材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
33 巻 , 375 号
選択された号の論文の22件中1~22を表示しています
  • 新庄 輝也
    1984 年 33 巻 375 号 p. 1445-1450
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
  • 堀 茂徳, 田井 英男, 豊田 真彦, 川口 清一
    1984 年 33 巻 375 号 p. 1451-1456
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Recovery and recrystallization processes of pure silver and its alloys containing about 0.1 at % of cadmium, tin or antimony deformed 40∼90% by rolling at-196∼60°C were examined by micro-Vickers hardness and electrical resistivity measurements.
    The recrystallization temperature of these alloys decreased with increasing area reduction and with lowering deformation temperature. The solute elements which have large binding energy with atomic vacancies raised the recrystallization temperature of silver, because they trap atomic vacancies and inhibit their migration.
    When the kind and the quantity of the solute elements were fixed, ΔρE/ΔρW was shown to be almostly constant independent of the degree and the temperature of deformation, where ΔρW and ΔρE are the increment of specific resistivity by the plastic deformation and the decrement of it by the recovery process, respectively. For a definite deformation condition, the recrystallization temperature of the alloy increased with increasing ΔρE/ΔρW.
  • 田中 芳雄, 井戸 守, 古下 昌彦
    1984 年 33 巻 375 号 p. 1457-1462
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Crystal bending induced by a cone indentation of the {100} face of copper was comprehensively investigated by comparing asterisms of the Laue spots newly obtained on the vertical plane with those previously taken on the horizontal plane. The bending cusp which was made along the boundary of individually active slip systems became sharper in the region of severer deformation, while it relaxed in the region where cross slips took place.
  • 吉田 松夫, 杉林 俊雄, 池上 皓三
    1984 年 33 巻 375 号 p. 1463-1469
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The deformation and strengeth of single lap joints of glass cloth/vinylester resin laminated plates under tensile-shear load were investigated analytically and experimentally. The strain distributions of the joints were analyzed by the finite element method. In the analysis, several different boundary conditions were applied to the tensile shear loading condition. The analyzed strain distributions for those boundary conditions were compared with the experimental results, and the boundary condition corresponding to the experimental loading state was determined.
    The strength of the joints was evaluated by applying the strength law established for each part under the combined stress state to the analyzed stress distributions in the adhesive layer, adherend and their interfaces. The evaluated results were compared with the experimentally determined joint strength. The results obtained are as follows.
    (1) The deformed state of the single lap joints can be represented by using the finite element strain analysis.
    (2) The strength of the joints increased as the overlap length increased under constant adherend thickness, but the strength did not always increase with the increase of adherend thickness under constant overlap length.
    (3) The evaluated strength of the joints showed good agreement with the experimentally determined strength for the relatively thin adherend.
  • 山口 豪, 王 志剛, 井上 達雄
    1984 年 33 巻 375 号 p. 1470-1476
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The paper deals with the simulation of carburized-quenching process as a coupling problem among temperature, metallic structure and stress with consideration of their dependence on carbon content. The distribution of carbon content was determined by using the diffusion equation. A set of coupled fundamental equations of heat conduction, transformation kinetics and elastic-plastic constitutive modelling were formulated to obtain temperature, metallic structure and stress.
    The carburized-quenching process of a gear of nickel-chromium steel (SNC 815) was analyzed using the finite element technique. Also, the normal-quenching process was analyzed for comparison. The calculated results were compared with the experimental data of the distribution of residual stress, Vicker's hardness and micrographs showing metallic structures as well as carbon content.
  • 内藤 正鄰, 台丸谷 政志, 浜田 恒平
    1984 年 33 巻 375 号 p. 1477-1481
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The present paper is concerned with a problem of longitudinal plastic waves in a bar subjected to tensile impact. The effect of the variation of impact velocity on the propagation plastic waves and the formation of strain plateau in the strain distribution is discussed experimentally and theoretically. Impact tensile tests of copper specimens were carried out by an impact testing apparatus using a falling weight. The plastic strain distribution of the specimen was measured and the time history of plastic waves at various stations along the specimen was observed, together with the variation of impact velocity during impact. Theoretical calculation was performed by using Malvern's strain-rate dependent theory, taking account of the attenuation of impact velocity.
