材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
34 巻 , 380 号
選択された号の論文の21件中1~21を表示しています
  • 長嶋 晋一, 白鳥 正樹, 松川 公映
    1985 年 34 巻 380 号 p. 486-492
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Ferritic stainless steel sheets, containing 17% chromium, tend to form ridges when they are elongated along the rolling direction. This kind of small ridges are formed parallel to the rolling direction, and are called ridging or roping. Since ridging occurs even in deep drawing and injures the external appearance of the products, it is regarded as one of the most troublesome flaws of the stainless steel sheets.
    The purpose of the present study was to calculate the behavior of plastic deformation by the finite element method and to find the most probable model of the combination of orientations of elongated region of grains and the matrix. The experimental results are as follows:
    (1) The hills at the top surface and the valleys at the bottom surface of ridging corresponded each other, just the same as the result reported by Takechi et al.
    (2) The mojor texture components showed no change after about 20% elongation compared with the original one, although after 20% elongation marked ridging was observed.
    (3) The simulation of plastic deformation was carried out by the use of finite element method on the model which contained elongated grains of (001) [110] orientation surrounded by the matrix of (554) [225] orientation. The calculation showed marked ridging when the specimen of the above described model was stretched along the rolling direction, but a little in the 45° to the rolling direction, and less along the transverse direction.
  • 本田 和男, 皿井 孝明, 大森 基司
    1985 年 34 巻 380 号 p. 493-498
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    The purpose of the present study was to clarify the influences of restriction of grains and shape of grains on the deformation behavior of individual grains in polycrystalline metals having texture. The stress and strain in each grain in a rolled steel sheet during uniaxial elastic deformation were analyzed by the finite element method using a plane model of polycrystals, and the influence of texture on the elastic constants of the bulk specimen and that on the lattice strains in grains reflecting X-rays were discussed. The results are summarized as follows:
    (1) The stress in a grain is affected by the condition of restriction of grains and the shape of grains. In the case of the model with a circular grain, the change in stress with crystal orientation becomes large when the deformation of each grain is strongly restricted.
    (2) In the case of the model with an elliptic grain, the mode of deformation is close to the condition of uniform local strain and the influence of restriction of grains is small when the shape of grains is prolate in the direction of applied stress. On the other hand, the mode is close to the condition of uniform local stress and the influence of restriction is large when it is oblate.
    (3) The elastic constants of the bulk specimen are affected by the texture, and their values are dependent on the condition of restriction of grains and the shape of grains.
    (4) The linear relation in sin2ψ diagram does not hold for the metals having texture. From the results for the (310) reflection of the rolled steel sheet, it is said that the influences of restriction and shape of grains on sin2ψ diagram are relatively small and the results calculated from the present models are close to those of a uniform local stress model.
  • 倉元 眞實, 佐々木 敏彦, 梅津 二郎, 西本 圭吾, 吉岡 靖夫
    1985 年 34 巻 380 号 p. 499-505
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    This investigation was made in order to find out a distribution of residual stress on the surfaces ground under various grinding conditions obtained by changing an actual depth of cut, number of grinding and a grinding process under a constant state of a chip cross sectional area. The surfaces of the specimens were ground by only up cut, only down cut and both up and down cut, respectively. The experimental data were analyzed by using both the Dölle-Hauk method and the integral method which takes into account of the stress gradient.
    As a result, the residual stress on the surface of one pass grinding showed higher tensile stress when a larger actual depth of cut took place. And the residual stress of down cut grinding was higher than that of up cut. By repeating another re-grinding on the same surface, the residual stress translated into a compressive stress and then converged into a certain level. On the contrary, the stress gradient changed to positive side in such case.
  • 佐々木 敏彦, 吉岡 靖夫, 倉元 眞實
    1985 年 34 巻 380 号 p. 506-512
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    A new principle of X-ray stress evaluation for a sample with steep stress gradient has been prosed. The feature of this method is that the stress is determined by using so-called φ-method based on the change of φ-angle and thus has no effect on the penetration depth of X-rays. The procedure is as follows; firstly, an average stress within the penetration depth of X-rays is determined by changing only φ angle under a fixed ψ angle, and then a distribution of the average stress vs. the penetration depth of X-rays is detected by repeating the similar procedure at different ψ angles.
