巻号一覧
52 巻, 3 号
選択された号の論文の16件中1～16を表示しています
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永山 勝久, 井野 博満, 白鳥 紀一, 斉藤 直昭, 中川 康昭, 喜多 英治1988 年 52 巻 3 号 p. 251-258
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーSingle amorphous phase was obtained in Fe1−xNdx alloys by melt-spinning in a composition range of 0.11≤x≤0.60. Magnetization and Mössbauer effect were measured for these alloys.
The internal magnetic field of 57Fe nuclei is about 2.4 MA/m(300 kOe) at 77 K, being independent of composition. It suggests that the average magnetic moment of Fe atoms is nearly constant: \barμFe\simeq2.0 μB/atom. On the contrary, the average magnetic moment of Nd atoms, calculated from the results of the magnetization measurements and the above estimation of \barμFe, decreases with increasing Nd concentration: \barμNd=3.2 μB/atom at x=0.15, which agrees with the free Nd3+ ion moment of 3.3 μB/atom and \barμNd=1.6 μB/atom at x≥0.40. While the coercive field, Hc, at 4.2 K is about 160 kA/m(2 kOe) for x=0.20, it increases abruptly for x>0.25 and becomes 5.6 MA/m(70 kOe) for x=0.55. These results can be explained by large random magnetic anisotropy of Nd atom in the amorphous alloys.抄録全体を表示PDF形式でダウンロード (1095K) -
原勢 二郎, 清水 亮, 高嶋 邦秀1988 年 52 巻 3 号 p. 259-266
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーIn an attempt to clarify the mechanism of secondary recrystallization in 3%Si-Fe, the orientation relationship between the secondary Goss grains and the matrix texture and the Goss nucleus in the primary texture was investigated utillizing X-ray (vector method) and SEM-ECC-ECP technique. The main results obtained are as follows.
(1) The largest grain present in the surface of primary recrystallized specimen was not a Goss oriented grain and the frequency peak of Goss oriented grains deviated about 0.035 rad from the rolling direction when processed by the one-stage cold rolling method. The intensity peak of Goss grains was situated within 0.087 rad from the rolling direction when processed by the two-stage cold rolling method.
(2) The frequency distribution of Σ9 coincidence grains corresponding to Goss grains rotated about ND axis has a peak value at an ideal Goss orientation in the primary matrix processed by the one-stage cold rolling method, while no peak value was recognized at the ideal Goss orientation when processed by the two-stage cold rolling method.
(3) The frequency distribution of Goss secondaries has a peak value at an ideal Goss orientation. However, in the two-stage cold rolling process, a peak value is situated between 0.09 and 0.18 rad apart from an ideal Goss orientation.
(4) It can be concluded from the above findings that the distribution of coincidence boundaries rather than the size and the frequency of Goss grains in the primary texture mainly determines the sharpness of Goss secondaries in the grain oriented silicon steel processed both by the one- and two-stage cold rolling methods.抄録全体を表示PDF形式でダウンロード (1323K) -
古屋 泰文, 島田 平八, 荒砥 孝二1988 年 52 巻 3 号 p. 267-271
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーAdvanced magnetic non-destructive measurement technique, the “Barkhausen noise (BHN) analysis” method, is employed for the material evaluation of the spheroidal graphite cast iron. BHN signal is detected by a contact type sensor setted on the surface of plate specimen and analyzed by a digital spectrum analyzer. It is experimentally confirmed that (1) BHN generating power(PWA) depends on the graphite content (i.e.area fraction of graphite, FA) of the material and (2) average spheroidal graphite size (i.e.diameter \barr) can be estimated by a parameter of normalized BHN spectrum peak height (Hp). Moreover, combining brinell hardness (HB) with BHN signal, some correlation can be obtained between mechanical tensile strength (σUTS) and a parameter φ=(PWA)×(hardness, HB).
In consequence, the BHN method is also applicable for the non-destructive material evaluation of graphite cast iron and useful information about material properties seems to be obtained by this method.抄録全体を表示PDF形式でダウンロード (592K) -
長岡 邦夫, 那須 稔雄, 砂野 豊治朗, 池田 圭介1988 年 52 巻 3 号 p. 272-278
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーStress corrosion cracking (SCC) processes of 7475 aluminium alloy in 3%NaCl aqueous solution at constant temperature, 348 K, under several degrees of strain were recorded using a time-lapse video tape recorder (VTR). The strain were loaded to the sample by the bending method. The crack initiation time, relationship between crack length and time, SCC propagation velocity, SCC initiation point and type of crack propagation route were analyzed by observing the VTR images.
The effect of hydrogen charging on mechanical properties of 7475 alloy by cathode charge method was studied, and the relation between SCC and hydrogen was discussed.
