosion resistance on Mg-Li alloy.

DOI： 10.2320/matertrans.MAW201405

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記述言語：日本語   出版者・発行元：公益社団法人 日本鋳造工学会  

<p>  The sulfide morphology in Cu-Sn-Zn-S alloy castings was investigated to understand the transition from eutectic solidification to monotectic solidification. The sulfide morphology was observed to clarify whether sulfides were formed by eutectic reaction or monotectic reaction. The cooling rate during solidification was changed by changing mold materials, mold shapes, and mold sizes. The holding time from deoxidation of melt to casting was changed to understand the effect of deoxidation on the sulfide morphology. Eutectic sulfides were formed when the melt was cooled slowly, and the amount of monotectic sulfide increased with increasing cooling rate. The transition from eutectic morphology to monotectic morphology occurred at cooling rates of 0.5K/s to 1.0K/s. Just after deoxidation with Cu-P alloys, sulfides were formed by monotectic reaction. However, with increasing holding time of the melt after deoxidation, the amount of the sulfides formed by eutectic reaction increased.</p>

DOI： 10.11279/jfes.86.26

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOC INC  

The cathodic reaction of Ti has been studied in a CaF2-MgF2 bath with CaO and TiO2 at 1373K. Cyclic voltammograms were measured in the baths of various compositions, and the dependence of the cathodic reaction of Ti on the bath composition was discussed. With reference to the results of the cyclic voltammetry, Ti metal deposition by potentio-static electrolysis was attempted. It was shown that the reduction sequence of Ti consisted of three steps, and Ti metal was deposited under the suitable condition. The cathodic behavior of Ti was influenced by the molar ratio of TiO2 to CaO in the melt. Considering the previous results of Ti electrolysis by using DC-ESR unit, it is strongly suggested that a binuclear complex ion of Ti with O, such as Ti2O76-, affects the reduction sequence of Ti in CaF2-CaO-TiO2 and CaF2-MgF2-CaO-TiO2 baths.

DOI： 10.1149/06404.0275ecst

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Cold-rolled Mg-Li system alloys represent the exfoliation corrosion on the surface of the longitudinal and the transverse sections. In this study, the origination of the exfoliation corrosion of the cold-rolled Mg-Li alloy was clarified. In the initial stage of the corrosion, the oxide film formed immediately on the surface of each section, and then the film destruction with a remarkable bubble generation was observed in a certain spot. There were microcracks on the trace of the film destruction along the grain boundary. The corrosion resistance in the annealed specimen was more than that in the as-rolled specimen because the microstructure of the as-rolled specimen has elongated and thinned grains by severe cold rolling. The exfoliation corrosion was not observed in the annealed specimen, because the annealed specimen has homogeneous equiaxial grains. The successive film destruction in annealed specimen progressed along the grain boundary to random direction. Moreover, the initiation time of the bubble generation was delayed in the annealed specimen.

DOI： 10.2320/matertrans.MAW201301

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記述言語：日本語   出版者・発行元：公益社団法人 日本鋳造工学会  

The applicability of the permanent mold casting process for the new type of lead-free bronze with dispersed sulfide was evaluated by comparison with other conventional copper alloys, such as leaded bronze, leaded brass, and lead-free bronze containing bismuth. The copper alloys were cast into the permanent mold for the solidification cracking test. The relationship between the degree of cracking and solidification temperature range was examined. <br>&nbsp;&nbsp;The new lead-free bronze with dispersed sulfide was more unbreakable than the other copper alloys. The smaller the solidification temperature range, the harder it was for solidification cracking to occur. Comparison of the new lead-free bronze with the leaded bronze and lead-free bronze containing bismuth indicated differences in the dendrite shape near the fracture and distribution of the residual melt segregated to one area towards the end of the solidification. The new lead-free bronze may also have a solidification morphology that makes it more difficult to crack, allowing it to be applied to permanent mold casting compared to other copper alloys. Its level of applicability is more or less the same as brass castings.

DOI： 10.11279/jfes.84.383

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：SCIENCE PRESS BEIJING  

Direct electrolysis of Ti-Fe alloy has been attempted in a CaF2-CaO-TiO2-FeO bath by the process using a direct -current electro-slag remelting unit. The electrolysis strongly depended on the electrolysis conditions, and Ti -Fe alloy was successfully obtained in the bath of a particular composition. The strong influence of the bath composition was also seen in the Ti and Ti -Al electrolysis in the previous, and suggested that the cathodic reaction of Ti was affected by the change in the bath composition. To clarify the influence of the bath composition, electrochemical measurement was carried out in a CaF2-MgF2-CaO-TiO2 bath. The cathodic current due to Ti reduction was observed by cyclic voltammetry, and the change in the shape of cyclic voltammogram with the bath composition was found. This result indicated the change in the electrode reaction of Ti, and explained the results of the Ti electrolysis with a direct -current electro-slag remelting unit.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOC INC  

The anodic reactions on some materials in LiCl-KCl eutectic melt have been investigated. Palladium and Mo were dissolved though Mo showed passivation behavior. In the melt including Li2O, O-2 gas generation occurred at both metal anodes along with their anodic dissolution. At the graphite anode, some anodic reactions besides the Cl-2 gas generation reaction were observed in the melt with Li2O. The visual observation and the weight change of the anode indicated that the anodic reaction without gas generation and the electrode consumption preceded the CO2 gas generation. The potential of the CO2 gas generation reaction on graphite looked more positive than that of the O-2 gas generation on Pd and Mo, which suggested the overpotential of the CO2 generation reaction on graphite was rather large in the melt.

DOI： 10.1149/05011.0127ecst

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

In this study, we investigated conductive properties of joint interfaces of friction stir welding (FSW) between dissimilar metals, stainless steel SUS304 and aluminum A6063, using a SQUID nondestructive evaluation (NDE) system. With current injection method, the current maps above the FSW specimens jointed under various conditions were measured by a HTS-SQUID gradiometer. The conductivities of the joint interfaces, which were estimated from the current maps, differed between the joint conditions. By destructive tests using optical microscope, large voids were observed on the joint interfaces with low welding speed that generated excess heating. In case of one specimen, which was welded with welding speed of 500 and 200 mm/min, the conductivity of the former was higher than that of the latter, although the inside voids in the respective regions were not much different. From these results, it is suggested that the current maps were influenced not only by the conductivity of the joint interface but also by inside voids. By hardness test on the SUS boards near the interfaces, only the SUS jointed with 200 mm/min was about half softer than its matrix. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physc.2010.05.154

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：TRANS TECH PUBLICATIONS LTD  

Direct electrolysis of Ti and its alloys has been attempted by the process using a DC-ESR unit. The concept of the process is explained in detail, and the expected key issues are commented. Liquid Ti metal was obtained in a CaF(2)-CaO-TiO(2) bath, and electrolysis by using a new type of the electrolytic cell was also tried. Ti-Al alloy was successfully deposited in a CaF(2)-CaO-TiO(2)-Al(2)O(3) bath, whereas Ti-Si alloy was not obtained in a CaF(2)-CaO-TiO(2)-SiO(2) bath yet. Ti-Fe alloy was extracted in CaF(2)-CaO-TiO(2)-FeO bath of a particular composition. A common correlation between the cathodic current efficiency and the average consumed electric power seen in the Ti, Ti-Al and Ti-Fe electrolysis suggested the importance of sufficient temperature in the process. The bath composition also affected the temperature through the change in the electric conductivity of the bath.

