巻号一覧
38 巻, 5 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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小松 登, 大林幹男 , 遠藤 淳二1974 年 38 巻 5 号 p. 379-385
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe authors studied a powder boronizing process which uses ferroboron as boron source and provides steels with a wear- and corrosion-resistant layer. For the purpose of obtaining a uniform, dense and thick boride layer, effects of the processing condition were investigated, particularly in regard to the effect of Al content in ferroboron and the additive materials. The results were as follows.
(1) No boride layer was formed on the steel specimens which were packed in ferroboron powders and heated at 1000°C for 5 hr in H2 atmosphere. Aluminum and silicon in the ferroboron preferentially produced solid solution consisting of Fe, Al and Si.
(2) When alkali-metal carbonate such as Li2CO3, Na2CO3 or K2CO3 was added to the ferroboron, the aluminizing effect was inhibited and a dense boride layer was formed. The thickness of the boride layer tended to increase as the melting point of an added material became lower and the dissociation pressure became higher.
(3) The boride layer produced by the ferroboron and alkali-metal carbonate method was different from those produced using the method of electrolysis in the molten salts and the gas method. The layer consisted mainly of Fe2B, with a small amount of FeB. The hardness of the boride layer was Hv 1300∼1800.
(4) The optimum condition to obtain the boride layer for practical applications was: (a) Al content in ferroboron: below about 4%, (b) alkali-metal carbonate content in ferroboron: about 10%, and (c) boronizing temperature: about 1000°C.抄録全体を表示PDF形式でダウンロード (1078K) -
平野 敏幸, 山口 正治, 三崎 晴夫, 山根 寿己1974 年 38 巻 5 号 p. 385-390
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーTensile tests of Fe-Cr and Fe-Ni alloys have been carried out in the ferrite, ferrite+austenite, and austenite regions over a range of strain rates 10−4 to 10−1 min−1. Fe-Cr alloy have shown the typical superplastic behaviour in the two-phase region at the strain rates lower than 3×10−4 min−1. The role of the two-phase structure in the superplastic behaviour of these alloys has been discussed. The results obtained are as follows:
(1) The minimum in flow stress of Fe-Cr and Fe-Ni alloys was observed in the ferrite+austenite two-phase region.
(2) For both alloys, the maximum in strain rate sensitivity, m, is observed in the two-phase region.
(3) A good correlation was found between m-value and elongation in Fe-Cr alloys. The maximum elongation is obtained in the two-phase region where the m-value is largest.抄録全体を表示PDF形式でダウンロード (768K) -
高橋 仙之助1974 年 38 巻 5 号 p. 390-394
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe experiments were carried out to study how the minimum creep rate of Ni-Al solid solution alloys depends on stress and temperature at temperatures of 600∼750°C and a stress of 2∼5 kg/mm2. The minimum creep rate \dotε can be well expressed by the equation
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and the values of A, n and Q were obtained. Here σ is the applied stress, A the frequency factor, Q the activation energy, R the gas constant and T the absolute temperature. The apparent activation energies and n values for the Ni-2.1 at%Al alloy and Ni-6.0 at%Al alloy were 65.5(0.93) kcal/mol, 5.9(0.65) and 59.3(0.81) kcal/mol, 5.3(0.79), respectively (the values in parentheses express the standard deviations). The calculated A values were 1.9×109(0.35×109) for Ni-2.1%Al and 5.6×106(1.3×106) for Ni-6.0%Al alloy under the constant applied stress.抄録全体を表示PDF形式でダウンロード (462K) -
井ノ山 直哉, 川野 豊1974 年 38 巻 5 号 p. 394-401
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe authors have investigated the retarding effect of nitrogen on the graphitization of white cast iron.
In agreement with some other investigators, the results showed that acid-soluble nitrogen (NS) retarded the first stage graphitization more severely than acid-insoluble nitrogen (NI) in white cast iron. Moreover, it was deduced that of the acid-soluble nitrogen, the solid soluted one in cementite of white cast iron would retard the decomposition of cementite as a result of strengthening the bonding of cementite.
In this paper, the retarding mechanism of nitrogen on graphitization was investigated thermodynamic alloy in connection with the distribution of the nitrogen during the solidification process of molten iron and also during the malleablized annealing process of white cast iron.
The main results obtained are summarized as follows:
(1) In the case of supersaturation of nitrogen over the equilibrium solubility in molten cast iron, the nitrogen tends to be condensed in eutectic cementite.
(2) The first stage graphitization is retarded in proportion to the concentration of the nitrogen in cementite.
(3) In the course of the first stage graphitization, a part of nitrogen diffuses through the specimen into argon gas atmosphere, and the acid-soluble nitrogen in austenite decreases.