The crack initiation time of SCC became shorter with increasing strain. The propagation velocity was increased with increasing strain. The crack initiation points were not distributed only in the front area of notch but also in the active area of corrosion. The ductility of 7475 alloy was decreased by hydrogen charging. The crack initiation points and the propagation routes of SCC in this alloy were sorted into four types. However, the propagation velocities were almost the same in these four types, suggesting analogous mechanisms of crack propagation. The hydrogen embrittlement and reaction of anodic dissolution were deemed to be related to the SCC propagation of this alloy.抄録全体を表示PDF形式でダウンロード (1665K) -
下尾 聰夫, 水滝 房吾, 安藤 繁, 木村 弘1988 年 52 巻 3 号 p. 279-287
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe rates of the reactions of the gaseous species SiO and CO with solid carbon have been studied by means of thermogravimetry at temperatures between 1673 and 1973 K, in order to investigate the mechanism of the formation of SiC in SiO2-C mixtures. The graphite substratum has been allowed to react with SiO and CO generated from the heated SiO2-C mixture.
At lower temperatures, the deposit of SiC is formed on the graphite substratum by the over-all reaction
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The formation of SiC is linear with the reaction time. The activation energy is 97 kJ/mol. It is considered that the rate of the formation would be under a mixed control of the interfacial reaction and the gaseous diffusion. At 1873 K and higher, SiC is formed by the over-all reaction
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The layer of SiC grows into the graphite and the rate of the formation of SiC obeys the parabolic rate equation. The activation energy is 524 kJ/mol. The rate-determining step is the diffusion of carbon in SiC.抄録全体を表示PDF形式でダウンロード (2801K) -
沼田 博雄, 平能 康雄, 春山 志郎1988 年 52 巻 3 号 p. 288-294
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーCorrosion of iron in alkali-sulfate melt containing Fe2(SO4)3 has been studied with electrochemical polarization technique. The corrosion rate of iron increased with increasing the concentrations of ferric ion below 10 mol%. The polarization curves of iron consisted of the anodic dissolution of iron and the cathodic reduction of ferric ion in the potential region from 0.3 to −0.5 V. Polarization study showed that the corrosion reaction was controlled by a diffusion-limited cathodic reduction of ferric ion and the rate of corrosion was proportional to the concentration of ferric ion. It was found that the cathodic reaction was also promoted by the corrosion product such as ferrous ion which was chemically oxidized and functioned as an oxidant. Thus, the corrosion of iron in molten sulfate was explained by an auto-catalytic mechanism of the corrosion product.抄録全体を表示PDF形式でダウンロード (888K) -
沼田 博雄, 門馬 昭彦, 浅子 喜一郎, 春山 志郎1988 年 52 巻 3 号 p. 295-302
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe kinetics of the O2−/1/2O2 on Pt, Au and Pd electlodes in NaCl-KCl melt at 1023 K have been studied with the galvanostatic double pulse and a.c. impedance methods. The cathodic polarization curves on these electrodes under different partial pressures of oxygen exhibited a diffusion limited current and the cathodic reduction of oxygen proceeds via a two-step mechanism. The rate of the rapid charge transfer step measured with the galvanostatic double pulse method was of the order of 104 A·m−2. Cole-Cole plot of the impedance of the oxygen electrode exhibited a semicircle at high frequencies and a Warburg behavior at low frequencies. The exchange current obtained from the diameter of the semicircle was two orders of magnitude less than that obtained from the galvanostatic double pulse method and probably corresponds to that of the slower reaction step.抄録全体を表示PDF形式でダウンロード (964K) -
神谷 昌哉, 芝田 隼次, 佐野 誠, 西村 山治1988 年 52 巻 3 号 p. 303-309
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーExtraction of metal ions from the aqueous phase containing non-aqueous solvents such as dimethyl formamide (DMF), dimethyl sulfoxide (DMSO) and acetonitrile (AN) was investigated by using di-2-ethylhexylphosphoric acid (D2EHPA) as an extractant. The organic phase was a binary solution of D2EHPA and n-hexane, or D2EHPA and toluene, while the aqueous phase was a three-component solution of metal salt, non-aqueous solvent and water. Metal ions used for this purpose were Cr(III), Fe(III), Al, Cu, Ni, Co, Mg and Ag.