    The results obtained are summarized as follows:
    (1) The experimental results showed that the strain distribution along the specimen decreased with the increase of the distance from the impact end and no strain plateau at neighborhood of the impact end appeared.
    (2) The theoretical results under the condition of decreasing impact velocity predicted also no strain plateau and almost agreed with the experimental results.
    (3) The formation of strain plateau may be limited to the case of a constant impact velocity, though it is related to the strain-rate dependent nature of material, the impact velocity and the duration of impact time.
  • 伊達 秀文
    1984 年 33 巻 375 号 p. 1482-1487
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The present paper is concerned with the measurement of flow stress of poly vinyl chloride at high strain rate using the technique in which a projectile collides with an elastic bar. The dynamic yield stress of polymer was obtained using one dimensional elasto-plastic wave propagation analysis by Hutchings (1979) who employed the same technique. But one of the assumptions used in the Hutching's theory is not consistent with the experimental results in this paper. Therefore, the assumption that elastic wave velocity in the projectile is constant with impact velocity is used in this paper instead.
    The results showed that the modified yield stress increased with impact velocity, though the stress from Hutchings's theory was roughly constant. The modified yield stress agreed with the stress obtained from strain gages qualitatively and coincided also with the experimental data of other papers.
  • 岩舘 忠雄, 田中 泰彦, 兜森 俊樹, 竹俣 裕行
    1984 年 33 巻 375 号 p. 1488-1492
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    In order to study the behavior of crack opening displacement at the maximum load, CODmax, per British Standard 5762, the COD tests were conducted using 3.7% Ni-Cr-Mo-V steel in the upper shelf region. The test results obtained are as follows.
    (1) The CODmax value depends on the specimen size and yield strength of the material.
    (2) The CODmax value increases with increasing specimen size, of which the tendency is remarkable in the material with lower yield strength.
    (3) When the yield strength increases, the CODmax value decreases, especially more remarkable in the larger specimen.
    (4) The following correlation between CODmax and 2mm V-notch Charpy impact energy is confirmed.
    CODmaxY=m'(CVN-usY-0.11)
    (5) The constant m' depends on the specimen thickness B.
    m'=0.010√B
  • 木戸 光夫, 伊藤 尚, 中佐 啓治郎, 武井 英雄
    1984 年 33 巻 375 号 p. 1493-1498
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Crack initiation in delayed failure under repeated loads of various stress wave forms was investigated using the notched specimens of SNCM 439 quenched and tempered at 473K. The results obtained are as follows:
    (1) The crack initiation time ti and the threshold stress σSCC were decreased by superposition of repeated load on the sustained load, the degree of which increased with an increase of stress increasing period at constant frequency, i. e. ti and σSCC decreased most under repeated loads with positive saw tooth wave, followed by those with sinusoidal, negative saw tooth and trapezoidal.
    (2) The reason why the crack initiation time ti and σSCC decreased when the stress wave form had a long stress increasing period seems to be that the corrosive reaction is activated during the stress increasing period, since the protective film on notch root surface is destructed mechanically by repeated stress. In the stress decreasing period, on the other hand, the protective film destructed mechanically by repeated stress is reformed, so that hydrogen might invade less into material when the stress wave form has a long period of stress decreasing or stress holding.
  • 古郷 佐八郎, 荻野 春之助, 中川 隆, 小林 正孝, 浅見 克敏
    1984 年 33 巻 375 号 p. 1499-1505
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Fatigue tests under two different axial loading conditions, which were completely reversed stress (R=-1) and pulsating tension stress (R=0) conditions, were performed on the as-cast and heat-treated materials of spheroidal graphite cast iron. The macro and microscopic observations of the fatigue-fracture surface of the specimens were carried out by SEM and their fatigue strength was investigated. The results obtained are summarized as follows:
    (1) The tensile strength of the heat-treated material varied largely from 455N/mm2 for the annealed specimen to 920N/mm2 for the bainitized specimen. However, the difference due to the amount of added Mn was found to be little.