    The following conclusions were found out as the result of residual stress measurements on a carbon steel of type S55C polished by emery paper. This method is practical enough to use for a plane stress problem. And the assumption of a linear stress gradient adopted in the authors' previous investgations is valid. In case of a triaxial stress analysis, this method is effective for the solution of three shearing stresses. However, three normal stresses can not be solved perfectly except particular ψ angles.
  • 谷 昇, 石田 毅, 蒲地 一嘉
    1985 年 34 巻 380 号 p. 513-518
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to establish the method of X-ray stress measurement at high temperatures for titanium (Ti), the stress on the Ti surface of Ti clad stainless steels having various thickness ratio of Ti to stainless steel was measured at R.T.-500°C by using CoKα radiation and {11·4} plane.
    The results obtained are as follows:
    (1) The temperature dependences of Bragg's angle for Ti in the state of no strain “2θ0” and X-ray stress coefficient “K value” were expressed well by using experimental functions.
    (2) The measured stress was considered reasonable because of close agreement between the measured and the calculated values.
    (3) The thermal stress was determined only by the thickness ratio of Ti to stainless steel.
    (4) The reason for the loop of thermal stress is that the yielding of Ti occurs at high temperature during the heating process but appears at low temperature during the cooling process.
  • 後藤 徹, 小西 隆
    1985 年 34 巻 380 号 p. 519-524
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    The effect of specimen curvature on X-ray stress measurement was investigated for the case of the side inclination method. The measured value of stress along the curved surface deviated from the true value with an increase in curvature and/or with an increase in irradiated size in the direction along the curvature.
    An analytical method to calculate the apparent stress at a given true stress was developed. And the calibration curves for the curved surface measurement were presented.
  • 小田 明, 宮川 英明
    1985 年 34 巻 380 号 p. 525-531
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Explosion hardened high manganese austenitic cast steel is being tried for rail crossing recently. From the previous studies, it became clear that high tensile residual stress was generated in the hardened surface layer by explosion and microcracks were observed. In this study, therefore, the behavior of surface residual stress in explosion hardened steel due to repeated impact loads was examined and compared with those of the original and shot peened steels.
    The results obtained are summarized as follows:
    (1) In the initial stage of the repetition of impact, high tensile surface residual stress in explosion hardened steel decreased rapidly with the repetition of impact, while those of the original and shot peened steels increased rapidly. This difference was attributed to the difference in depth of the work hardened layer in three testing materials.
    (2) Beyond 20 impacts the residual stress of three test specimens decreased gradually, and at more than 2000 impacts the compressive stress of about 500MPa was produced regardless of the histories of working of testing materials.
    (3) The linear law in the second stage of residual stress fading was applicable to this case, and the range of the linear relationship was related to the depth of the work hardened layer of testing material.
    (4) From the changes in half-value breadth and peak intensity of diffraction X-ray, it was supposed that a peculiar microscopic strain exists in explosion hardened steel.
  • 福田 和悟, 竹内 望
    1985 年 34 巻 380 号 p. 533-535
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Thermoluminescence (TL) of calcium borate samples has been investigated. The samples were made by sintering CaB4O7 glass compacts. The X-ray diffraction showed that the samples thus made always contained CaB2O4 crystals besides CaB4O7; the samples consisting of only CaB4O7 could not be made by sintering. The samples showed TL glow peaks at about 75, 115, 150 and 180°C. The 180°C TL peak which can be used for TL dosimetry was found to be characteristic of CaB4O7 crystals.
  • 芳我 攻
    1985 年 34 巻 380 号 p. 536-541
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Mechanical properties of quasi-isotropic glass-cloth laminated composites under uni-axial tension and uni-axial bending loadings were discussed experimentally and theoretically. The results obtained are summarized as follows.
    (1) In regard to the elastic properties, the results calculated by the lamination theory agreed well with the experimental results.
    (2) The degree of anisotoropy of flexural modulus decreased with decreasing the thickness of homologous lamina and the laminated plate became approximately isotropic. “Homologous lamina”means the lamina group which has the same orientation angle of fiber.
    (3) It is clear that both the tensile and flexural strength are anisotropic and their anisotropy can be relaxed by dividing each homologous lamina into many thin laminate and laying-up them alternately.