DOI： 10.4028/www.scientific.net/KEM.436.85

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELECTROCHEMICAL SOC JAPAN  

The anodic behaviors of Pd, Pt and Au have been investigated in LiCl-KCl eutectic melt at 683 K. Chemical reduction of the dissolved noble metal ions by H-2 and CH4 has been also carried out. It was shown that I'd and ALL could be dissolved anodically with a large dissolution rate, and that the dissolution rate of Pt was limited because of its passivation behavior. Fine particles of these noble metals were obtained by H-2 or CH4 reduction though they combined together.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Influence of the conversion coating with some rare-earth elements, such as La, Y, Sm, Nd and Ce, on corrosion resistance of Mg alloy has been studied. Effect of pretreatment, such as alkaline degrease, acid pickling and surface activation, has been also investigated. The surface of Mg alloy was covered with the so-called dry mad structure by the coating. The coating layer was a thin oxide film containing Mg, Al and rare earth element. F and P were detected in the coating with the pretreatment in addition. The corrosion resistance of Mg alloy against salt water was significantly improved by the conversion coating by immersion in the solution including both Mg(NO3)2 and rare earth nitrate. The corrosion resistance was improved by applying the pretreatment, further. ©The Electrochemical Society.

DOI： 10.1149/1.3114947

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

Water vapor or carbon dioxide gas was injected into molten pig iron in order to oxidize silicon without oxidizing iron. When water vapor was injected, decarburization was predominant at high temperature. The oxidation of silicon occurred at low temperature of 1473 K. When carbon dioxide gas was injected, both of silicon oxidation and decarburization occurred simultaneously. But the former was predominant at lower temperature, while the latter at higher temperature, At 1523 K, the silicon content was lowered at 0.16 mass %. The oxidation of iron was not observed at all. The rate controlling step of silicon oxidation and decarburization are judged the mass transfer in the gas phase. With the increase in gas injection rate, the reaction rates decreased, because of bubble integration. The slag addition decreased the reaction rates, because the reactions were blocked on the melt surface.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Conversion coating by immersion in solution including Mg(NO3)(2) and/or La(NO3)(3) was applied to commercial Mg alloys: AZ31, AZ61, AZ91 and AM60. The formed layer was analyzed, and the corrosion resistance of the specimen against salt water was investigated. The influences of the coating conditions on the characteristics of the layer and on the corrosion behavior were discussed. A thin oxide layer was formed on the surface of the specimen by the conversion coating, and La was contained in the layer obtained in the solution including La(NO3)(3). The corrosion resistance of Mg alloys wasn't remarkably improved by the conversion coating using either Mg(NO3)(2) solution or La(NO3)(3) solution, while it was particularly bettered by the coating using the solution including both Mg(NO3)(2) and La(NO3)(3). The good corrosion resistance was obtained under the wide concentration ratio of La(NO3)(3) to Mg(NO3)(2), and the optimum coating conditions for each alloy was specified. The pretreatment, such as the alkaline degrease, the acid pickling and the surface activation, was effective for the uniform coating on large specimen.

DOI： 10.2320/matertrans.MC200760

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Change in the morphology of electrodeposited Mg with codeposition of La has been investigated in a MgCl2-NaCl-CaCl2 bath containing LaCl3. The morphology of Mg electrodeposit remarkably changed with the codeposition of a small amount of La, and the electrochemical behaviors were influenced consequently. These results suggested the possibility that the efficiency of electrolysis could be improved by the codeposition. In this study, metal fog formation of Li has been also studied in a LiCl-KCl bath with reference to the formation in pure LiCl melt or in equi-molar NaCl-KCl melt. The results suggested that the mechanism of the metal fog formation in the Li electrolysis and the Na electrolysis was different. Based on the consideration of the formation mechanism, the ways to control the metal fog formation were discussed. ©The Electrochemical Society.

DOI： 10.1149/1.3159348

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Ti electrolysis by using a DC-ESR unit was performed in a CaF 2-CaO-TiO2 bath, and the influence of the bath composition was discussed. Ti metal in liquid was electrodeposited though some impurity elements were contained. The cathodic current efficiency strongly depended on the bath composition, and reached about 25% in the bath where the molar ratio of CaO to TiO2 was 1.5. The consumed electric power was also affected by the bath composition so that the close relationship between the cathodic current efficiency and the electric power was seen. The influence of the bath composition was considered due to the change in the species in the bath, and Ca3Ti2O7 seemed suitable for Ti deposition. ©The Electrochemical Society.

DOI： 10.1149/1.3159326

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Mg metal containing rare earth metals (REs) can be electrowon directly by molten salt electrolysis. The clarification of the optimum RE content in Mg is necessary to fix the electrolytic conditions in the direct electrowinning of Mg with RE. From this point of view, effect of RE addition in Mg metal on its corrosion property was studied in detail in this study. The specimen was prepared by adding La, Nd, or Cc in melted Mg metal, and its corrosion resistance was examined by an immersion test in 3 mass%-NaCl solution at room temperature. The corrosion resistance of Mg was improved greatly by adding a small amount of RE, whereas the excess addition of RE deteriorated the corrosion resistance. The optimum RE content was about 0.5 mass%. In this study, the corrosion property of Mg with an artificial surface oxide layer was also studied to clarify the effect of surface oxide. The corrosion resistance of Mg was particularly strengthened by conversion coating in a solution including La(NO3)(3), Nd(NO3)(3), or Ce(NO3)(3), with Mg(NO3)(2). This result suggests that the surface oxide film consisting of both Mg and RE gives ideal corrosion resistance to Mg metal. Mg metal with conversion coating including RE should also be of use as a corrosion-resistant material. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.electacta.2007.03.027

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

The anodic behaviors of some noble metals and their alloys in dehydrated LiCl-KCl eutectic melt have been studied as a basic study on a new reprocessing process of spent UO2 nuclear fuel by an electrorefining technique. Palladium and Ru dissolved anodically as Pd2+ and Ru3+, respectively. Rhodium dissolved as Rh3+, and was passivated by surface film formation. The potentials where the steady dissolution current density was 10-3 A/cm2 were 3.02V for Pd, 3.08V for Rh and 3.12V for Ru, These values were more positive than the reported value of UO2. The anodic behaviors of Pt-Rh and Pd-Ru alloys were explained from those of each component, and no peculiar influence by alloying was seen. These results indicate that the noble metals and alloys can be separated from UO2 by leaving them in the anode by the control of the anode potential. copyright The Electrochemical Society.