    (2) The fatigue strength of the as-cast material for R=0 was found to be much lower than, that for R=-1, and their fatigue limits were σw=172N/mm2 for R=-1 and σu=114N/mm2 for R=0, which is about 35% lower than the former.
    (3) The fatigue limits of the annealed, normalized, and bainitized specimens for R=0 were in a comparatively narrow range of σu=110∼123N/mm2. No specific influence by heat treatment or by the amount of added Mn was recognized on the fatigue strength of these specimens.
    (4) Fatigue cracks appeared from such internal defects as small pinholes. Therefore, it is considered that the heat treatment or the amount of added Mn would not affect the fatigue strength of these materials so much.
  • 三浦 健蔵, 熊田 誠, 大井 利継
    1984 年 33 巻 375 号 p. 1506-1512
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The effect of surface condition on fatigue strength, corrosion fatigue prevention and the corrosion fatigue damage which occurred in the specimen were investigated in fresh water and aqueous solution containing sodium nitrite inhibitor at 80°C using relatively large Cr-Mo cast steel specimens.
    A finely machined specimen (surface roughness, R<2s), a roughly machined specimen (R≅20s) and a shot blusted cast skin specimen had a clear fatigue limit in air. The fatigue limit of the roughly machined specimen fell to about 90% of that of the finely machined specimen, but the fatigue limit of the shot blusted cast skin specimen became very high compared with those of the finely and the roughly machined specimens. The fatigue strengths of the finely and the roughly machined specimens in fresh water at 80°C were the same level. Many corrosion pits and microcracks occurred on both the finely and the roughly machined specimens. The shape of microcracks was semielliptical when the stress amplitude was relatively high, but the microcracks were combined with each other and were stretched along the surface of the specimen when the stress amplitude was low. The fatigue strengths of the finely and the roughly machined specimens in aqueous solution containing. sodium nitrite inhibitor at 80°C had the same level of fatigue limit as those in air, and corrosion pits and microcracks were not observed. On the other hand, the behavior of the fatigue strength of the shot blusted cast skin specimen in fresh water and aqueous solution containing sodium nitrite inhibitor at 80°C was different from that of the machined specimens.
  • 本田 和男, 鳥居 太始之, 戸井 詔彦
    1984 年 33 巻 375 号 p. 1513-1519
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The purpose of this paper was to investigate quantitatively the effect of tensile residual stress on fatigue crack propagation based on the experimental facts and the linear fracture mechanics. In the experiment, the X-ray oscillating stress measurement method was applied to examine the residual stress distribution around a precrack in the plate specimens which were made so as to have longitudinal residual stress due to water cooling from the temperature below 873K. By using these specimens, it was confirmed that the acceleration of the fatigue crack propagation from the precrack in tensile residual stress field was induced by the crack opening due to the tensile residual stress. On the other hand, it was found that the initial stress intensity factor of precrack in tensile residual stress field could be calculated by substituting the measured value of tensile residual stress for the crack opening stress on the ideal crack surface in a linear fracture mechanics model. The effective stress intensity factor range calculated from the initial stress intensity factor of precrack was useful for understanding of the fatigue crack propagation from the precrack in tensile residual stress field.
  • 浅見 克敏, 寺沢 正男
    1984 年 33 巻 375 号 p. 1520-1526
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Near threshold fatigue crack growth behavior of high strength steels has been investigated by varying the yield strength (921∼1845MPa) and stress ratio (R=0.06, 0.4). Three kinds of Cr-Mo steels were used in this investigation and the fatigue tests were carried out at room temperature and in laboratory air.
