巻号一覧
49 巻, 11 号
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稲数 直次, Lücke Kurt1985 年 49 巻 11 号 p. 921-927
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーThe recrystallization behavior of a drawn aluminium alloy accompanied by precipitation has been investigated by means of measurements of mechanical and electrical properties, determination of X-ray pole figure and ODF, and transmission electron microscopy.
A duplex fiber texture composed of a strong ⟨111⟩ axial component and a weak ⟨100⟩ one is formed by the drawing to 90% reduction in area. In the case of high annealing temperature (>673 K), the precipitation occurs after recrystallization, therefore, the recrystallization texture is accompanied with a ⟨100⟩ axis component. In the case of middle annealing temperature (∼643 K), the recrystallization and the precipitation behaviors compete mutually, and the “in situ” recrystallization occurs because of the pinning of a migrating sub-grain boundary by fine precipitates, and consequently the ⟨111⟩ axis component remains in the matrix. In the case of low annealing temperature (603 K), firstly precipitates will grow and coalesce, thereafter the recrystallization occurs, because the pinning effect by fine precipitates decreases, and consequently the recrystallization texture is composed of the random components. In the case of long time annealing, the secondary recrystallization occurs, and consequently the ⟨112⟩ axis component is developed.抄録全体を表示PDF形式でダウンロード (1830K) -
川崎 宏一, 加藤 弘1985 年 49 巻 11 号 p. 928-935
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーCold-rolled Al-killed steel sheets with and without boron were laboratory annealed continuously. Nucleation sites of cementite within grains were investigated during aging treatments. The following conclusion was obtained.
(1) Single α-MnS and single AlN precipitates were dispersed homogeneously before aging for both kinds of specimens. MnS+AlN complex precipitates were observed only for specimens without boron.
(2) Single MnS and MnS+AlN complex precipitates were main nucleation sites of cementite. The nucleation site ratio of both types of precipitates was high and increased as the size of precipitates increased.
(3) The distribution density of both types of precipitates over 0.05 μm in size were almost the same as that of cementite within grains. The number of pre-existing precipitates with the high nucleation site ratio was enough for the distribution density of nucleation sites. The nucleation site ratio of AlN was low and did not show any size dependence.
(4) The mechanism in which AlN did not reduce the nucleation site ratio of MnS+AlN complex precipitate was considered to be that AlN was a very thin plate and it covered only a small area of MnS/α-Fe interface where nucleation of cementites occurred.
(5) One of the mechanisms of preference of MnS as nucleation sites of cementite within grains was considered to be the wettability of nuclei at the MnS surface. According to the classical nucleation theory, the activation energy of heterogeneous nucleation of critical nuclei reduced to less than 2% compared with that in the homogeneous case.抄録全体を表示PDF形式でダウンロード (2574K) -
大森 慎一郎, 香山 滉一郎, 橋本 雍彦, 山田 勝紀1985 年 49 巻 11 号 p. 935-939
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーThe phase relationships of the Ni-Cr-B system were determined in the region lower in boron content than the Ni2B-CrB tie line by differential thermal analysis, optical-microscopy and X-ray diffraction. In the studied region, no ternary compound appeared, and the liquidus surface was found to be composed of seven regions of primary crystallization. The primary crystals were nickel solid solution, Ni3B, Ni2B, CrB, Cr5B3, Cr2B and chromium solid solition. Eleven monovariant reaction lines of nine binary eutectics and two binary peritectics appeared as intersections of the regions of primary crystallization. Five invariant points of three ternary eutectics and two peritecto-eutectics appeared as intersections of the monovariant reaction lines. A projection of the liquidus surface on the concentration triangle is presented.抄録全体を表示PDF形式でダウンロード (1885K) -
高木 節雄, 藤野 隆也, 徳永 洋一1985 年 49 巻 11 号 p. 939-944
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーThe low temperature embrittling behavior in Fe-(17-33)%Mn-6%Si alloys has been investigated by Charpy impact tests and scanning electron microscopy. The embrittlement is attributed to the formation of ε martensite, and the fracture proceeds as follows: (1) Voids are formed at the intersecting points of ε martensite plates. (2) The voids are combined along an ε martensite plate and lead to a platelike microcrack. (3) The microcracks are connected together resulting in fracture. This process is thought to be a sort of brittle fracture, because the matrix near the fractured surface is hardly subject to plastic deformation.