    (4) A way of theoretical prediction of anisotropic strength was proposed based on the fracture mechanism. In regard to the tensile strength, the estimated values agreed well with the experimental results. As to the flexural strength, however, the estimation did not agree well with the experimental ones except the plate composed of four layers.
  • 鳥居 太始之, 本田 和男, 中野 博美
    1985 年 34 巻 380 号 p. 542-548
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Laminated inhomogeneity and residual stress are known to be important factors controlling fatigue strength of surface-hardened materials. This paper describes an analytical method by which the effects of laminated inhomogeneity and residual stress on cyclic bending deformation behavior can be discussed quantitatively. The analytical results were compared with the experimental results of the clad plates composed of low and medium carbon steels, which were used as a laminated inhomogeneous model. Also, the change of residual stress distribution due to bending fatigue was discussed quantitatively. The results obtained are as follows;
    (1) For the hysteresis loop and surface residual stress change in cyclic bending deformation, the analytical results agreed well with the measured results in S10C base and in clad plates. Also, this analysis enabled us to calculate the cyclic stress-strain relation throughout the thickness of plate subjected to bending fatigue. It was found that the initial residual stress had far stronger influence on the mean stress than the plastic strain amplitude in the calculated cyclic stress-strain relations.
    (2) It was found that this analysis could be applied for evaluation of residual stress distribution throughout the thickness of carburized plates subjected to bending fatigue.
  • 戸伏 壽昭
    1985 年 34 巻 380 号 p. 549-553
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Creep and its recovery behavior of celluloid softened by heating were investigated by uniaxial tension creep tests with stepwise loading and unloading for the case of large strain. Formulation of these deformations was attempted by using a viscous-viscoelastic model.
    The main results obtained are summarized as follows.
    (1) For time-independent strain, the strain under loading was larger than that during removal of stress in the range of high stress. Both of these strains were representable by the viscous-viscoelastic model with 3rd order of stress.
    (2) Creep strain was expressed by a power function of time and the value of exponent in the function was almost constant. The time coefficient of the power function was approximately represented by the viscous-viscoelastic model with 3rd order of stress. But, in the case of huge creep strain, it became necessary to take into account of the terms of more higher order of stress.
    (3) Recoverable strain saturated to a certain value for large creep strain. Further discussion is necessary in order to represent this phenomenon of saturation of recoverable strain by viscous-viscoelastic model.
  • 田中 道七, 福地 雄介
    1985 年 34 巻 380 号 p. 554-560
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    A fine-grating technique using laser diffraction was applied to measure the opening distance of fatigue cracks in the two-layered composite plates which were composed of low carbon steel and ferritic or austenitic stainless steel. A common technique of unloading elastic compliance method was also used for the purpose of comparison.
    It was observed that the crack opening stress near the crack tip determined by the direct observation of the movement of lattice points around the crack tip approximately agreed with that obtained by the unloading elastic compliance method. But the crack opening behavior in the composite plates was quite different from that in the monolithic plates due to the influence of residual stress. An actual stress intensity factor K'max was therefore calculated for the composite plates based on the initial distribution of residual stress, and the crack opening behavior was estimated by using K'max and the crack opening behavior of monolithic plates. The estimated trend showed a good agreement with the observed one for the composite plates composed of low carbon steel and austenitic stainless steel. But, some discrepancy was observed for the composite plates composed of low carbon steel and ferritic stainless steel. This seems to come from a relatively large difference in yield strength between two materials, which may have a large influence especially in the neighborhood of the interface.
  • 城野 政弘, 宋 智浩, 江口 直紀
    1985 年 34 巻 380 号 p. 561-567
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Load-controlled fatigue crack growth tests were carried out on several kinds of ductile materials over a wide region from the linear elastic to the post-yield region, and crack closure behavior was monitored through the tests. The effect of plasticity on crack growth behavior and the limit of validity of the linear fracture mechanics parameters were discussed along with ASTM E647 specimen size requirements. The bulk cyclic plastic strain, even if so small, had the effect to lower the crack opening point. ASTM size requirements were found rational for CT-specimens, while for center cracked specimens were not always sufficient to provide a stable relationship between crack growth rate, da/dn, and stress intensity range, ΔK.
