材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
19 巻 , 196 号
選択された号の論文の11件中1~11を表示しています
  • 古川 淳二
    1970 年 19 巻 196 号 p. 1-9
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 中込 昌孝
    1970 年 19 巻 196 号 p. 10-15
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    In this report, the fatigue strengtn and impact strength of roller chain link-plates subjected to various conditions of heat treatment are shown. The experimental results are as follows:
    (1) The most favorable condition for heat treatment of roller chain link-plates for their fatigue strength will be that the link-plates will be first hardened and tempered, and then austempered and tempered, and that the temperature will be 370°C, HRA 72 for both tempering and austempering.
    (2) For resistance to repeated impact energy from 20kg·cm to 50kg·cm, the most favorable condition for heat treatment of link-plates will be that the link-plates will be austempered, and that the temperature for austempering will be 370°C and HRA 72.
    (3) The link-plates of HRA 78 have proved strongest for repeated impact energy from 80kg· cm to 640kg·cm, but have turned out weakest for fatigue strength.
  • 郡 利矩, 三木 紀幸
    1970 年 19 巻 196 号 p. 16-21
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    One of the most important problems in the field of the strength of materials is the yielding condition under non-uniform stress distribution. In order to determine the yielding condition of metals under non-uniform stress distribution, the authors performed the following experiments.
    (1) Torsion tests on cylindrical mild steel, brass and duralumin test specimens.
    (2) Combined torsion and tension tests on cylindrical test specimens.
    (3) Tension tests of plates having a circular hole.
    (4) Compression tests on two cylinders in contact.
    The results obtained as follows:
    (1) The twisted mild steel, brass and duralumin bars yield, when the mean value of the shearing stress acting in some proper region reaches the Mises's yielding condition.
    The proper region is determined from the nature of the materials and stress distribution.
    (2) The test specimens, subject to an arbitrary combination of twist and tension, yield when the mean value of stresses acting in the region as described above satisfies Mises's yielding condition.
    (3) A plate having a circular hole, which is subject to tension, comes to yield when the mean value of the tensile stress of the minimum section of the plate approaches the point of tensile yielding stress.
    (4) The two cylinders which is pressed in contact comes to yield when the mean value of the stress acting in a circle of diameter 7.5√R22/R×b approaches the point where the stress satisfies Mises's yielding condition.
    The circle passes through the points on the surface of contact where there is no compressive stress.
  • 米谷 茂
    1970 年 19 巻 196 号 p. 22-28
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    When the steel specimens are subjected to repeated tension, residual stress is induced in the body during stress repetition. In this report, the results of measurement of those residual stresses are shown.
    The specimens were repeatedly stressed at four stress levels above and below the fatigue limit, and the residual stress of some specimens in the course of stressing was measured by the X-ray method.
    Stressed at a level below the fatigue limit, the residual stress showed but little change during stress repetition. But stressed at a level above the fatigue limit, there were considerable changes in distribution and magnitude of the residual stress, and this was manifest at a stress level near the fatigue limit.
  • 米谷 茂, 小木曽 克彦, 高橋 克明
    1970 年 19 巻 196 号 p. 29-35
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    This is the report of an experiment made of the residual stress induced by rotary bending of steel. As in the 1st report, four stress levels above and below the fatigue limit are applied repeatedly, and the residual stress of some specimens in the course of stressing has been measured by the X-ray method. Also, the specific volume in each part of these specimens has been measured. Then, the change of distribution of residual stress during stress repetition has been investigated.
    Stressed at a stress level below the fatigue limit the residual stress induced showed but little change. But stressed at a level above the fatigue limit, the residual stress showed considerable changes. This may be the result of the change of the specific volume at each part which goes into inner layers in succession from the outer layer, causing the compressive residual stress.