If α′ martensite, however, is formed during deformation, the formation of voids at the intersection of ε-plates is suppressed, resulting in ductile fracture when α′ martensite is ductile. An Fe-17%Mn-6%Si alloy which has (γ+ε) structure below 415 K, for example, keeps high toughness down to the low temperature of about 150 K because of the strain induced transformation to α′ martensite.抄録全体を表示PDF形式でダウンロード (2469K) -
臼井 誠, 浅野 滋1985 年 49 巻 11 号 p. 945-951
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーX-ray diffraction and internal friction studies were performed for 19Cr-9Ni steel (SUS304), 17Cr-4Ni-6Mn steel (SUS201) and 15Cr-12Mn steel (NTK S-1). In all the three austenitic stainless steels, hydrogen-induced transformation to the hcp εH phase and a relaxation peak caused by hydrogen were found after cathodic hydrogen charging.
The hcp εH phase was unstable and changed to stable martensites during room temperature aging in air. In 19Cr-9Ni steel, it changed continuously to the hcp ε martensite with the formation of the bcc α′ martensite, as has been reported in the literature. In 17Cr-4Ni-6Mn steel, the aging behavior of the hcp εH phase was quite the same as in 19Cr-9Ni steel, but in 15Cr-12Mn steel, the hap εH phase changed to the hcp ε martensite without the formation of the bcc α′ martensite. This difference in aging behaviors seems to be attributed to the austenite stability caused by alloying manganese.
The hydrogen peak of internal friction was confirmed around 300 K in 19Cr-9Ni steel, which was measured at about 700 Hz in transverse vibration. Similar hydrogen peaks were also detected around 310 K in 17Cr-4Ni-6Mn and 15Cr-12Mn steels under the same conditions. The substitution of alloying nickel by alloying manganese had no effect on the peak shape but slightly shifted the peak position. This hydrogen peak seems to be attributed to a Snoek-type relaxation due to dissolved hydrogen in austenitic stainless steels.抄録全体を表示PDF形式でダウンロード (860K) -
渋木 浩明, 水林 博, 奥田 重雄1985 年 49 巻 11 号 p. 951-955
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーStrain-controlled fatigue tests using a flexural resonant vibration were performed on the miniature specimens of the solution treated 316 stainless steel up to 12×10−4 in the total strain amplitude, εt, between 293 K and 573 K. From the investigations of in situ changes in the resonant period, P, and in the drive force, DF, applied to the specimens during the fatigue tests, the following are obtained. (1) Overlapped on general changes in P and DF, small and step-like changes in P and DF were observed for εt above the fatigue limit and were considered to be associated with a proceeding of fatigue damages. (2) The general change of P observed in the middle stage during the fatigue tests showed a tendency of stableness or increase (softening) at T=333 K but a strong decrease (hardening) at T=573 K. From the detailed investigation into the above mentioned phenomena, it was concluded that the fatigue test with εt above the fatigue limit itself induced an age hardening at T=573 K but not at T=333 K. The age hardening became to be revealed above T=473 K and increased in magnitude with increasing εt.抄録全体を表示PDF形式でダウンロード (732K) -
今井 和郎1985 年 49 巻 11 号 p. 956-962
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーA general method for obtaining kinematical equations (KE) for deformation of a cylindrical crystal specimen due to slip on any number of slip systems along any path of deformation is described. KE obtained are independent of whether the deformation test is performed under tension or under compression. Two types (length type and height type) are defined for each of axial lengths, axis directions and cross-sectional areas, the changes in which can be calculated by KE. Examples of KE are shown for several kinds of typical deformation including deformation along piecewise-commutative paths.抄録全体を表示PDF形式でダウンロード (845K) -
栗下 裕明, 白石 順一, 松原 礼志, 吉永 日出男1985 年 49 巻 11 号 p. 963-971
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリー(Ti0.74Mo0.26)C0.96 (δ phase) and Mo-1.5Ti-12C (β phase) solid solutions, and hypo Mo-10TiC and hyper Mo-40TiC eutectic composites were prepared and deformed by compression in a temperature range from 285 to 2270 K and in a strain rate range from 5×10−5 to 7×10−3 s−1. The strengths of Mo-23.5TiC lamellar eutectic composite reported earlier and those of the above hypo and hyper eutectic composites were analysed from the strengths of component δ and β phases.
It is found that the extremely high strength of the lamellar eutectic composite is due primarily to solution hardening of TiC by Mo, and that the δ phase undergoes an appreciable plastic deformation at 1470 K and above even at 0.2% plastic strain of the composite. The yield strength of the three kinds of composites up to 1470 K is quantitatively explained by the ‘rule of mixture’, where internal stresses introduced by plastic deformation are taken into account. The magnitude of internal stresses in the component phases is evaluated on the assumption that both the components are equally strained. Above 1470 K, however, the evaluated yield strength is considerably larger than the measured strength, indicating that the effects of recovery of the internal stress and phase-boundary sliding become significant at such high temperatures.抄録全体を表示PDF形式でダウンロード (1406K) -
浅山 行昭1985 年 49 巻 11 号 p. 972-980
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーTo investigate the effect of molybdenum rich zone on the notch toughness which was the most significant precipitates in age-hardening of 18%Ni maraging steels, the precipitation behavior during aging of these steels was initially studied by electrical resistivity change, and then the notch tensile strength as a measure of notch toughness was examined on specimens aged under appropriate conditions.