(4) Most of the remaining nitrogen is dissolved in austenite. The more nitrogen is dissolved in austinite, the more it becomes to involve in the eutectoid cementite.
(5) The second stage graphitization is retarded in proportion to the concentration of the solute nitrogen in the eutectoid cementite.
(6) After the second stage graphitization, most of nitrogen is changed to stable silicon nitride, and the NS content in ferrite is less than 16 ppm.抄録全体を表示PDF形式でダウンロード (753K) -
信木 稔, 小口 醇1974 年 38 巻 5 号 p. 401-407
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe increase in ductility under high hydrostatic pressure was investigated using quenched and tempered specimens of a carbon steel containing about 0.45%C.
The tensile tests were carried out at hydrostatic pressures up to 12000 kg/cm2 and at atmospheric pressure at room temperature. The tests during which the ambient pressure was released from 12000 kg/cm2 to atmospheric pressure were also done.
The results obtained are as follows: (1) When the specimens are tempered to be in a hardness range where they are ductile at atmospheric pressure, both the fracture strain and the fracture stress increase linearly with increasing ambient pressure. (2) The voids generated around inclusion particles at a strain given under high hydrostatic pressure are smaller than those at the same strain given at atmospheric pressure. That is, the growth of voids is suppressed under high hydrostatic pressure. (3) When the specimen having the hardness of HRC 56.5 is prestrained to varisus strains up to about 0.9 under 12000 kg/cm2, surplus ductility is observed atmospheric pressure. In this range of prestrain the fracture stress at atmospheric pressure increases with prestrain unde 12000 kg/cm2, but when the amount of prestrain under 12000 kg/cm2 is beyond 0.9, the surplus ductility disappears and the fracture stress decreases abruptly. (4) From the results (2) and (3), the increase of ductility due to the high hydrostatic pressure is considered to be attributed to the facts that the pressure suppresses the growth of defects such as voids and cracks and the fracture is delayed until a stress condition for fracture is satisfied. The specimen deformed under pressure, however, has more defects than that deformed at atmospheric pressure.抄録全体を表示PDF形式でダウンロード (992K) -
淀川 正進1974 年 38 巻 5 号 p. 408-415
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe microstructural changes during aging in age-hardenable Fe-Ni-Mn martensitic alloys have been studied by means of electron microscopic observation and electron diffraction. The results obtained in this study are summarized as follows.
(1) The quenched structure before aging is lath martensite containing a high density of dislocations.
(2) In the early stage of aging, very fine zones with high solute concentration are homogeneously formed all over the specimen due to the two-phase decomposition.
(3) Subsequently the zone acts as a nuclei of the fct NiMn phase. As the zone changes to the fct NiMn particle the hardness increases up to the maximum value. The main cause of age-hardening is considered to be a strain hardening due to the coherency strain between zone or NiMn particle and matrix.
(4) In the overaging and softening processes, the NiMn particles grow into disc-like platelets on the (100) planes of matrix, and the crystallographic orientation relationship with respect to the matrix is determined to be (011)α′4°(111)NiMn, [\bar1\bar11]α′8°[\bar101]NiMn.
(5) The final equilibrium stable structure is microduplex lamellae consisting of austenite and ferrite (or martensite) grains and the NiMn phases disappear. Both the austenite and ferrite phases have the K-S relationship with each other.抄録全体を表示PDF形式でダウンロード (1153K) -
辻 新次, 山中 久彦1974 年 38 巻 5 号 p. 415-421
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーInterdiffusion in the Cu-Fe system was studied in the temperature range between 860∼1010°C, using diffusion couples of pure metals.
The interdiffusion coefficients \ ildeD in the Cu, γ-Fe and α-Fe phases of the Cu-Fe system were determined by the Matano method and also by a method which was based on a graphical evaluation of the relative amounts of transfer of both component atoms through a phase interface.
The results obtained by these two methods are in good agreement for the γFe and αFe phases. However, the activation energy \ ildeQ and the frequency factor \ ildeD0 for interdiffusion in the Cu phase obtained by the present method differed clearly from those obtained by the Matano method. The difference was due to the concentration dependence of \ ildeD and to the temperature dependence of the solubility limit of Fe in the Cu phase. An exact consistency was seen between the moving rate constants of phase interfaces determined from concentration-distance curves and the ones calculated by an iterative approximation from the characteristic values of the system.抄録全体を表示PDF形式でダウンロード (576K) -
松島 志延, 石原 只雄1974 年 38 巻 5 号 p. 421-426
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe effect of 0∼1.5% nickel in conjunction with other impurities such as phosphorus, carbon, manganese, silicon and nitrogen on stress corrosion cracking of 18Cr ferritic stainless steels was tested in boiling 42% magnesium chloride solution by using U-bend specimens.