    The threshold stress intensity factor range, ΔKth, generally decreased with increasing yield strength and/or stress ratio. Then, the influence of stress ratio decreased as the yield strength became high. Several of the materials used, however, showed different tendencies.
    These observations were rationalized in terms of the concept of oxide-induced crack closure. Then, it was found that the intergranular fracture occurring at low fatigue crack growth rates remarkably encouraged oxide-induced crack closure in thee case that the area percentage is more than 50%, and it played the important role to the behavior of ΔKth.
  • 村上 理一, 伊藤 恵二, 秋園 幸一
    1984 年 33 巻 375 号 p. 1527-1532
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Machines and structures often encounter repeated impacts in practice. So, it is very important to study fatigue fracture of steel under repeated impacts. Usually a rotating disk type impact fatigue testing machine is used for such study, but the analysis of the data obtained by using this machine is considerably difficult, because the impact phenomenon is transient and has complex characters. So, a new type of machine was made by modifying a rotating disk type impact fatigue testing machine, and fatigue tests under repeated impacts were carried out. Then, the influences of velocity of repeated impacts and stress ratio on the fatigue crack growth rate of stainless steel were investigated by means of fracture mechanics and fractography. The difference in crack growth rate between repeated impacts and more gradually-applied cyclic load was large. This difference was explained by the effective stress intensity factor based on the equivalent stress ratio which includes the repeated impact loading effect.
  • 八木 晃一, 田中 千秋, 久保 清
    1984 年 33 巻 375 号 p. 1533-1539
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The creep fracture mode for SUS 316 stainless steel under constant creep loading was examined. The intergranular fracture due to the growth of wedge-type intergranular cracks was observed in the case of high stress at temperature below 550°C. The intergranular fracture due to the growth of cavity-type intergranular cracks which were associated with intergranular carbide and σ phase precipitation was observed in the case of low stress at temperatures above 650°C. Between these two conditions, the transgranular fracture was observed.
    The combined creep-fatigue loading tests were carried out under three loading conditions at 550°C, 650°C and 750°C, which gave the intergranular fracture caused by wedge-type intergranular cracks, the transgranular fracture and the intergranular fracture caused by cavity-type intergranular cracks under constant creep loading, respectively. Under these conditions the fatigue specimens were fractured by the transgranular growth of surface cracks.
    The data obtained from the combined creep-fatigue loading tests were evaluated using the linear life fraction damage rule. The rupture life under combined creep-fatigue loading at 550°C was affected strongly by creep damage, φc, and fatigue damage, φf, and the relation of φc and φf was φcf<<1. The specimens at 650°C were ruptured by an accumulation of either φc or φf. The rupture life at 750°C was affected by φc and φf, and the relation of φc and φf was φcf≈1.
  • 高津 学, 荒谷 眞一, 日比野 浩, 三嶋 康玄
    1984 年 33 巻 375 号 p. 1540-1544
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The crack propagation in thermal tempered glass specimens having 9 continuous patterns of local residual stress has been studied. The thermal tempered glass specimens were made with the solid contact method and the immersing method using silicone oil.
    The results show that crack velocity, fragment density and spline were dependent on local residual stress pattern and impact point.
  • 松尾 陽太郎, 村田 博隆
    1984 年 33 巻 375 号 p. 1545-1551
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Generalized stepwise structural models of multi-modal Weibull distribution functions have been established for the bending strength of ceramics. The maximum likelihood estimators of the Weibull parameters for each model were obtained by Nelder-Mead method. By using Akaike's information criteria (AIC), a mono-modal model was selected as the most suitable one for two kinds of bending test data on steatite ceramics. However, it was pointed out that some additional data such as diagnostics data and/or additional strength data were needed.
    The direct and the two-step maximum likelihood methods have been applied to Monte Carlo simulation data of the bi-modal Weibull distribution function for small sample size. The standard deviation and the mean squared error of the maximum likelihood estimators by the two-step method were two or three figures smaller than those of the direct method.
