巻号一覧
42 巻, 7 号
選択された号の論文の17件中1～17を表示しています
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花立 有功, 三谷 裕康1978 年 42 巻 7 号 p. 643-649
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーThe sintering process of Fe-Ni mixed powder compacts with various particle sizes of the nickel powder and also the mutual diffusion process in the Fe-Ni multilayer specimens with various thicknesses of the nickel layer were analysed by means of the differential dilatometric method and EPMA.
The two experimental results were compared and the effect of nickel particle size on the dimensional change of the compacts during sintering was explained by the unequal interdiffusion between iron and nickel.
The results are summarized as follows:
The compacts containing 10 wt%Ni powder of larger than 63 μm expanded in the sintering at 1150°C for 1 h as long as the maximum nickel concentration at the core of the nickel particle was maintained over 50∼55 wt%. In the compact of a given nickel content, the amount of expansion decreased with increasing nickel particle size due to reduction of the interfacial area for the unequal interdiffusion, and the maximum expansion was observed on the compacts comprising 63–74 micron nickel powders, which have a maximum interfacial area between the iron and nickel phases.抄録全体を表示PDF形式でダウンロード (1097K) -
浅山 行昭1978 年 42 巻 7 号 p. 649-658
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーA study of the aging embrittlement has been made on Fe-12Cr-4Ni-12Co-5Mo and Fe-12Cr-8Ni-2Mo-1Al maraging type alloys.
The notch toughness decreased drastically after some aging time when aged at low temperatures up to 500°C or 520°C. The incubation time varied with the composition of the matrix and aging temperatures. At the aging temperatures up to 450°C, the embrittlement was found to occur when the hardness reached a nearly constant level corresponding to the composition of the matrix.
The activation energies determined from the hardness and embrittlement data were 220±20 kJ/mol.
The embrittlement did not occur when the alloys were aged at temperatures higher than 520°C, but when re-aged at temperatures lower than 500°C, after aging at the high temperatures, the embrittlement occurred again with a shorter incubation time than that of single low temperature aging.
The embrittlement, however, did not occur with the re-aging at the low temperatures after the alloys were sufficiently aged at the high temperatures.
From the above, it is thought that the embrittlement of low temperature aging is not caused by the process analogous to temper embrittlement, but caused by precipitation of clusters or rich zones which are coherent with the matrix.抄録全体を表示PDF形式でダウンロード (1109K) -
財満 鎮雄, 大須賀 章郎1978 年 42 巻 7 号 p. 658-664
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーThe orthogonal dry cutting tests by the application of reverse cutting were performed on aluminium O-material (1100-O) to investigate the characteristics of the reversing cut surface comparing with the characteristics of the surface obtained by finishing cut in the same direction as that in roughing cut from the viewpoints of cutting resistance, the hardening layer, roughness of the cut surface, residual strain, residual stress, etc. The results obtained are as follows.
In reverse cutting, the cutting resistance is larger, the degree of work hardening is smaller, and the depth of the hardening layer is smaller than that in ordinary cutting. If the depth of finishing cut is appropriate to the depth of roughing cut in reverse cutting, the roughness of the cut surface is better than that in ordinary cutting. The residual strain of the cut surface in the cutting direction is tensile strain and is large in the surface layer in both cutting methods, the residual strain in reverse cutting is smaller than that in ordinary cutting. The residual stress of the cut surface in the cutting direction is compressive stress corresponding to the existing residual tensile strain and moves in the interior to the tensile stress to some extent in both cutting methods. The residual stress in reverse cutting is smaller than that in ordinaly cutting.抄録全体を表示PDF形式でダウンロード (741K) -
米谷 茂, 財満 鎮雄, 磯部 雅義1978 年 42 巻 7 号 p. 664-669
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーIt is important to measure the value and distribution of residual stress for clarify its actual condition in the vicinity of the cutting surface, because the residual stress produced in the vicinity of a cutting surface is detrimental to precision manufacturing as it causes strain in the material to be cut and promotes corrosion. In this paper, the authors have conducted orthogonal dry cutting of commercial pure aluminium plates and examined the effects of cutting conditions on the distribution of the residual stress in the vicinity of a cutting surface. Residual stress is measured mainly by a mechanical method. However, as for the measurement of stress in the external surface by X-ray diffraction is also conducted in order to obtain a higher degree of accuracy. The results can be summarized as follows:
The residual stress distribution, in most cases shows tensile stress in the external surface and compressive stress in the interior. A similar tendency can be found in the case of cutting iron and steel materials. The effects of cutting conditions on the residual stress distribution are comparatively simple and systematic, the residual stress being proportional to the cutting speed and the rake angle. On the other hand, the effects of depth of cut are rather complex. Stress in the external surface is rather independant of depth of cut, while the maximum tensile stress in the interior is conversely proportional to it.抄録全体を表示PDF形式でダウンロード (520K) -
財満 鎮雄, 米谷 茂, 磯部 雅義1978 年 42 巻 7 号 p. 669-675
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーIn many cases, residual stress in the vicinty of a cutting surface is reported to be compressive residual stress. However, tensile residual stress can be observed in the case of the cutting surface of aluminium, which shows the complex nature of residual stress generation. In this report, in order to obtain clues for explaining the mechanism of residual stress generation, the authors have conducted orthogonal dry cutting of aluminium plates, and measured plastic strain in the vicinity of the cutting surface by the moiré method and residual stress on the same surface by the mechanical method, studying the relationship between the two from the viewpoint of the residual stress generating process. Under the cutting conditions in this experiment, the result shows that moiré strain in the vicinity of the cutting surface is tensile strain in the direction of cutting and compressive strain in the direction of depth perpendicular to it. Relatively clear relationship is observed between this moiré strain and residual stress. In order to study the generating process of residual stress, the authors have examined plastic deformation of the material to be cut in the vicinity of the edge of a cutting tool, after stopping cutting suddenly. A large amount of plastic defomation exists in the region in front of the cutting tool. The magnitude of this plastic deformation is found to considerably affect the residual stress produced subsequent to the secondary deformation after the cutting tool has passed.抄録全体を表示PDF形式でダウンロード (607K) -
末吉 秀一, 末永 勝郎1978 年 42 巻 7 号 p. 676-682
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーThe microstructure of graphite in low carbon low alloy steel annealed at 680°C after pre-treatments such as normalizing, quenching and cold-rolling was examined in detail.
Graphitization was remarkably promoted by the pre-treatment of quenching or cold-rolling compared to that of normalizing, and the number of graphite nodules increased with increase in graphitization rate.
Graphite crystallized on the preferencial interfaces of the inclusions which were identified as non-metallic inclusions composed mainly of Al2O3, SiO2 or silicates.
The nucleation of graphite may mostly depend on the facility of the dissolusion of cementite into ferrite and the number of the sites suitable for nucleation.
The difference in graphite morphorogy depending on the pre-treatment was observed. In the normalized specimen the growth in the c-axis direction specifically occurred along ferrite grain boundaries, whereas the crystal structures of most graphite in the cold-rolled specimen with ease of graphitization were analogous to those of spheroidal graphite in nodular iron.抄録全体を表示PDF形式でダウンロード (1058K) -
藤永 保夫1978 年 42 巻 7 号 p. 682-688
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーThe structure of oxygen-adsorbed copper {100} and {110} surfaces has been studied by low energy electron diffraction (LEED) technique. The surface structure data obtained by the present author and other researchers are summarized in a diagram as a function of surface temperature and oxygen pressure. Attention has been given to unify the notations of the surface structures in order to facilitate comparison of the data. The diagram, called “oxygen pressure-temperature diagram”, is a kind of the phase diagram for the surface, indicating the dependence of surface structure on oxygen pressure and heat treatment.抄録全体を表示PDF形式でダウンロード (506K) -
宮地 博文, 渡辺 敏1978 年 42 巻 7 号 p. 688-697
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーEffect of the fine precipitates produced in the final annealing on the development of recrystallization texture of 17%Cr stainless steel has been investigated as part of a general study of variations in the recrystallization texture due to various minor elements contained in the steel. The hot rolled bands supersaturated with copper or some of titanium were cold rolled and annealed. The recrystallization kinetics and textures were observed as functions of cold reduction and heating rate in the final annealing. The results are as follows:
(1) In both cases, the recrystallization textures mainly composed of the {111}⟨112⟩ and {111}⟨110⟩ orientations are found to develop more markedly with increasing cold reduction.
(2) The heating rate has a slight effect on the recrystallization textures of the sheets at high cold reductions: sharp {111}⟨112⟩ type textures develop in both cases by the mechanism of “in situ” recrystallization.