    In addition, peculiar growth behavior of post-yield crack under variable loadings was also briefly noted in the present study.
  • 増尾 義信, 江原 隆一郎, 石橋 保博, 塩田 俊雄, 小松 眞一郎
    1985 年 34 巻 380 号 p. 568-573
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Tensile, fracture toughness, Charpy impact and rotating-bending fatigue tests were conducted on spheroidal, vermicular and flake graphite of pearlitic cast irons prepared experimentally to the purpose of investigating the relationship between the fracture behavior and the fracture surface appearances. The detailed fracture surface observations was conducted by a scanning electron microscope.
    A lamellar pattern was characteristically observed on the fatigue fracture surfaces of the spheroidal and vermicular graphite cast irons. However, striations were not clearly recognized. The lamellar pattern was also found on the fracture surface of the matrix of the flake graphite cast iron. The quasicleavage fracture was observed on the tensile and impact fracture surfaces of the spheroidal and vermicular graphite cast irons. However, no lamellar pattern was observed on the tensile or impact fracture surfaces. It was confirmed that the lameller pattern was corresponded to the lameller pearlite. Micro-dimples were also found in the restricted area of matrix fracture surface of the flake graphite cast iron. This fact provides a clue for identifying the fatigue failure in a practical equipment.
    A stretched-zone-like pattern consisting of quasi-cleavage fracture was observed on the fracture surface of the fracture toughness specimen of spheroidal and vermicular graphite cast irons except the flake graphite cast iron.
  • 市川 昌弘, 座古 勝
    1985 年 34 巻 380 号 p. 574-578
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    A reliability-based design method has been proposed for fatigue under service loads. The method is a practical one because it does not require to conduct fatigue tests on a large number of specimens under the relevant loading condition. In order to develop such a practical method, literature survey was carried out concerning the statistical nature of the cumulative cycle ratio D≅∑ni/Ñi where Ñi was the fatigue life under constant amplitude loading as given by the S-N curve. The survey revealed the following common tendencies: (i) D follows a log-normal distribution approximately, and (ii) ηD, the coefficient of variation of D, is roughly equal to ηN, the coefficient of variation of the fatigue life N under constant amplitude loading. Based on (i) and (ii) above, a reliability based design method was proposed. In this method, S-Ñ/k curve is used as the design fatigue curve, and ∑ni/(Ñi/k)≤1 is used as a design criterion. The factor k is determined from ln 1/k=ln(μD/√1+ηN2)+[Φ-1(Pa)+n-1/2Φ-1(γ)]√ln(1+ηN2) where, μD is the estimate of the mean value of D≅∑ni/Ñi, n is the number of specimens tested to obtain μD, 1-Pa is the reliability goal, 1-γ is the confidence coefficient, and Φ-1 is the inverse function of the standard normal distribution function. The above equation was derived from the condition that the reliability of 1-Pa is attained with the confidence of 1-γ. The most remarkable point in employing this design method is that fatigue tests to be conducted under the relevant loading condition is simply for obtaining μD, hence a large number of samples are not required. A simple design diagram for obtaining k easily was also proposed.
  • 西野 精一, 坂根 政男, 大南 正瑛
    1985 年 34 巻 380 号 p. 579-585
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    This paper describes an X-ray fractography for low-cycle fatigue of SUS 304 stainless steel at 873K in air under two test conditions. The first was the total strain range controlled test using triangular waves at a frequency of 0.1Hz and the second was the stress range controlled test using triangular and trapezoid waves at frequencies from 10-4Hz to 1Hz.
    (1) The half-value breadth obtained from X-ray diffraction on the fracture surfaces of low-cycle fatigue at high temperature was well correlated with the strain range but not with frequency. The half-value breadth was also correlated well with the failure life of the material fractured transgranularly, but was not in the case of intergranular fracture.
    (2) The particle size and microstrain obtained by Fourier analysis for X-ray profiles could be the good parameters for predicting low cycle fatigue life in both of the transgranular and intergranular fracture regimes.
  • 久富 康義, 竹内 望
    1985 年 34 巻 380 号 p. 586-590
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Thermoluminescence (TL) of two types of Li2B4O7 polycrystals prepared by crystallizing bulk glass and sintering powder compact has been investigated. The effect of impurity on the TL was examined by using the samples containing different purities with or without CuCl2 doping.