  • 遠藤 吉郎, 駒井 謙治郎, 岡 清次
    1970 年 19 巻 196 号 p. 36-42
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    Observation has been enacted of behaviours of corrosion fatigue of carbon steel under potential controlled conditions in buffer solutions of various pH values, and electrochemical studies have been made on the characteristics of the materials with respect to its passivation and immunity, as well as on the variation in the potential-pH diagram under the repetition of stress cycles. Cathodic protection is found as not efficient enough for the protection of metals against corrosion fatigue in the solutions of pH1, while the perfect efficiency can be expected at E=-1200mV in pH4 and at E=-1000mV in pH6, being more easy in the solutions of higher pH values. On the other hand, anodic protection is fairly efficient in the solution even of lower pH value, though perfect efficiency is not reached in this instance for protection of metals irrespective of the pH value of the solution. The cathodic protection at the electrode potential which is efficient against the static corrosion is not efficient enough when applied to the material under the repetition of stress cycles in corrosive environments, since the domain of corrosion in the direction of the catholic protection in the potential-pH diagram is expanded, due to the increase in metal activity, in the direction of negative electrode potential in the course of repetition of stress cycles. Perfect catholic protection is inhibited when 1N H2SO4 of pH1 is used, since metal dissolution is observable from the very beginning of stress cycles throughout in spite of the low electrode potential. On the other hand, the domain of corrosion remains in the direction of positive electrode potential in spite of the corrosion fatigue, but in the anodic protection, even at the sufficiently positive potential of higher grade than the Flade potential (EF), metal dissolution is inevitable with stress cycles. The EF is immaterial after all so far as corrosion fatigue is concerned.
  • 佐賀 二郎, 三好 良夫
    1970 年 19 巻 196 号 p. 43-48
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    The substructure formed in coarse grained aluminium subjected to tensile deformation was investigated by X-ray diffraction microscopy. The relations of the revealed substructure to the reflection lattice plane, and to the depth from the surface of the grain, were also studied.
    The results are summarized as follows;
    (1) Formation of substructure in a specimen with relatively coarse grains having similar property like a single crystal is connected with the orientation of crystal grains. When the tension axis of the crystal grain is near its [110] zone axis, substructure is formed in parallel with both the slip line and the deformation band. On the other hand, when it is near the [100] zone axis, the substructure formed is parallel only to the deformation band.
    (2) In a specimen with relatively fine polycrystalline grains, block-like substructure is formed independently of the orientation of grains and reflection lattice plane.
    (3) The substructure is various in size in proportion to the depth from the surface.
    (4) The total misorientation within a grain increases with increasing deformation, which does not seem to have anything to do with the reflection lattice plane, the original grain size or the orientation of the grain.
  • 平 修二, 林 紘三郎, 花山 好和, 渡瀬 善次郎
    1970 年 19 巻 196 号 p. 49-55
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    The X-ray elastic constants are found to be affected by many factors due to the selective nature of X-ray diffraction measurements. It is important to measure quantitatively the effect of these factors, not only to improve the accuracy of X-ray stress measurements, but also to elucidate the deformation mechanisms of polycrystalline aggregates.
    In a previous paper, an experimental and analytical investigation of the X-ray elastic constants was presented. The dependence of the constants on the diffracting plane as well as the change in these constants caused by uniaxial plastic deformation were observed experimentally and interpreted on the basis of crystal orientation, anisotropic elastic constants and deformation texture.
    In the present investigation, similar experimental techniques have been employed to determine the influence of carbon content (or cementite phase) and the effect of pre-working on the X-ray elastic constants of plain carbon steels. The results are reported for five compositions of hot-rolled plain carbon steel ranging in carbon content from 0.01 to 0.91%, and a forged 0.13% carbon steel. All the specimens were fully annealed and electropolished to remove the surface layer affected by machining.
    The following conclusions have been reached as the result of this investigation:
    (1) The absolute values of the X-ray elastic constants, S1 and S2/2, decrease with increasing carbon content, while the X-ray elastic modules, E, increases gradually. This phenomenon cannot be explained by the difference between the elastic constants of ferrite and cementite. It can be explained, however, by the constraint of deformation due to grain boundaries, since ferrite grains of the steels used in this investigation are smaller in size in proportion as the carbon content is larger. The smaller the grain size, the more prodominantly the deformation of the grain is influenced by the grain boundary and the deformation behavior approaches the Voigt's condition (uniform strain).