DOI： 10.1149/1.2798682

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

In order to make titanium ingot directly from molten slag, the metal pool was tried to form and used as the cathode. The electro-slag remelting (ESR) unit was used for the purpose. The unit is composed of water-cooled copper mold and the DC power source of 2000 A and 100V. The graphite electrode was used for anode and the base plate was used for cathode. The slag was composed of the CaF2-CaO-Al2O3 system. By the addition of Al2O3 to the slag, the electro-deposit of Ti-Al was obtained. The current efficiency increased with the supplied electric power. It is concluded that the mechanism of high current efficiency should be the formation of liquid metal deposit due to high heat generation and the suppression of metal fog formation and suboxide formation of titanium.

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

The dependence of Ti alloy coating by using a disproportionation reaction in molten chloride upon the coating conditions has been investigated. The corrosion resistance of the coated specimen was also examined. An equimolar NaCl-KCl mixture was melted in a quartz crucible under the atmosphere of high-purity Ar, and TiCl3 was added with Ti sponge into the mixture. Iron, carbon steel, Ni and stainless steel plates were immersed in the bath at 1100∼1250 K for a scheduled period. After the immersion, the Fe plate was covered with a dense layer of Ti-Fe alloy of which thickness was more than 10 μm. The layer adhered to the surface, and mainly consisted of Fe2Ti. Carbon steel was covered with a similar Ti-Fe layer to that on the Fe plate, and carbides were not found. The surface of the Ni plate was fully covered with NiTi2, and a dense layer of Ni3Ti was formed under the NiTi2 layer. The Ti alloy layer on Ni was thicker than those on Fe and carbon steel under the same condition. A dense layer of a few μm, where Ti content was about 90 mass%, was observed on the surface of the stainless steel plate after the immersion. The thickness of the Ti alloy layer was in proportion to the square root of the immersion time, and its formation rate was not affected very much by the initial TiCl3 concentration. These results indicated that the formation rate of Ti alloy layer was mainly controlled by the diffusion of elements in the formed layer. The corrosion resistance of Fe and carbon steel against salt water was significantly improved by the Ti alloy coating on the surface. © 2006 The Japan Institute of Metals.

DOI： 10.2320/jinstmet.70.126

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

An experimental study was conducted to monitor the evolution of coke carbon structure during thermal annealing in a temperature range from 1 273 to 2 473 K in a bench-scale reactor. Coke carbon structure was characterized by using Raman Spectroscopy and the X-ray Diffraction. The Raman spectra of most of the cokes displayed two broad peaks G* (11620 cm(-1)) and D* (1360 cm(-1)). Both Raman peaks were deconvoluted into five peaks namely G, D, D', R, and R-2. On the basis of area under the respective band peaks, new structural parameters were obtained to quantify graphitic (G), graphitic defect (D) and random (R) carbon fractions of cokes.
XRD analysis was used to show that stack height carbon crystallite, Lc, of coke increases with increasing annealing temperature while the impact of annealing duration was not significant particularly up to 1873 K. On the other hand, average carbon crystallite width, La, did not improve significantly up to 1 873 K, and increased rapidly after subsequent rise in the annealing temperature. It appears that during annealing up to 1873 K, modification of coke carbon structure could occur due to loss of basal carbon as a consequence of in-situ gasification.
The lateral expansion of carbon crystallite, La, was related to relative intensity or shape of Raman band peaks such that both parameters did not change significantly up to an annealing temperature of 1 873 K. At higher annealing temperatures, La values of coke increased with decreasing D/G ratio. Lateral expansion of carbon crystallite was attributed to progressive reduction of defects of graphitic carbon of coke, which can be monitored by D fraction of Raman Analysis. Combined Raman and XRD analysis suggested that rapid graphitization of coke may not occur along all dimensions until the annealing temperature exceeds 1873 K.
Combining XRD and Raman analysis would provide a comprehensive evaluation of the evolution of coke carbon structure at different temperatures and their subsequent implications on the efficiency of various ironmaking operations.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

In order to make titanium ingot directly from molten slag, the metal pool was tried to form and used as the cathode. The electro-slag remelting (ESR) unit was used for the purpose. The unit is composed of water-cooled copper mold and the DC power source of 2000 A and 100V. The graphite electrode was used for anode and the base plate was used for cathode. The commercial and re-melted slag of CaO-CaF2 was melted in the mold with the addition of TiO2. The following reactions are expected to occur.
Ti4+ + 4e = Ti at cathode
2O(2-) + 2C = 2CO + 4e at anode
During the process, large amount of molten slag splashed out from the mold, showing the CO evolution at anode. The metal deposit was obtained but in the form of block and piled upon the baseplate. The metal pool was not obtained perfectly because of shortage of heat supply. The cathodic current efficiency was 60 % at maximum. The metal deposit contained much impurity. In order to reduce the impurity and increase the current efficiency, the effect of electrode distance was examined. The electro-slag re-melting of titanium was tried in order to examine the condition to make metal pool.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

In the blast furnace, the reduction of iron oxide and gasification of coke occur simultaneously. It is well accepted that the gasification reaction controls the simultaneous reaction. Therefore, it is important to develop highly reactive carbonaccous materials. It is also known that the reaction is accelerated catalytically with the addition of some materials. In the present work, the catalytic effect of iron, nickel and CaO on the gasification of graphite and coke was examined. The catalytic effect of iron, nickel and CaO on the reaction rate of graphite was noticed The effect was larger at lower temperature. At 1373 K, the effect almost vanished. The effect was larger in the order of CaO, iron and nickel. The reaction rate of de-ashed coke increased by the addition of iron and nickel. The effect of iron was larger than that of nickel. The effect was larger at higher temperature, which was contrary to the case of graphite. The reactive surface area increased also by the addition. Therefore, the catalytic effect on reaction rate might be attributable to the increase in the reactive surface area.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