  • 熊谷 雅晴, 奥田 直樹
    1984 年 33 巻 375 号 p. 1552-1555
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Equations to calculate the room temperature density of fused SiO2-MnO-Al2O3 fluxes from their chemical composition were derived. Firstly, the equation based on the additive law was examined using Appen's density factors. For calculation, the chemical composition of the fluxes and the actual density measured by an air picnometer were put into the additive equation with fMnO as an unknowa quantity. Thus the density factor for MnO was detremined as 5.99. Secondly, the multiple regression equation was applied. In this case, the actual density and the chemical composition were treated by a computer to obtain the regression coefficients and the constants. Consequently, the deviation range of the calculated dentity from the actual one was found to be ±0.01g/cm3 both for the additive equation and for the multiple regression equation.
  • 熊谷 雅晴, 奥田 直樹
    1984 年 33 巻 375 号 p. 1556-1558
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    Equations to calculate the room temperature density of the fused SiO2-MnO-CaF2 fluxes from their chemical composition were derived. Firstly, the equation based on the additive law was examined using density factors examined in the preceding paper. For calculation, the chemical composition of the fluxes and actual density measured by an air picnometer were put into the additive equation with fCaF2 as an unknown quantity. Thus the density factor for CaF2 was determined as 2.97. Secondly, the multiple regression equation was applied. In this case, the actual density and the chemical composition were treated by a computer to obtain the regression coefficients and the constants. Consequently, the deviation range of the calculated density from the actual one was found to be ±0.05g/cm3 for the additive equation and -0.04∼+0.03g/cm3 for the multiple regression equation.
  • 平沢 良男, 竹越 栄俊, 井村 定久, 清田 文夫
    1984 年 33 巻 375 号 p. 1559-1565
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    The iron base sintered alloy, which contains a dispersed hard phase, is frequently employed in the valve seat for engine because it has superior wear-resistance. Since the valve seat is exposed to an exhaust gas and becomes high temperature, the measurements of its thermal properties are very important for the analysis of the temperature distribution which affects the thermal stress and thermal strain.
    In the present study, several specimens of the sintered alloy having different porosities were prepared. Further, for a few specimens copper alloy was penetrated in the pore. The specific heat and the thermal diffusivity of the specimens were measured in the range from room temperature to about 800°C and the thermal conductivity was determined by calculation from these measured values.
    The results obtained are summarized as follows:
    (1) The specific heat of the sintered alloy increased rapidly with increasing temperature and had a transformation point at about 750°C where the specific heat became maximum. At high temperatures, the specific heat of the copper alloy penetrated specimen was slightly larger than that of the non-penetrated specimen.
    (2) The thermal diffusivity decreased with increasing temperature and had also the transformation point at about 750°C where the thermal diffusivity became minimum. The diffusivity increased with increasing density and was largest in the copper alloy penetrated specimen.
    (3) The thermal conductivity increased with increasing density, but changed little with increasing temperature except the copper alloy penetrated specimen.
  • 船橋 正弘, 池上 皓三
    1984 年 33 巻 375 号 p. 1566-1571
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
    This paper presents a testing method of interlaminar strength in the laminated direction of glass cloth reinforced plastics. To obtain the mechanical properties in the laminated direction, a method using the laminated thin wall tube specimens was proposed. The stress distribution in the specimen under tensile load was analyzed by using the finite element method. The shape of the specimen having a flat tensile stress distribution was numerically searched by varying the dimensions of specimen. The strain distribution calculated by the finite element method was confirmed by tensile tests of the laminated thin wall tube specimens. The interlaminar strength tests were conducted by subjecting the laminated specimens to axial, torsional and combined loads.
    The deformation in the laminated direction showed nearly elastic behavior up to the fracture of specimens except the case of compressive deformation. The interlaminar strength of the specimens under combined stress was approximately expressed by Hoffman's fracture criterion.
  • 中島 浩二
    1984 年 33 巻 375 号 p. 1572-1578
    発行日: 1984/12/15
    公開日: 2009/06/03
    ジャーナル フリー
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