(3) At lower cold reductions, the recrystallization texture of the copper-bearing steel depends slightly on the heating rate, whereas that of the titanium-bearing steel markedly depends on the heating rate as in with low-carbon aluminum-stabilized or copper-bearing steels.抄録全体を表示PDF形式でダウンロード (869K) -
木村 希夫, 小中 実1978 年 42 巻 7 号 p. 698-702
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーA new oscillation apparatus has been developed for X-ray diffraction technique. The apparatus is composed of two parts. The one is rotating the specimen around the surface normal, and the other is oscillating it as wide as possible around an oscillation axis.
The use of the apparatus allowed the accurate determination of the materials having coarse grained crystals or textured grains: the maximum grain size adaptable for the present method (oscillating angle, ±30°) was estimated, and found to be about seventeen times (∼850 μm in size) as large as the case without the oscillation.抄録全体を表示PDF形式でダウンロード (599K) -
里 達雄, 小島 陽, 高橋 恒夫1978 年 42 巻 7 号 p. 702-708
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーMany age-hardenable aluminum alloys show a maximum in electric resistivity at the early stages of ageing, and the maximum is known to be due to the formation of G.P.zones. Subsequently there appears a region where no change in electric resistivity occurs (flat-region). It is known that neither the size nor the volume fracion of the zones change in this flat-region, and so G.P.zones are considered to be in a metastable state.
The present workers related the resistivity of the flat-region (flat-value) to the volume fraction of G.P.zones, and determined the limit-temperature for G.P.zone formation (Tlimit) through the dependence of the flat-value on ageing temperature. Tlimit obtained were 110 and 160°C for Al-10%Zn and Al-15%Zn respectively, which were independent of quenching temperature and were in good agreement with the value obtained by other workers.
The flat-value was markedly affected by quenching temperature, and this is because the size and number of the G.P.zones in a unit volume change with quenching temperature, although the volume fraction of the zones is the same.抄録全体を表示PDF形式でダウンロード (564K) -
高橋 稔彦, 南雲 道彦, 浅野 厳之1978 年 42 巻 7 号 p. 708-715
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーMicrostructures which control the ductility of eutectoid pearlite steel were experimentally examined. A concept of pearlite block has been proposed as an area in which crystallographic orientation of ferrite is constant. It was revealed that pearlite block acts as a unit of slip and fracture of pearlite steels. Refinement of austenite grains which is effective in improving the ductility of pearlite steels was analyzed to be due to the resulting refinement of pearlite blocks. Increase in ductility was found to be due to the increase in ductile mode area at the fractured surface. Discrepancies of previous studies regarding the roles of cementite lamellar spacing and pearlite colonies could be consistently explained in terms of the pearlite block concept.抄録全体を表示PDF形式でダウンロード (975K) -
高橋 稔彦, 南雲 道彦, 浅野 厳之1978 年 42 巻 7 号 p. 716-723
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーCrytallographic features and formation processes of pearlite blocks were experimentally investigated. The pearlite block was confirmed to be an area in which the orientation of ferrite is constant including many pearlite colonies. Refinement of pearlite blocks was attained by both the refinement of austenite grains and lowering of the transformation temperature. From the measurement of nucleation and growth rates of pearlite nodules, the number of pearlite blocks per austenite grain was quantitatively predicted to be in good agreement with the observation. Together with the crystallographic features of pearlite nodules, the pearlite block was assigned to be the final stage of a pearlite nodule. Pearlite nodules nucleate at and can grow across austenite grain boundaries.
When the transformation temperature is high, pearlite blocks can be larger than austenite grains. Nucleation sites of pearlite nodules was analyzed to be along intersections of three grains or interfaces of two grains when the transformation temperature was lower or higher respectively.抄録全体を表示PDF形式でダウンロード (1181K) -
石川 眞, 小鹿原 猪一1978 年 42 巻 7 号 p. 724-730
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーThe effect of graphite on the extraction of nitrogen has been studied using graphite and molybdenum crucibles. The results obtained are summarized as follows:
(1) Nitrogen in cylindrically pelleted tantalum with and without one atomic ratio of graphite, or nitrogen in the tantalum rod, was extracted at 2200∼2300°C in the graphite or molybdenum crucible. Nitrogen in the sample with graphite in the graphite crucible was completely extracted within 30 min, whereas in all other combinations of samples and crucibles the percentage extraction of nitrogen for 60 min was found to be less than 30% using the Kjeldahl method as the standard.