It was found that the molybdenum rich zone precipitated only in the presence of cobalt on aging at lower temperatures. But the precipitation of this zone overlapped that of Ni3Mo which was predominantly formed by aging at higher temperatures.
In the 18%Ni maraging steels containing titanium, the precipitation of the molybdenum rich zone and that of Ni3Mo scarcely overlapped each other on isothermal aging even at higher temperatures. But precipitates based on titanium were produced together with the molybdenum rich zone.
When re-aging was conducted at lower temperatures after aging at higher temperatures, only the molybdenum rich zone was found to precipitate without overlapping other precipitates, although a small amount of nickel rich zone was formed at the begining of the re-aging.
It was found from the tensile testing of notch specimens re-aged after aging at higher temperature that the formation of the molybdenum rich zone resulted in the degradation of the notch toughness in the 18%Ni maraging steel. The reason for it is that even the rich zone would be fine precipitates coherent with the matrix which was able to significantly affect the deformation process.
However, one of the reasons why the 18%Ni maraging steels possess good toughness in spite of their much higher strength on the conventional aging would be that the molybdenum rich zone produced by the combination of cobalt and molybdenum does not consume nickel in the matrix, in contrast to precipitates based on other hardening elements consuming nickel in the matrix.抄録全体を表示PDF形式でダウンロード (1984K) -
湯浅 栄二, 師岡 利政, 葉山 房夫1985 年 49 巻 11 号 p. 981-987
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーAluminum composite containing dispersed graphite particles was prepared by the hot extrusion of mixture of aluminum and graphite powder. Wear characteristic of the composite with various contents and various particle sizes of graphite has been investigated. Experiments were carried out by a pin-on-ring type wear machine at various sliding speeds and at various contact pressures under the unlubricated condition.
The results are as follows: (1) The wear rate increases with increasing sliding speed due to formation of prow at a true contact part between aluminum matrix and counterface of steel and due to its breaking-away at or near the graphite particle. The wear rate attains a peak value at an approximately intermediate sliding speed in the range of the measurement and then decreases with formation of adhesion-layer containing particles of aluminum oxide and graphite. The wear rate increases again with increase of sliding speed due to plastic deformation of the aluminum matrix and tearing of the matrix along the graphite particle. (2) The sliding speed which causes the peak value of wear rate shifts to higher values with increasing graphite content, and it is independent of particle size of graphite. (3) The wear rate in the composite containing 10 vol% graphite is maximum and decreases with increasing graphite content. The excellent characteristic of wear resistance of the composite is obtained over 20 vol% of the dispersed graphite. (4) The wear rate of the composite consisting of coarse graphite particles is smaller than that of the composite consisting of fine ones under a constant graphite content. (5) The occurrence of wear loss in the counterface or of the severe adhesion wear, depending on the sliding speed, is observed for the graphite-free material, but it is not observed for the composite material under the same condition. (6) The wear rate changes depending on the angle θ between the sliding surface and the extruding direction. The wear rate is the minimum at θ=0°, and it increases with increasing θ.抄録全体を表示PDF形式でダウンロード (2392K) -
土佐 正弘, 吉原 一紘, 武井 厚, 斉藤 一男, 岩木 正哉, 新居 和嘉1985 年 49 巻 11 号 p. 988-994
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーSUS 304 stainless steel and Fe were implanted with 1×1017 Ti+/cm2 at room temperature. The surface composition of implanted SUS 304 and Fe at high temperatures was observed in vacuum with AES and XPS.
The precipitation of Ti compounds was found on the surfaces of implanted SUS 304 and Fe. Implanted Ti+ into SUS 304 and Fe, which existed near the surfaces of metals, diffused into the inside of the surfaces and reacted on C and N in metals. At about 600 K, TiC precipitated on the surfaces of both SUS 304 and Fe. The precipitated TiC disappeared at about 1100 K and TiN precipitated on the surface of SUS 304, while on the surface of Fe this change was observed at about 750 K.
The surface precipitation behavior is explained as follows: As TiN is thermodynamically more stable than TiC, the latter reacts on N which diffuses from the bulk of metal, and changes into TiN. The diffusion coefficient of N in Fe is larger than that of N in SUS 304. Therefore, the precipitation temperature of TiN on the surface of Fe is lower than on that of SUS 304.