    (2) The absolute values of S1 and S2/2 of annealed hot-rolled steel decrease in the early stages of plastic deformation until they reach a nearly constant value at large strains.
    (3) In the case of the annealed forged steel, on the contrary, the plastic deformation causes the value to increase.
    (4) The absolute values of S1 and S2/2 of annealed forged steel are smaller at first than those of annealed hot-rolled steel of the same carbon content, but they approach the same constant level at high strain, as the plastic deformation causes change in the values. It is concluded that the X-ray elastic constants are affected according to the type of the pre-working employed before the annealing.
    (5) The values of the constants of the steels used depend upon the diffracting plane. In other words the absolute values of S1 and S2/2 measured on {211} by Cr-Kα radiation are considerably smaller than those measured on {310} by Co-Kα.
  • 佐藤 悌介, 高木 直温
    1970 年 19 巻 196 号 p. 56-62
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    Recently high energy rate forging has been developed. In a high speed stamp forging, the indentation velocity reaches the range of several decades or 100m/s. High speed indentation involves numerous interesting problems from the view points of plasticity, metal physics and metallurgy. The high speed indentation of mild steel has been investigated using cylindro-conical punches of several cone angles.
    In this paper is reported the comparison of strain figure in dynamic indentation with that in static indentation. And in this report the characteristics of strain figures are also studied. By comparing the strain figure with the recrystallized stress zone, it can be concluded that the domain which is uniformly etched in the strain figure agrees with the recrystallized field of the stress zone. In static indentation the uniformly etched domain is wide, and the domain which is etched in the form of individual curved lines is narrow and there are but a small number of lines. On the other hand, in dynamic indentation the uniformly etched domain is narrow, but the domain which is etched in individual curved lines is wide, and there are a large number of lines. In both cases of indentation, static and dynamic, the uniformly etched domain in the strain figure agrees with the work hardening region.
    From the above mentioned points, the following conclusions appear to be valid.
    (1) The strain figure is useful in the research of plastic deformation. Especially so when the strain figure is used with hardness test etc.
    (2) In static indentation the workhardening region is wide. On the contrary in dynamic indentation the workhardening region is narrow, but the irregularly deformed region which is etched in individual curved lines in the strain figure is wide.
  • 丹羽 義次, 小林 昭一, 中川 浩二
    1970 年 19 巻 196 号 p. 63-69
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
    The present paper is concerned with the influences of end friction and Poisson's ratio on stress in compressed rectangular and cylindrical specimens. In numerical calculations, the finite element method was employed. The following conclusions have been made on stress in the compressed specimens.
    (1) The more the friction between the end of the specimen and the platten is reduced and the smaller Poisson's ratio becomes, the more uniform stress is developed in the specimen.
    (2) For sufficiently small coefficients of the end friction, some portions of the end of the specimen slide and the shear stress on the end becomes terrace-like, and the axial stress becomes more or less uniform.
    (3) The stress is similar in both the rectangular and the cylindrical specimens. The difference is that the deviations of the axial stresses from the average for various coefficients of friction and Poisson's ratios are larger in the cylindrical specimens than those in the rectangular ones.
    (4) For a fixed Poisson's ratio with the coefficient of the end friction larger than a certain value, no lubrication can be practically expected, in other terms the stress in specimens with such coefficients of end friction are practically the same as the stress in the specimens completely restrained at the ends. This limit value of the coefficient of the friction varies with Poisson's ratio. For Poisson's ratios 1/3, 1/4, 1/5 and 1/6 in cylindrical specimen, for instance, the limit values of the coefficient of end friction become 0.52, 0.38, 0.31 and 0.26, respectively.
    (5) The load required for the unit axial displacement of the ends of specimen is widely influenced by the Poisson's ratio, the coefficient of end friction and slenderness of the specimen. For the specimen with height-diameter ratio 0.5, for example, the loads required for the completely restrained specimen are larger than those of fully lubricated one by 16.5% and 3.3% with Poisson's ratios 1/3 and 1/6, respectively.
  • 吉田 〓
    1970 年 19 巻 196 号 p. 70-73
    発行日: 1970/01/15
    公開日: 2009/06/03
    ジャーナル フリー
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