Susceptibility to cracking depended on the structure of the alloys. Single phase ferritic alloys did not crack regardless of their impurities and nickel content. On the contrary, alloys containing martensite cracked except the cases in which neither phosphorus nor more than 0.5% nickel was contained, and high nickel content resulted high susceptibility to cracking. Since the martensite indicates that γ was present during heating, cracking may be effectively prevented by avoiding γ formation during heat treatment with selection of suitable heat treatment or removal of the austenite forming element such as nickel, carbon, manganese or nitrogen. For this purpose, it may also be effective to avoid the coexistence of phosphorus and more than 0.5% nickel when martensite is contained in structure.
Experiments at controlled potential indicate that anodic dissolution was a prerequisite of cracking.抄録全体を表示PDF形式でダウンロード (593K) -
平井 正典, 佐藤 有, 大平 五郎1974 年 38 巻 5 号 p. 426-433
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーWhen the molten metal is freezing unidirectionally by convectional heat transfer of the air, its heat equation can be expressed as follows:
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where h is the heat transfer coefficient, S is the heat transfer area, T is the temperature of sample, T∞ is the temperature of air at the infinity, M is the weight of sample, Cp is the specific heat at constant pressure, L is the latent heat of sample, t is the time, and fs is the fraction solidified.
The relation between t and T was obtained from the observed cooling curves of samples. After substituting them into the heat equation, the relation between fs and T was then calculated by graphically integrating the current equation.
The results obtained were compared with the relation between fs and T based on the equilibrium solidification or the nonequilibrium solidification proposed by Pfann et al.
It was found that fs was retarded compared to the two cases mentioned above. This was considered due to the solute built-up in the liquid at the solid-liquid interface during solidification as observed by E.P.M.A.抄録全体を表示PDF形式でダウンロード (836K) -
亀田 和夫, 阿座上 竹四, 亀田 満雄1974 年 38 巻 5 号 p. 434-439
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe values of E.M.F. of liquid Au-In and Au-Sb systems have been measured in the temperature ranges from 700 to 950°C and 700 to 800°C, by means of the galvanic cells composed of
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\ oindentand
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\ oindentThe values of E.M.F. obtained for the Au-In system showed a good stability and linear relationships with temperature. While, the values obtained for the Au-Sb system were somewhat unstable and showed less reliability as compared with that of the Au-In system.
The activities of both components for the Au-In system show a considerable negative deviation from Raoult’s law over the whole concentration range. As for the Au-Sb system the activities of antimony show an extremely large negative deviation in the gold-rich region, it exhibits a sharp rise at the composition of about NSb=0.2 and finally leads to a slight positive deviation in the antimony-rich side. The sign of the temperature dependence of the activity of antimony changes to negative at about NSb=0.35. On the contrary, the activities of gold show a rather large negative deviation over the entire range of concentration.
The maximum values of the heat of mixing are −3.30 kcal/mol for the Au-In system at about NIn=0.45 and −4.75 kcal/mol for the Au-Sb system at NSb=0.27.
In addition, other thermodynamic functions were calculated on the basis of the results obtained.抄録全体を表示PDF形式でダウンロード (394K) -
川原 浩司1974 年 38 巻 5 号 p. 440-446
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe mechanism of ridging occurring in ferritic stainless steels was studied, using a high-purity 17%Cr-Fe alloy consisting of a solidification structure of columnar grains. Experiments were carried out with three kinds of plates cut from the ingot directly, on the basis of the relationship in the growth direction of columnar grains to the rolling direction. Results obtained were as follows: (1) In the high-purity stainless steel, which does not contain carbide arrays and δ ferrite bands, ridging phenomenon also appears. (2) Ridging phenomenon is found to depend strongly on the solidification structure, especially the growth direction of columnar grains in a plate. (3) Whether or not a plate has the grains elongated after rolling determines the occurrence of ridging, showing a close connection with the shape of deformed columnar grains in plates. (4) There is no particular correlation between ridging and the rolling texture. (5) In the tensile test of a thin as-cast specimen, a surface relief similar to a ridging was observed, which is probably caused by a rotation of the columnar-grains orientations with slip.
From the results mentioned above, a model is proposed, that is, the ridging may be a phenomenon resulting from a rotation of the elongated-grains orientation under tensile deformation.抄録全体を表示PDF形式でダウンロード (905K) -
池野 進, 佐治 重興, 堀 茂徳1974 年 38 巻 5 号 p. 446-451
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーEffects of 0.5, 1, 1.3, 2 and 4%Ti on the ageing characteristics of Cu-Ti alloys were investigated by microhardness measurement, electron microscopy observation and X-ray diffraction technique. The results are summarized as follows:
(1) The shapes of the age hardening curves in the alloys containing more than 1.3%Ti, showed an abrupt increase at the very early stage of ageing. However, in the alloys containing 0.5 and 1%Ti, the incubation-like period were observed on the age hardening curves at the early stage.