Improvement of corrosion resistance of Mg metal by addition of rare earth metal (RE) was studied, and the effect of surface oxide layer with RE was investigated. The corrosion resistance of Mg was remarkably improved by adding a small amount of RE, and the suitable RE content was clarified. The corrosion resistance of Mg was particularly bettered by conversion coating using a solution including both RE(NO3)(3) and Mg(NO3)(2). This result indicates that the surface oxide layer consisting of both Mg and RE gives good corrosion resistance to Mg metal. In this study, direct electrodeposition of Mg metal containing RE was also tried in molten chloride with RE chloride, and it was shown that electrolysis could be performed stably. The RE content in the deposited Mg metal was depended on the concentration of RE chloride in the bath and the cathode potential, and Mg metal containing the suitable RE content for its corrosion protection was obtained easily by direct electrolysis.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：METALLURGICAL INDUSTRY PRESS  

The electrochemical behavior of Ti was investigated in fluoride and chloride-fluoride melts. The electrode reaction of Ti in a fluoride-oxide mixture above 1300 K was also studied. In a eutectic mixture of LiF-NaF-KF with K2TiF6, only one pair of cathodic and anodic current peaks by the reaction of Ti was observed in a cyclic voltammogram at 773 K, while some cathodic and anodic current peaks appeared at higher temperature. Ti metal was obtained by potentiostatic electrolysis in this melt. Some cathodic and anodic current peaks by the reaction of Ti were observed in a KCl-NaCl-KF-NaF melt at 873 K in a cyclic voltammogram, and the shape resembled that in the LiF-NaF-KF melt at the similar temperature. Two pairs of cathodic and anodic current peaks appeared with K2TiF6 addition in a LiCl-KCl-LiF-KF melt at 653 K in a cyclic voltammogram, and Ti metal deposited by potentiostatic electrolysis. These results show that the electrochemical reduction of Ti ion in molten salt systems is strongly affected by the composition of the bath and the operation temperature. A chloride melt including some amount of fluoride and having a lower melting point should be preferable to perform effective Ti electrolysis. In a CaF2-MgF2-CaO melt above 1300 K, some cathodic and anodic current peaks appear with TiO2 addition in a cyclic voltammogram, and the shape of the voltammogram does not change remarkably with temperature. The Ti ion in this melt seemed to be reduced to Ti metal via multi steps. From the experimental results in the CaF2-MgF2-CaO melt, the deviation in the deposition potentials between Ti and Ca is estimated at IV in a CaF2-CaO melt.

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

In order to discuss the reactivity of carbonaceous materials with CO2, the Raman spectroscopy analysis was carried out. Nine kinds of materials were examined. The Raman spectra of ordered materials could be assigned to the graphite structure and its defect, but those of disordered materials could not. New parameters were derived to evaluate the structure of the latter. Using the parameters, the structure change was followed during high temperature heat treatment. The disordered material consists of random structure, graphite structure and its defects. The random structure changes to the graphite structure with many defects and the defects decrease with the heat treatment temperature. The reaction rate constant is evaluated. It increases when the structure changes from the random structure to the graphite structure with many defects. After the change, it decreases with decreasing the defects in graphite structure. Thus, the most reactive material should consist of the graphite structure with many defects.

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Iron and Steel Institute of Japan  

In order to develop the effective way of nitrogen removal from molten steel in the electric arc furnace steelmaking, an attempt was made to accelerate the reaction by the simultaneous decarburization. The iron ore powder was blasted on to the molten steel surface with Ar carrier ggas under atmospheric pressure. The melt was 20kg. The temperature was 1850 to 1950K. The gas flow rate was 3.33 and 4.17×10-4m3/s (STP). The ore blasting rate was 0.167, 0,417 and 0.500 g/s. The results are summarized as follows
(1) By the blasting of iron ore, the decaburization occurs resulting in the acceleration of nitrogen removal several times than the mere Ar blasting. (2) Under the hard blasting condition, the nitrogen content decreased from 70 to 28 ppm for 1,000 s, while the carbon content decreased from 0.55 to 0.12 wt%. (3) When the carbon content is larger than 0.09 wt%, the decarburization was controlled by the oxygen transfer and CO bubbles are formed in the melt. When it is less than 0.09 wt%, however, the decarburization was controlled by the carbon transfer and the reaction occurs only on the melt surface. (4) It is concluded that the effective nitrogen removal is possible even under atmospheric pressure, in the ranger where the decarburization reaction is controlled by the oxygen transfer. (5) The effective interfacial area is 7 times at most as much as the cross sectional area of furnace.

DOI： 10.2355/tetsutohagane1955.90.6_414

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Iron and Steel Institute of Japan  

An attempt was made to utilize H2 for the secondary refining in steelmaking process, because H2 would react with [O] and [S] without any inclusions and accelerate the nitrogen removal from the molten steel. The 20kg of plain carbon steel was melted in the induction furnace. The gases of Ar, N2 and H2 were injected from the bottom. The temperature was ca. 1880K. The gas flow arte was 2.50 and 3.33 × 10-4m 3/s (stp). The results are summarized as follows. (1) The rate of nitrogen remove by H2 injection was 1.5 to 2.6 times larger than by Ar injection. The mechanism was (i) reduction of poisoning effect of [O], (ii) acceleration of mass transfer in the gas phase and (iii) finer bubble dispersion due to Marangoni effect. (2) The deoxidation proceeded down to 6.0 ppm by H2 injection. But this result was the sum of deoxidation by [C] and H2. Taking into account of oxygen penetration from the outside of furnace, deoxidation by H2 was evaluated. The H2 bubbles leave the molten steel far from water vapor saturation. One reason is that the deoxidation process should be controlled not only by mass transfer in the molten steel but also that in gas phase. The other reason is the shallow molten steel bath. (3) Neither desulfurization nor methane formation occurred by H 2 injection. (4) The [H] content decreased down to less than 1 ppm by Ar injection for 420 s.