The extraction of metal ions is strongly affected by the addition of non-aqueous solvent. The effect is dependent on the kinds of non-aqueous solvent, the amounts of non-aqueous solvent and the kinds of metal ion. The extraction behavior in the presence of non-aqueous solvents are classified into the following three groups: (1) extraction of Cu, Ni and Co increases by adding DMSO and DMF less than 50 vol% and then decreases by the addition more than 50 vol%, (2) extraction of Ag, Cr and Fe decreases with an increasing addition of DMSO and DMF, irrespective of its amount and (3) extraction of Mg and Al increases with an increasing addition of DMSO and DMF, regardless of its amount. The addition of AN does not cause a great change in the extraction of metal ions except Al and Ag, but the extraction of Ag is remarkably decreased by the addition of AN. The above extraction behavior may be explained by the complexing ability of non-aqueous solvents, the increase in the distribution amount of the extractant and extract in the aqueous phase, and the interaction between the extractant and non-aqueous solvents in the organic phase due to the dissolution of non-aqueous solvents in the organic phase.抄録全体を表示PDF形式でダウンロード (892K) -
武津 典彦, 栗田 典明, 大橋 照男1988 年 52 巻 3 号 p. 310-319
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーIn order to make clear the conduction mechanism of a new type proton conductive solid electrolyte SrCe0.95Yb0.05O3−δ, DC-polarization characteristics of a hydrogen concentration cell based on this electrolyte were investigated in the temperature range 973-1123 K. The cell was designed to have asymmetrical electrodes; one was reversible for both oxygen and hydrogen, and the other was irreversible for hydrogen. By polarization, only the movement of proton was blocked and the steady-state current due to the sum of the oxygen ion and the positive hole was measured. The current resulted from the migration of oxygen ion was separated from it by measuring the mass of transported oxygen with the volumetric method. Observed oxygen ion and positive hole currents were both negatively dependant on the hydrogen potentials of the reversible electrode. With increasing applied voltage, these currents increase exponentially in the small potential region and linearly in the high potential region. From a comparison between the theoretically derived and the observed voltage-current relationships, the conduction mechanism was examined and the parameters controlling the imperfection equilibria and the value of carrier mobilities were estimated. Based on these values, the partial conductivities and transport numbers of positive hole and oxygen vacancy were evaluated. In the electrolyte equilibrated with air containing 1% water vapour, the transport numbers of positive hole and oxygen vacancy were found to be in the range 0.2-0.6 and 0.01-0.15, respectively. They were found to increase with the temperature and decrease with the hydrogen partial pressure.抄録全体を表示PDF形式でダウンロード (1198K) -
横田 憲克, 下屋敷 重広1988 年 52 巻 3 号 p. 320-326
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーDeposition of corrosion products have been studied in a thermally convective sodium, using a sodium pot constructed of Type 304 stainless steel with a temperature range between 833 and 943 K. Deposited particles on the deposition test pieces were analyzed for their shapes and chemical compostions.
The deposited particles were classified into the following three types: (a) a polyhedral shape with a large content of iron, (b) a hexagonal plate shape with a large content of chromium, and (c) a shape without particular form having a similar composition to that of Type 304 stainless steel but with lesser chromium. The compositions of (a) and (c) were along precipitation lines of the Fe-Cr-Ni ternary phase diagram at 833 K. Hence, the elements, Fe, Cr and Ni, which were released into the sodium deposited to form particles having the chemical composition along the precipitation lines.
The size of the polyhedral particle was 3 μm. It seemed that, when the polyhedral particles grew larger than 3 μm, the crystal growth occurred along (100) and (110) planes to form a chain particle. The size of hexagonal plate particle was 0.3 μm. The particle size distribution of all the three shapes showed an average diameter of 4 μm and a standard deviation of 2 in a logarithmic normal distribution.抄録全体を表示PDF形式でダウンロード (1571K) -
秋山 哲也, 寺崎 敏夫1988 年 52 巻 3 号 p. 327-335
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe conditions needed for the model to predict the sensitization and the LTS of type 304 stainless steel were investigated by the measurements of the incubation period in the sensitization.
To measure the incubation periods, EPR test was used.
In isothermal heat treatment, the incubation period was observed. But in isothermal heat treatment following the heat treatment at 1113 K for 700 s, the incubation period was not observed. Reactivation ratio Ra was increased as follows.
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where t is the time for isothermal heat treatment and α is the constant.