This precipitation behavior can be applied to the surface treatment of various metals.抄録全体を表示PDF形式でダウンロード (924K) -
品田 豊, 西 義1985 年 49 巻 11 号 p. 995-1002
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーThe effect of the salt composition on the Na2SO4-NaCl induced hot corrosion of Ni-10%Cr-(2%, 5%)Al and Ni-20%Cr-(2%, 5%)Al alloys was examined by a modified coating test in still air in a temperature range from 973 to 1373 K.
Corrosion losses of Ni-Cr-Al alloys by Na2SO4 increased abruptly with the addition of NaCl, and showed maximum values at 10-25%NaCl mixtures. The corrosion losses by the salt mixtures also indicated maximum values at a temperature about 1100 K. Therefore, a peak was recognized at a specific range of salt composition and temperature on an iso-corrosion contour map of the alloys. But the condition varied slightly with the contents of chromium and aluminum.
Hot corrosion of Ni-Cr-Al alloys induced by the salt mixtures is not any oxidation accelerated by the action of a small amount of salt but abnormal corrosion caused by the direct reaction with a large amount of salt, in contrast with that of pure nickel or Ni-Cr binary alloys. In the corrosion process chromium and aluminum are fluxing selectively from Ni-Cr-Al alloys to the molten salt mixtures as Na2CrO4(CrO42−) and NaAlO2(AlO22−). Then only nickel and Ni3S2 are formed as solid phase corrosion products. After Na2CrO4 has been consumed for the formation of nickel sulfide, the abnormal process stops and turns to normal oxidation forming solid phase oxide.抄録全体を表示PDF形式でダウンロード (1450K) -
三輪 謙治, 大橋 照男, 福迫 達一1985 年 49 巻 11 号 p. 1002-1008
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーOff-eutectic Al-1.5 mass%Fe alloys have been stirred rotationally at the rates from 0.83 s−1 to 12.5 s−1 in a partially solidified state, and variations of eutectic structures and apparent viscosity have been studied. Furthermore, Al-Al3Fe eutectic alloys have been solidified unidirectionally with stirring, and the effect of stirring on the growth morphology of the solidification front has been studied. Al-Si eutectic alloys have been also studied with the same procedure. Component phases in the Al-Al3Fe eutectic are separated by stirring in a partially solidified state. The apparent viscosity of Al-1.5 mass%Fe alloys decreases temporarily in the beginning of the eutectic reaction at most stirring rates. Eutectic Al3Fe grows as a leading phase at the solidification front without stirring, but eutectic α phase partly grows dendritically and becomes a leading phase by stirring. Then eutectic Al3Fe phases form primarily in a residual liquid. The dendritic and leading α phase covers the solidification front more widely with increase in stirring rate. The effect of stirring on the growth morphology of the solidification front in the Al-Si eutectic alloys is similar to that of the Al-Al3Fe eutectic alloy.抄録全体を表示PDF形式でダウンロード (3153K) -
江南 和幸, 堀 信弘, 吉田 智信, 稔野 宗次1985 年 49 巻 11 号 p. 1009-1015
発行日: 1985年
公開日: 2008/04/04
ジャーナル フリーEffects of V and Nb addition on the β-grain refining and mechanical properties of Cu-Zn-Al shape memory alloys were investigated by optical microscopy, tensile testing, X-ray analysis and fractography. It was found that the V addition is very effective in reducing β-grain size, and the mean grain size less than 100 μm was obtained by only 0.4 mass%V addition. The Nb addition was also effective in reducing β-grain size and, in this case, more than 1% addition was needed to obtain the mean grain size less than 100 μm. The β-grain size is sensitive to thermomechanical treatments of alloys, and the warm-rolling in the α+β two phase region at about 823 K followed by recrystallization at 973 K was found to be the most effective in both the alloy systems. The minimum β-grain size 60 μm for the V-added alloy and 85 μm for the Nb-added alloy were obtained in the present investigation. Influence of the β-grain size on the mechanical properties was investigated by tensile testing. It was found that the 0.2% offset stress above Ms temperatures of each alloy depends on the β-grain size and shows the Hall-Petch relation with the β-grain size for the specimens having the mean grain size less than 200 μm. Storable energy during the pseudoelastic deformation cycle increases with decreasing β-grain size, while the percentage of energy loss corresponding to the hysteresis loop of the stress-strain curve decreases with decreasing grain size. The latter, however, increased with increasing amount of alloying elements. The SEM observation of the tensile fracture revealed that the grain boundary cracking was remarkably suppressed by the V and Nb addition and the fracture mode changed from the brittle fracture to the ductile fracture with decreasing β-grain size.抄録全体を表示PDF形式でダウンロード (2643K) -
橋本 敏, 伊藤 修, 武川 洋, 三浦 精1985 年 49 巻 11 号 p. 1016-1017
発行日: 1985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 (255K)
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