DOI： 10.2355/tetsutohagane1955.90.6_422

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

The reaction rate of coke, wood charcoal and graphite with pure CO, were obtained at 1 173 and 1 373 K. The change in the reaction rate, specific surface area and micro pore size distribution with reaction degree were examined. The results are summarized as follows. (1) The specific surface area changes remarkably with reaction degree, while the reaction rate does not change so much. (2) The change in the specific surface area accords well to the change in the volume of smaller pores than 10(-8)m in diameter. (3) The reaction occurs exclusively on the surface of pores between 10(-8) to 10(-6) m in diameter. (4) The effective surface area for the reaction is from 0.064 to 0.25 of the total surface area.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TRANS TECH PUBLICATIONS LTD  

The ionic valence of Ti changed with electrorefining process of Ti in a bath equi-molar mixture of NaCl-KCl containing TiCln (n = 2 or 3); The average valence was about 2.3 initially, and became about 2.1 after electrolysis. The cathodic current efficiency was getting better with electrolysis. It should be necessary to maintain the average ionic valence lower for efficient electrolysis in the molten salt. The dominant Ti ion and its electrode reaction changed with the addition of NaF-KF in the molten salt; The average valence shifted from about 2 to about 3, and the total amount of Ti in the bath decreased. The result indicates the disproportionation reaction: 3Ti(2+) = Ti + 2Ti(3+) is induced by the fluoride addition. The quantity of electricity for Ti deposition changed consequently, and the purity of the Ti deposit was also affected.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Verlag Stahleisen GmbH  

The reaction rate per unit mass of wood char was an order of magnitude larger than that of coke and graphite and that of glassy carbon was an order of magnitude smaller than the latter. However, the reaction rate per unit surface area of wood char was smaller than that of graphite. The reaction of coke proceeded homogeneously at temperatures lower than 1373 K, while the reaction was restricted to the surface layer at higher temperatures. The tensile strength of coke after reaction decreased with the reaction degree at 1273 K, but was not changed or even increased at 1573 K. This is due to the fact that at 1573 K the core of the sample was not attacked by CO2 but strengthened by further crystallization.

DOI： 10.1002/srin.200405933

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Electrorefining of Mg has been investigated in a molten salt system, and the electrolysis conditions for the effective purification have been discussed. A purified mixture of MgCl2-NaCl-CaCl2 was used as an electrolytic bath. Magnesium metal was dissolved anodically by potentiostatic electrolysis, and purified Mg was electrodeposited at the cathode. A certain degree of cathodic overpotential was required for the effective electrodeposition of Mg metal, while large anodic overpotential directly caused the deterioration in the purity of Mg electrodeposit; it was necessary for the anodic overpotential to be less than 1.0V for good purification. In addition to the electrode potentials, some factors affected the electrorefining of Mg metal. Under the suitable electrolysis condition, the Fe content in the Mg electrodeposit was less than 10 ppm. A couple of subjects on recycling Mg metal and its alloys have been also studied: purification of Mg alloy by an electrorefining technique and distinction of Mg alloys. It was shown that pure Mg metal was electrodeposited at the cathode by the electrorefining of Mg alloy. X-ray fluorescence analysis was applied to distinction of Mg alloys, and the measuring conditions were discussed. It was concluded that the electrorefining process and X-ray fluorescence analysis were usable for the recycling of Mg metal and alloys.

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Iron and Steel Institute of Japan  

The reaction rates of Bintyo char, Bamboo char, activated carbon, coke, graphite and glassy carbon with pure CO2 have been obtained by thermo gravimetric method. After the reaction, N2 was introduced to the reaction tube to obtain the amount of adsorbed CO on the active reaction sites. The specific surface area after the reaction was measured by BET method. The results are summarized as follows: The reaction rate per unit mass were in the order of Bintyo char≒Bamboo char≒activated carbon≻graphite≒coke≻glassy carbon. The difference between the maximum and minimum were two orders of magnitude. The activation energy was 180 to 220 kJ/mol. The reaction rate per unit area of graphite, however, was an order of magnitude higher than those of Bintyo char and Bamboo char. The estimated amount of adsorbed CO was positively correlated to the reaction rate. The reaction rate constant which is independent from surface area was obtained using the reaction rate and the amount of CO adsorption, respectively per unit area. They are ranged in the order of 10-4 to 10-3 1/s. The differences among Bintyo char, Bamboo char and graphite became smaller. The enthalpy of CO adsorption was estimated as about 230 kJ/mol for Bintyo char and Bamboo char, and about 280 kJ/mol for graphite.

DOI： 10.2355/tetsutohagane1955.89.5_581

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：FREUND PUBLISHING HOUSE LTD  

In order to get a highly reactive carbonaceous material at low temperature, the reaction kinetics of various carbonaceous materials with different structure was investigated. The reaction rate was the largest for Bintyo char and bamboo char on unit mass base, but it was the largest for graphite on unit area base. The rate had a positive relation with the amount of CO adsorption, showing that the rate determining step would be the desorption of CO from the active site on the surface. The rate independent of surface area was derived from the data of the rate and amount of CO adsorption per unit area.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TRANS TECH PUBLICATIONS LTD  

Electrorefining of Mg has been investigated in a molten salt system, and the electrolysis conditions for the effective purification have been discussed. A purified mixture of MgCl2-NaCl-CaCl2 at 943K was used as an electrolytic bath. Magnesium metal was dissolved anodically by potentiostatic electrolysis, and purified Mg was electrodeposited at the cathode. The potential during electrolysis was essential for the electrolysis; large anodic overpotential directly caused the deterioration in purity of Mg electrodeposit. It was necessary for the anodic overpotential to be less than 1.0V for good purification, though a certain degree of cathodic overpotential was required for the effective electrodeposition of Mg. In addition to the electrode potentials, some factors affected the electrorefining of Mg metal. Under the suitable electrolysis condition, the Fe content of the Mg electrodeposit was less than 10ppm. The so-called "three-layer" electrolysis has been also tried in this study by using the similar experimental procedure. Magnesium metal in Mg-Cu alloy at the bottom of an electrolytic bath was dissolved anodically, and Mg metal electrodeposited at the cathode simultaneously. It is concluded that an electrorefining technique is effective for the purification of Mg metal.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TRANS TECH PUBLICATIONS LTD  

Chemical distribution of metallic elements between molten salt and liquid Mg metal has been investigated as a fundamental study on the preparation of Mg alloys by using molten salt. A purified eutectic mixture of MgCl2-NaCl-KCl was melted with Mg metal, and CaCl2, MnCl2 or LaCl3 was added to the molten salt. The contents of Na, K and Ca in Mg metal did not change remarkably even after contact with the molten salt consisting of these elements. Manganese moved from the molten salt with MnCl2 to Mg metal, and La also transferred from the molten salt with LaCl3 chemically. However, the migration of these elements were slow, and some factors should affect their chemical distributions.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