(2) For the Cu-(1.3∼4)%Ti alloys, fine precipitates, called the modulated structure, were observed in the very early stage of ageing. For the alloys containing less than 1%Ti, no precipitates were observed in the early stage of ageing, but coherent spherical particles appeared at random with progressing of ageing and then the number of particles increased.
After the number of particles increased to the maximum, the particles coarsened according to a t1⁄3 law. And they became aligned along ⟨100⟩.抄録全体を表示PDF形式でダウンロード (1040K) -
田井 英男, 堀 茂徳1974 年 38 巻 5 号 p. 451-455
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーEquilibrium phase diagrams for the CdTe-Sn and CdTe-Pb systems have been determined by means of differential thermal analysis, X-ray diffraction and microscopic examination.
The CdTe-Sn and CdTe-Pb systems can be considered as pseudobinary systems from results of X-ray experiment. Phase diagrams of these systems are simple eutectic type. Eutectic point of each system is determined as 232°C, 99.995 mol%Sn for the CdTe-Sn system and 327°C, 99.94 mol%Pb for the CdTe-Pb system. Eutectic compositions were determined by extrapolation of the liquidus equation of the dilute solution:
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\ oindentMutual solid solubilities of the CdTe-Sn and CdTe-Pb systems could not be detected by X-ray analysis.抄録全体を表示PDF形式でダウンロード (503K) -
宮城 政和, 新 成夫1974 年 38 巻 5 号 p. 455-462
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe decomposition processes below 300°C in metastable β-type titanium alloys, Ti-Mo, Ti-Cr, Ti-Fe, Ti-Mn and Ti-V, were investigated by means of X-ray diffraction technique. The results obtained were as follows: (1) Side-bands were observed in the Debye-Scherrer patterns obtained from the alloys which contain more than a certain amount of some solute elements during the isothermal aging at 250 and 300°C. The side-bands were observed in the Ti-Cr, Ti-Fe, Ti-Mn and Ti-V alloys in which the morphology of the ω phase is the cubic type, while the side-bands were not observed in the Ti-Mo alloys in which the morphology is the ellipsoidal type. (2) The side-bands appeared in a Ti-12%Mn alloy become stronger and approach the main diffraction lines with increase in aging time. In this process, the asymmetry in position, intensity and configuration of the side-bands becomes remarkable with the progress of aging. From the analysis of an oscillation crystal photograph obtained from a single crystal of the Ti-12%Mn alloy oriented with [001]β vertical, it was found that the modulated structure is formed on the {100}β planes. (3) The side-bands were also observed in Ti-20%V and Ti-25%V alloys during isothermal aging at 250°C. However, the decomposition process similar to the phase separation as reported by Harmon et al. was observed in the case of aging those alloys at temperatures between 300 and 400°C. It is concluded that in this case the matastable β phase decomposed into two bcc phases of different composition, i.e. β→β+βH reaction prior to the β→β+ω reaction, where βH is the solute rich precipitate.抄録全体を表示PDF形式でダウンロード (965K) -
池田 徹之, 多賀 清二, 西 成基1974 年 38 巻 5 号 p. 462-471
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーThe present investigation examined thickness ranges and conditions to form the super-saturated solid solution and the equilibrium phase in Al-3% Mn alloy, which had a strong tendency to produce the supersaturated solid solution and remarkable section-sensitivity, by means of rapid cooling in various solidification conditions. Then the experimental procedures used were measurements of micro-vickers hardness and lattice parameter, thermal analysis and microscopic observation. The results obtained were as follows:
(1) The structural diagram of Al-3% Mn alloy concerning the average solidification rate was established from the changes of hardness and lattice parameter for the thickness up to 8 mm.
(2) The minimum solidification rate d(Δε)⁄dt required to form each solidified structure was 4.9×10−2 cm/sec, 1.5×10−2 cm/sec, and 1.0×10−2 cm/sec for the completely super-saturated solid solution, the incompletely super-saturated solid solution and the primary compound+eutectic phase, respectively.
(3) Assuming the solidification model of hexagonal array in the solid-liquid region for the supersaturated solid solution, the solid fraction fs(D0,θ) was proportional to the time θ=(t−ti) at a constant thickness D0. At a constant time t0, the solid fraction curve fs(D,t0) showed such curves as being d2fs⁄dD2>0 for the incompletely super-saturated solid solution and d2fs⁄dD2<0 for the completely super-saturated solid solution.抄録全体を表示PDF形式でダウンロード (1311K) -
横山 亨, 武澤 隆1974 年 38 巻 5 号 p. 472-473
発行日: 1974年
公開日: 2008/04/04
ジャーナル フリーPDF形式でダウンロード (168K)
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