(2) The X-ray diffraction patterns for the samples after nitrogen extraction revealed the presence of Ta2C, the formation of which may be due to the incomplete extraction. Furthermore, in a series of extraction with graphite in the graphite crucible at various temperatures ranged from 1800 to 2250°C, it was found that at a higher temperature the extraction was completed with the formation of TaC, while at a lower temperature the proportion of Ta2C tended to increase with decrease in percentage of nitrogen extraction.
(3) From the nitrogen collection curves for the cylindrically pelleted samples with and without graphite in the graphite crucible, a linear relationship was obtained by plotting the logarithm of the ratio of the average residual nitrogen concentration to the initial concentration as a function of the collection time. The slope of the curves representing the rate of extraction at 2300°C indicated severalfold acceleration by graphite addition.
(4) Pelleted samples with one mole ratio of boron, silicon, or silicon carbide in place of graphite were also subjected to vacuum hot extraction, and X-ray diffraction was also made on those products.
It is concluded that the identification of TaC through X-ray diffraction is useful for examination of completeness of nitrogen extraction.抄録全体を表示PDF形式でダウンロード (629K) -
古賀 秀人, 内山 休男, 安芸 隆房1978 年 42 巻 7 号 p. 730-735
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーMany investigators have studied on the reaction between solid iron and liquid zinc. It was reported that above 530°C the iron weight loss increased with immersion time following a parabolic law. But, when pure iron specimens were dipped into pure zinc baths, the iron weight loss did not obey the parabolic law. Also, the iron weight loss of the specimens dipped into pure zinc baths was greater than that of the specimens dipped into iron-saturated zinc baths.
So, to study the effect of the iron concentration in the zinc bath on the reaction between solid iron and liquid zinc, pure iron specimens were dipped into various iron-bearing zinc baths (0.00∼1.40 wt%Fe) at 600°C for 5∼100 min; the growth of alloy layer on the iron surface and the quantity of iron reacted with zinc were measured.
The rate constant A and the time exponent of an equation Fe=Atn changed with the iron concentration in the zinc bath. From metallographic examination, this change was caused by the “drop off” of the alloy layer. Models were proposed to explain the relatron between the “drop off” and the quantity of iron reacted with zinc; the experimental results can be explained in terms of these models.抄録全体を表示PDF形式でダウンロード (516K) -
1978 年 42 巻 7 号 p. 730b
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリー -
奥野 攻, 三浦 維四1978 年 42 巻 7 号 p. 736-742
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーFailure processes of brittle fiber reinforced composite alloys were analyzed by means of Monte Carlo computer simulation. A tensile failure model consisted of 40×40 elements, in which the fiber strength followed Weibull random numbers. The average fiber strength were assumed to be the same at the gage length of composite specimens. The type of composite failure simulated depended upon the fiber strength coefficient of variation (CV). The small CV composite failed at low strength by instanteneous fiber fracture propagation. The large CV composite failure occurred progressively with the fiber pull-out, and its strength was relatively high. The results appeared to provide a good prediction and explanation of the composite strength and the fractographs.抄録全体を表示PDF形式でダウンロード (587K) -
柴田 俊夫, 竹山 太郎1978 年 42 巻 7 号 p. 743-750
発行日: 1978年
公開日: 2008/04/04
ジャーナル フリーPit generation of Inconel 600 in 3.5%NaCl solution at 35°C has been analyzed by a stochastic theory which has been developed for explaining a statistical variation in strength or delayed time for the fracture of solid materials. A large number of measured values of pitting potential by a potential sweep method and induction time for pit generation at a constant potential were obtained with the aid of a multichannel pitting corrosion testing apparatus. The pit generation process of Inconel 600 is found to consist of a parallel combination of two independent processes, each pit generation rate (λ1 and λ2) being simply defined by the potential (E) as follows: λ1=20.4(E−0.378), λ2=1.11×10−13exp(64.2E). The first process having a linear dependence of the pit generation rate on the potential is concluded to control pit generation during the potential sweep. For this case the most probable value of pitting potential (\Bar{E}) increases with the square root of the potential sweep velocity (v), i.e., \Bar{E}=0.221v1⁄2+0.378. The linear potential dependence of λ1 suggests that not an electrochemical but a mechanical break-down of passive film due to the electrorestriction force is responsible for pit generation.抄録全体を表示PDF形式でダウンロード (633K)
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