The management of radiciactivated stainless steel from a terminated nuclear reactor will become an important subject in the near future. The separation of the elements in stainless steel should be effective to reduce the management labor. In this study, the separation of the elements in stainless steel by an electrorefining technique was investigated in an aqueous solution. The electrochemical reactions of the elements in stainless steel were studied by voltammetry and potentio-static electrolysis was carried out. A stainless steel anode was dissolved electrochemically with good anodic current efficiency in a chloride solution. The residue, where Ni was concentrated, was found on the anode after electrolysis. The electrodeposit in a stainless steel cathode consisted mainly of Fe and Cr and the Ni content in it was less than 0.5wt% under suitable condition. It is concluded that an electrorefining technique is effective for the separation of the elements in stainless steel.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

In relation to the designing of a new-type blast furnace, the reaction of carbonaceous materials with CO2 is expected to occur at as low temperature as possible, In order to get a highly reactive carbonaceous material at low temperature, the reaction kinetics was investigated by measuring such quantities as the reaction rate from weight loss, the amount of CO adsorption and specific surface area by BET method. The reaction rates were large in the order of the c bar, metallurgical coke, graphite and glassy carbon. If the rate was converted to the rate per unit area, however, those of the Bintyo char was smaller than that of graphite. Thus, it is suggested that the rate of the Bintyo char is influenced by the pore diffusion Of CO2. The rate had a positive relation with the amount of CO adsorption, showing that the rate determining step would be the desorption of CO from the active side on the surface. The rate independent of surface area was derived, combining all the obtained data.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MANEY PUBLISHING  

The non-metallic inclusion content increased significantly when a steel rod of Fe-Ni was remelted by dc electroslag remelting. The silicon content increased slightly. The manganese and sulphur contents did not change. The total aluminium content in the ingot was max. 0.7%, while that in the electrode was only 10 ppm. The aluminium cations Al3+ in the slag are reduced to metallic aluminium at the slag/electrode interface, while O-2(-) anions are oxidised to dissolved (O) under bar in the metal pool. This Al and (O) under bar subsequently recombine to form alumina inclusions in the metal pool. The inclusion content was dependent on the alumina content in the slag. When a rod of plain carbon steel was remelted, however, the increase in nonmetallic inclusion content was as little as one-tenth of that for the remelted Fe-Ni rod. The non-metallic inclusion content was independent of the polarity of the electrode.

DOI： 10.1179/030192302225005132

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOCIETY INC  

Electrorefining of Mg in molten chloride has been investigated. A mixture of MgCl2, CaCl2 and NaCl was used as molten salt bath. The electrochemical behaviors of Fe, Cr and Ni were examined by voltammetry, because they are typical impurities in Mg and seriously debase Mg metal. The results being referred, the electorefining of Mg was carried out. Magnesium moved electrochemically from anode to cathode with a good cur-rent efficiency. Iron was enriched in the residual Mg metal at anode, whereas the Fe content in the Mg electrodeposit at cathode was less than that in the Mg metal supplied originally. The dependence on some electrolytic conditions being discussed, it was found that the anode potential should be essential for elimination of Fe from Mg. It was concluded that the electrorefining process was promising for purification of Mg metal.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Electrochemical behaviors of Fe, Cr and Ni have been investigated in molten salt systems as a basic study on the electrorefining of Mg metal; The electrochemical behaviors of FeCl2, NiCl2 and CrCl3 were examined by voltammetry, and the electrochemical dissolutions of these metals were also studied. A MgCl2-CaCl2-NaCl or MgCl2-NaCl-KCl melt was used as electrolytic bath. The electrode reactions of these elements were discussed on these results, and it was concluded that these elements could be eliminated from Mg metal easily by electrorefining process in molten salts. Magnesium metal was obtained electrochemically not only above the melting point of Mg metal but also below the melting point. However, Mg electrodeposit with good morphology could not be obtained under any electrolytic condition below the melting point of Mg metal.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

Electrochemical behaviors of Fe, Cr and Ni have been investigated in molten salt systems as a basic study on the electrorefining of Mg metal; The electrochemical behaviors of FeCl2, NiCl2 and CrCl3 were examined by voltammetry, and the electrochemical dissolutions of these metals were also studied. A MgCl2-CaCl2-NaCl or MgCl2-NaCl-KCl melt was used as electrolytic bath. The electrode reactions of these elements were discussed on these results, and it was concluded that these elements could be eliminated from Mg metal easily by electrorefining process in molten salts. Magnesium metal was obtained electrochemically not only above the melting point of Mg metal but also below the melting point. However, Mg electrodeposit with good morphology could not be obtained under any electrolytic condition below the melting point of Mg metal.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：INDERSCIENCE ENTERPRISES LTD  

Electroplating of Al-Ti alloy in AlCl3-BPC (n-butylpyridinium-chloride) melts containing TICln (n=2,3,4) has been studied at 300similar to450K. The cathode surface was covered with a smooth and dense metallic layer which consisted of mainly Al and included Ti. The surface became uneven with the increase in Ti content in the deposit. Intermetallic compounds of Al and Ti were not detected even in the deposit containing Ti more than 10 at%. Electrolysis in TiCln (n=2,3,4)-BPC melts has been tested above the melting point of BPC (similar to405K). Metallic electrodeposit was not obtained under any condition in these melts.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：SHANGHAI UNIV  

Some impurity elements, such as Fe, Cr and Ni are said to debase Mg metal in corrosion resistivity so that their level must keep very low for some purposes. Because primary product of Mg metal does not answer this criterion, the purification procedure of Mg metal are desired. The electrorefining process in molten salt should be promising for this purpose. In this study, electrochemical behaviors of Fe, Cr and Ni have been investigated in molten salt systems as a basic study on electrorefining of Mg metal. The mixture Of MgCl2, CaCl2 and NaCl was mainly used as molten salt bath. The electrochemical behaviors of FeCl2, CrCl3 and NiCl2 were examined by voltammetry, and the electrochemical dissolutions of these metals were examined. Potentio-static electrolysis was carried out at various electrolytic conditions, and the electrodeposit on the cathode and residue of the anode were analyzed. The results indicated that these elements could be eliminated from magnesium metal easily by electrorefining process in molten salts. Chemical distribution of elements between Mg metal and molten salts has been also examined to clarify the interaction between Mg metal and molten salts. The behaviors of main ingredients of molten salts were investigated, and those of some alloying elements were discussed.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TRANS TECH PUBLICATIONS LTD  