It means that the sensitization can be described as the one-dimension diffusion theory.抄録全体を表示PDF形式でダウンロード (1757K) -
増田 正孝, 田中 良和, 渡辺 康裕, 七尾 進, 望月 隆1988 年 52 巻 3 号 p. 336-342
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーRapidly Quenched aluminum-titanium alloys provide excellent characteristics as electrodes for electrolytic capacitors, since anodic oxide films formed on them have large dielectric constants and high breakdown voltages. Structure of the oxide films was analyzed by the use of TEM, EDX and X-ray diffraction techniques. The results obtained are as follows; (1) The structure of anodic oxide films is always amorphous. (2) Boiling water pre-treatment produces fibrous structure on the film surface. (3) The thickness of oxide per unit formation voltage is 1.3-1.4 nm/V. (4) Titanium rich petal-like oxide flakes exist in the oxide, and this is the cause of the excellent properties of this new electrode material.抄録全体を表示PDF形式でダウンロード (2408K) -
林 宏爾, 木原 宏1988 年 52 巻 3 号 p. 343-347
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe green compact from Fe ultrafide powder (average particle size, 0.02 μm; oxygen content, 15 mass%) was pressure-sintered under 100 and 200 MPa at 673∼973 K for 1.8 ks in flowing hydrogen, after the reduction of the iron oxide. The densification temperature, crystal grain size and hardness of the compact were investigated, in comparison with those in the case of pressureless-sintering.
The results obtained were as follows; (1) The nearly full densification temperature under 100 and 200 MPa were lower by about 150 K and above 300 K respectively than that (970 K) in the pressureless-sintering. (2) The minimum value of the average grain size in the dense pressure-sintered compact was about 0.15 μm, which was much smaller than 1.2 μm of the pressureless-sintered compact. (3) The hardness of the pressure-sintered compact with the grain size of 0.15 μm was as high as about 385 HV, compared with about 85 HV of the usual coarse-grained iron metal. The Hall-Petch linear relationship between HV and the square root of the grain size was confirmed to hold also for the grain size range larger than about 0.15 μm.抄録全体を表示PDF形式でダウンロード (879K) -
鴨田 秀一, 酒井 昌宏, 田頭 孝介, 五十嵐 正, 赤沼 正信1988 年 52 巻 3 号 p. 348-354
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーA new method for the bonding of metals is proposed. The method includes thermal spray coatings of a self-fluxing alloy on the bonding surfaces. The bonding of mild steels, which had been spray-coated with nickel base alloy powders, was attempted at 1253-1333 K for 60 s-10.8 ks mainly in Ar gas without any bonding pressure except the dead load of test pieces themselves. The bonding region showed satisfactory metallographic structures, but only a few pores were observed. The tensile strength of the bonded joints was over 310 MPa for an optimum bonding condition. The similar tensile strength was also obtained in the bonding atmospheres of the air and a vacuum (1.33×10−2 Pa) as well as in Ar gas. Fractures occurred mostly in the diffusion zone in the bonding region where small voids were located. It is assumed that these voids might be the unbonded spots at the initial interface between the mild steel and the spray coatings.抄録全体を表示PDF形式でダウンロード (1995K) -
森 信幸, 本郷 晴, 大城 桂作1988 年 52 巻 3 号 p. 355-362
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe wettability and the interaction between liquid Sn or Sn-Cu alloys and solid Cu-Nb two-phase alloys, which are in use to make in-situ Cu-Nb3Sn superconducting composites, were investigated by the sessile drop method in vacuum at temperatures from 523 to 903 K.
Wetting angle of liquid Sn or Sn-Cu alloys to solid pure Nb, Cu-30%Nb, 8%Nb alloys, or pure Cu substrate was affected by the wetting temperature, time, composition of solid Cu-Nb substrate or liquid Sn alloy, and additional element of Ti. Especially, in spite of a significant reaction of substrate with Sn, the fraction of Nb and the Cu phase in solid substrate was considered as a controlling factor in wetting behavior of liquid Sn or Sn alloy, and Cassie’s equation of wetting angle for the composite surface of the Cu and Nb phases could be applied approximately. The variations in the composition and thickness of the interfacial reaction zone were clarified up to 6 h at temperatures of 643, 823, and 873 K by using solid-liquid diffusion couple type specimens.抄録全体を表示PDF形式でダウンロード (1889K) -
大島 聡範, 林 忠夫, 高橋 忠義1988 年 52 巻 3 号 p. 363-368
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe effects of small casting defects on the fatigue properties of medium carbon cast steel are studied using sample block cut from continuously cast steel bloom.
A series of variously defective specimens cut and machined from the single block are subjected to tensile, fatigue and fatigue crack growth tests. Some other specimens cut and machined from another hexahedrally forged block are also tested, in which defects are pressure welded to be almost removed without change in dendritic morphology.
The results are summarized as follows.
(1) Fatigue crack growth rate of defective cast steel is little affected by the defectivity and dendritic morphology.
(2) Fatigue properties of defective cast steel are almost governed by the magnitude of initial stress intensity factor of the defect from which fatigue crack originates.
(3) In defective cast steel, fatigue limit σW is closely related with the tensile fracture strain εf as well as the tensile strength σB. Therefore, σw is successfully correlated with the parameter σB\sqrtεf.抄録全体を表示PDF形式でダウンロード (1100K)
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