    In general, these materials showed four glow peaks located at about 95, 160, 205, and 260°C, of which the peak at 260°C was newly found in this study. It was found that the relative intensity of the glow peak depended on the way of preparation of the polycrystalline samples as well as impurities. In the case of doping with CuCl2, the 260°C peak was remarkable in polycrystalline materials made by sintering powder compact, while the 160°C peak was remarkable for those made by crystallizing bulk glass. The characteristics of the 260°C peak which may be suitable for radiation dosimetry were investigated in detail.
  • 加賀谷 忠治, 加藤 政則, 江上 登, 池永 勝
    1985 年 34 巻 380 号 p. 591-594
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Chemical vapor deposition (CVD) method is used to deposit hard wear resistant materials such as titanium carbide and nitride onto a substrate. A suitable masking agent for CVD has not yet been developed at present, however.
    The purpose of this paper was to investigate the possible utilization of inorganic agents for such mask-coating. Both of the portion pre-coated with an inorganic agent and the un-precoated portion have been examined by means of X-ray diffraction analysis, hardness tests and structure observations. The characteristics of the inorganic mask-coating agent were also investigated by differential thermal analysis and gas chromatography.
    The experimental results showed that masking was successful with this agent. This coating was thermally as well as chemically stable and can be used as a masking agent for the CVD treatment.
  • 小田 明
    1985 年 34 巻 380 号 p. 595-601
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Explosion hardened high manganese austenitic cast steel is being tried for rail crossing recently. In this study, in order to clarify the wear characteristics of explosion hardened high manganese cast steel, the wear tests by an Amusler type testing machine were performed under the unlubricated conditions of rolling and sliding-rolling contacts. Furthermore, the behavior of deformation of small testing blocks due to repeated impacts by the dropping hammer method was examined and compared with that of the original steel.
    The results obtained are summarized as follows:
    (1) Under the rolling contact the wear resistance of explosion hardened steel was far superior to the original steel, but under the sliding-rolling contact it made little difference. In the explosion hardened steel containing the defects caused by explosion working or casting, the wear was greatly accelerated.
    (2) The feature of wearing surface of carbon steel tyre was a flaky spalling produced parallel to plastic flow, and that of high manganese cast steel was a fine uneven pitting irrespective of whether it was hardened by explosion working or not. It was supposed that the difference mentioned above is caused by the materials of wearing surface layers.
    (3) The wear fragment of sliding-rolling contact consisted of the flake of carbon steel having the microcracks caused by slip and many fine fragments of manganese steel transferred to the former.
    (4) The amount of compressive deformation of explosion hardened steel due to repeated impacts was smaller than that of the original steel. It seems that the wear resistance of explosion hardened rail crossing is attributable to this characteristic as well as the wear resistance of explosion hardened layer.
  • 喜田 義宏
    1985 年 34 巻 380 号 p. 602-607
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
    Fine ceramic materials have become increasingly important in modern industrial fields due to their unique properties. But few reports describe their machining characteristics.
    This investigation was carried out systematically in wide machining conditions with diamond wheels in order to obtain the machining characteristics of fine ceramics.
    As the result it was found that the ratio of the normal grinding force to the tangential grinding force (Fn/Ft) was very large comparing with the ratio in metal grinding. The ratio was 12-16 for Si3N4-ceramics and 5-6 for SiC ceramics. This shows that SiC ceramics is easier to cause micro-fracture than Si3N4 ceramics. The specific energy, needed to remove a unit volume, changed depending on grinding conditions. The relation between specific energy and non-dimensional undeformed chip thickness was linear on the logarithmic scale. In the condition where the undeformed chip thickness decreased, the specific energy increased. The rate of increase differed depending on ceramic material, and the gradient for Si3N4 ceramics was larger than that for SiC ceramics. The specific energy of Si3N4 ceramics was larger than that of SiC ceramics in the region of small undeformed chip thickness, but the result was the opposite in the condition of large undeformed chip thickness. This shows the difference of machinable characteristics between them.
  • 進藤 明夫
    1985 年 34 巻 380 号 p. 608-614
    発行日: 1985/05/15
    公開日: 2009/06/03
    ジャーナル フリー
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