Electrochemical behavior of some metallic elements in molten salt systems has been investigated as a fundamental study for purification of Mg metal. A mixture of MgCl2, CaCl, and NaCl was mainly used as an electrolytic bath, and a eutectic mixture of LiCl and KCl including MgCl2 was also used. The electrochemical behavior of Li, Cr, Fe and Ni was examined by voltammetry, and their cathodic reactions were discussed. The results indicated that the electrochemical separation of the elements from Mg metal was possible in the molten salt systems. Potentio-static electrolysis was carried out below the melting point of Mg metal, and Mg metal was obtained. However, the deposit consisted of small Mg metal particle, and the surface of the particle was oxidized during rinsing with water.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：TRANS TECH PUBLICATIONS LTD  

Electrochemical behavior of some metallic elements in molten salt systems has been investigated as a fundamental study for purification of Mg metal. A mixture of MgCl2, CaCl, and NaCl was mainly used as an electrolytic bath, and a eutectic mixture of LiCl and KCl including MgCl2 was also used. The electrochemical behavior of Li, Cr, Fe and Ni was examined by voltammetry, and their cathodic reactions were discussed. The results indicated that the electrochemical separation of the elements from Mg metal was possible in the molten salt systems. Potentio-static electrolysis was carried out below the melting point of Mg metal, and Mg metal was obtained. However, the deposit consisted of small Mg metal particle, and the surface of the particle was oxidized during rinsing with water.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

Electrowinning of Ti have been investigated in a LiF-NaF-KF melt including K2TiF6 at 773-923K by applying electrochemical oxidation of H-2 gas as an anodic reaction. The cathodic behavior of titanium and the anodic behavior of H-2 gas were studied by voltammetry in detail to clarify the electrolytic condition for the process. The electrowinning of Ti was carried out by potentiostatic electrolysis. Steady electrolysis was achieved under the suitable electrolytic condition without breaking out the anode effect. Titanium metal was electrodeposited on a Ti cathode though the deposits were usually powdery. It is concluded that this process is potential if the morphology of the deposit can be improved.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

Coke plays an important role of spacer in blast furnace. However, they degenerate during Boudouard reaction. Blast furnace cokes are reacted with pure CO2 at 1072 to 1673 K. Reaction rate was obtained by the weight change of spherical specimen. The specimen after reaction was examined by microscopic observation. The reaction rate increased with temperature and was expressed by two Arrhenius type lines. The activation energy was 126 KJ/mol at higher temperature than 1373 K and 202 KJ/mol at lower temperature range. At the higher temperature range, the reaction proceeded from the surface leaving unreacted core, whereas homogeneously whole inside at lower temperature. The porosity increased from the center to surface at higher temperature, whereas it was almost constant at lower temperature.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOCIETY INC  

The electrodeposition of titanium boride and zirconium boride in a NaF-NaBF4 eutectic melt have been studied. The voltammetric measurements showed that Ti ions were reduced electrochemically to di-valent by two steps. A flat and adhesive TiB2 layer up to 50 mu m was obtained by potentio-static electrolysis under a proper condition, though no cathodic current peak for TiB2 deposition was detected in the voltammograms. A cathodic current peak corresponding to reduction of Zr ion was observed in a NaF-NaBF4-K2ZrF6 melt, but ZrB2 was not obtained under any electrolytic condition. The electrode behavior of B and Zr ions in a LiF-KF-NaF melt was different from those in a NaF-NaBF4 melt, and ZrB2 was electrodeposited in a LiF-KF-NaF-NaBF4-K2ZrF6 melt. These results indicate that the deposition of TiB2 in a NaF-NaBF4 system was not a simple electrode reaction but a sequence of electrochemical and chemical reactions.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOCIETY INC  

Direct electrowinning of liquid titanium metal has been investigated by using a DC-ESR (Direct Current Electro-Slag Remelting) apparatus. A graphite rod was used as anode and a metal base-plate was used as cathode. A metal pool was formed on the base-plate with the small distance between the cathode and the anode, though the current efficiency got worse when the distance was too small. Pure titanium metal pieces were obtained in the solidified slag after the run with the bigger distance. It is concluded that Ti is able to be electrowon by the present process and that the formation of a larger metal pool on the base-plate with the bigger distance between the electrode was essential to efficient electrolysis.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：ELECTROCHEMICAL SOCIETY INC  

The electrodeposition of titanium boride and zirconium boride in a NaF-NaBF4 eutectic melt have been studied. The voltammetric measurements showed that Ti ions were reduced electrochemically to di-valent by two steps. A flat and adhesive TiB2 layer up to 50 mu m was obtained by potentio-static electrolysis under a proper condition, though no cathodic current peak for TiB2 deposition was detected in the voltammograms. A cathodic current peak corresponding to reduction of Zr ion was observed in a NaF-NaBF4-K2ZrF6 melt, but ZrB2 was not obtained under any electrolytic condition. The electrode behavior of B and Zr ions in a LiF-KF-NaF melt was different from those in a NaF-NaBF4 melt, and ZrB2 was electrodeposited in a LiF-KF-NaF-NaBF4-K2ZrF6 melt. These results indicate that the deposition of TiB2 in a NaF-NaBF4 system was not a simple electrode reaction but a sequence of electrochemical and chemical reactions.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELECTROCHEMICAL SOC JAPAN  

Direct electrowinning of liquid titanium metal has been investigated by using a DC-ESR (Direct Current Electro Slag Remelting) apparatus. A small scale DC-ESR unit was operated in a DC reverse polarity mode, where a graphite rod tvas used as anode and a steel or a copper base-plate was used as cathode. The used salt was CaO-CaF2-TiO2 mixture. The distance between the cathode and the anode was essential to the electrolysis. A metal pool was formed on the base-plate and the current efficiency for the reduction was up to 18 % with the proper distance between the electrodes. Some amount of titanium was electrodeposited on the base-plate though its state changed with the electrolytic condition. Pure titanium metal pieces were obtained in the solidified salt after the run with the bigger distance. It is concluded that the electrowinning of liquid titanium metal by the present process is possible if sufficient heat to form a metal pool can be supplied at the bigger distance between the electrodes.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

In the previous work, a new method to identify the shape of an inclusion was developed with the aid of image processing equipment. An attempt has been made to characterize inclusions in stainless steel using the method. Classifying areas for circles, triangles, squares, bars and intricates has been determined more accurately on two dimensional chart of y=L-2/(4A pi) and X=pi D-2/(4A). The inclusions were relieved on the surface of specimen by electrolytic etching with the SPEED technique. By these improvements, the inclusions with triangular, square, bar and intricate shape, as well as circular inclusions, were clearly classified. However, it seemed difficult to identify the chemical species of inclusion from its shape in the case of specimen from molten steel and CC slab. In the case of rolled sheet, the inclusions with different shape could be identified respectively. Therefore, the image processing of inclusions coupled with relieving of them by electrolytic etching might be one of the hopeful ways to characterize the inclusions in rolled sheet of stainless steel.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPAN INST METALS  

TiB2-coated metal should be a very promising material for many purposes. One of the hardest problems on TiB2 coating is to prevent necking or stripping by thermal expansion gap between TiB2 deposit and substrate. In this study, we have investigated the electroplating of TiB2 in NaF-NaBF4 eutectic melt(m.p.657K) with Na2TiF6 or TiF3. The constant-potential electrolysis was carried out at various potentials. The electrodeposit was obtained at more negative potential than that of reduction of Ti(III) to Ti(II). The result of EPMA and XRD showed that the main ingredient of electrodeposit was TiB2. The morphology of electrodeposit changed remarkably at the potential where the cathodic current began to increase sharply in a voltammogram. The flat and adhesive deposit was obtained at more positive potential, while the electrodeposit became powdery at more negative potential. The morphology also changed with time, that is, the protuberant deposit grew with the current increase after a certain time even at the potential where the flat deposit was expected. The monitoring of current was important for depositing the thick and flat layer in this process, and the layer up to 50 mu m was obtained under suitable conditions, The dependence of the morphology on Ti ion concentration or substrate was not critical in this process.

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Institute of Metals (JIM)  

Exfoliation corrosion proceeds laterally along planes parallel to the surface of high strength aluminum alloys. The ASTM G34 (EXCO) test is widely used to predict exfoliation corrosion susceptibility. The susceptibility is determined by visual examination in which the surface profile is compared with the reference standard photograph. This method is ambiguous, so that it is difficult to distinguish general corrosion (overall corrosion, pitting) from exfoliation. In this study, a quantitative estimation method of exfoliation corrosion susceptibility based on ASTM G34 was developed, and the effect of composition and heat treatment of the alloys on exfoliation corrosion susceptibility were examined by this method. The specimens used were of 7XXX, Al-Li series alloys treated in T6, T7 and T4 modes. The normal procedure of ASTM G34 was carried out. Moreover, as quantitative measurements, the mass losses and quantity of exfoliation were evaluated by the following procedure. The specimens were soaked in nitric acid for 2 min and rinsed in water after being rated. After drying for about 30 min, the mass losses were measured. One week later, piles on the specimens were removed from the surface by a tooth brush. The piles and residues in solution were treated with hydrochloric acid, so that the weight of the metallic component was estimated by the amount of evolved hydrogen gases. The quantity of exfoliation was defined by the weight. The results obtained in this study were as follows
(1) The quantity of exfoliation was slightly correlated with ASTM G34 rating. The exfoliation corrosion could be distigushed from the overall corrosion and pitting. (2) Exfoliation susceptibility was especially high in the alloys containing from 0.7 to 1.0%Cu. The alloy containing 0.37%Cu was the lowest. (3) The heat treatment in T7 gave high susceptibility of exfoliation corrosion, while that in T4 gave high susceptibility of overall corrosion and pitting.

DOI： 10.2320/jinstmet1952.60.12_1187

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Selective extraction of uranium from a phosphate ore was studied by using the mixed gas of Cl2 and O2. On heating the ore and carbon mixture in Cl2, the volatilized chloride of uranium is accompanied by iron, aluminum, phosphorus and silicon chlorides. The addition of O2 gas effectively lowered the volatilization ratios of aluminum, phosphorus and silicon. The ratio decreased with increasing oxygen flow rate up to 50ml/min at 1,223 K (Cl2: 100ml/min, O2+N2: 400m//min). The volatilization ratio of uranium was almost unchanged at 90% up to 50 ml/min O2 (carbon amount: 15wt%). The effect of the other parameters, i.e. Cl2 flow rate, carbon amount, reaction temperature and time was examined. © 1996 Taylor and Francis Group, LLC.

DOI： 10.1080/18811248.1996.9731912

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Selective extraction of uranium from a phosphate ore was studied by using the mixed gas of Cl2 and O2. On heating the ore and carbon mixture in Cl2, the volatilized chloride of uranium is accompanied by iron, aluminum, phosphorus and silicon chlorides. The addition of O2 gas effectively lowered the volatilization ratios of aluminum, phosphorus and silicon. The ratio decreased with increasing oxygen flow rate up to 50ml/min at 1,223 K (Cl2: 100ml/min, O2+N2: 400m//min). The volatilization ratio of uranium was almost unchanged at 90% up to 50 ml/min O2 (carbon amount: 15wt%). The effect of the other parameters, i.e. Cl2 flow rate, carbon amount, reaction temperature and time was examined. © 1996 Taylor and Francis Group, LLC.

DOI： 10.1080/18811248.1996.9731912

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

A thermodynamical and pyrometallurgical study to recover uranium from the phosphate ores was undertaken using the chloride volatilization method. Iron was chlorinated with solid chlorinating agents such as NaC1 and CaCl2 in combination with activated carbon, which will be used for removing this element from the ore, but uranium was not. On the other hand, the chlorination using Cl2 gas and activated carbon gave a good result at 1,223 K. Not only uranium but also iron, phosphorus, aluminum and silicon were found to form volatile chlorides which vaporized out of the ore, while calcium remained in the ore as non-volatile CaCl2. The chlorination condition was studied as functions of temperature, reaction time and carbon content. The volatilization ratio of uranium around 95% was obtained by heating the mixture of the ore and activated carbon (35 wt%) in a mixed gas flow of Cl2 (200 ml/min) and N2 (200 ml/min) at 1,223 K for 120 min. © 1995 Taylor and Francis Group, LLC.

DOI： 10.1080/18811248.1995.9731789

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：MINERALS, METALS & MATERIALS SOC  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP PUBLISHING LTD  

The potassium-indium system has been studied using galvanic cells with potassium beta alumina as the electrolyte. The thermodynamic properties of the liquid solution have been determined between 0 and 52 at.% potassium. There is some evidence for a very weak liquid compound near 35 at.% K, but not at 50 at.% K. Changes are proposed for the potassium-indium phase diagram, including the liquidus temperature and the existence of new compounds.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

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記述言語：英語   出版者・発行元：ELECTROCHEMICAL SOC INC  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELECTROCHEMICAL SOC JAPAN  

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