巻号一覧
39 巻, 11 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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山脇 道夫, 水戸 誠, 菅野 昌義1975 年 39 巻 11 号 p. 1105-1109
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe oxidation behavior of the heat-resistant Fe-base alloy Incoloy 800 was investigated at around 1000°C under oxygen pressures ranging from 1×10−4 to 2×10−1 atm. The rate of oxidation was determined by the weight gain using a Cahn RG Electrobalance. Metallographic, electron microprobe and X-ray diffraction studies of the oxidized specimens were carried out. The rate of oxidation is parabolic, but tends to slightly decrease with the progress of oxidation. Cold rolling of the specimen increased the rate of oxidation. The dependence of the oxidation rate upon oxygen pressure was slightly smaller than that expected when the scale is composed of pure Cr2O3. The oxidized specimen has a layer structure of the outer porous scale, the inner dense scale, the complicated scale-substrate interface region and the internally-oxidized substrate in sequence from the outer side. The outer scale principally contains Cr and Mn, but it also contains smaller quantities of Ti, Fe, Ni, etc. Oxygen partial pressure of the reaction affected the composition of the outer scale. The inner scale is principally composed of Cr2O3. Most of the oxides of Al and Si are present in the scale-substrate interface region and the internally-oxidized substrate region. The existence ratio of the spinel phase against the rhombohedral phase in the outer part of scale increases considerably with the progress of oxidation.抄録全体を表示PDF形式でダウンロード (449K) -
斎藤 安俊, 桐生 堅, 木村 孝, 天野 忠昭, 矢島 聖使1975 年 39 巻 11 号 p. 1110-1117
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe spallinlg behavior of the surface oxide formed on Ni-20Cr alloys with additions of 0.5%Ce or less and 1%Si was studied by means of the microscopic observation of oxidized surfaces and the weight-loss measurement during cooling after the isothermal oxidation in air over the temperature range of 1000 to 1260°C. The spalling initially occurred at the alloy grain boundaries and extended to the interior of the grains. The extent and mode of the oxide spalling depended on the microstructure and morphology of oxidized layers formed on the alloys, which varied with the composition of alloys as well as the time and temperature of oxidation.
In most alloys, the surface oxide began to spall off at about 700°C upon cooling, which was caused by the thermal stress arising from the thermal contraction difference between the alloy and the oxide. Furthermore, the surface oxide severely spalled off again at about 250°C in the Si-containing alloys which formed a continuous layer of cristobalite beneath the surface oxide. It was probably due to the stress resulting from the displacive transformation of high (β) cristobalite to low (α) cristobalite which involved a substantial volume change. The best improvement of oxide adherence in the alloy with additions of both 0.5%Ce and 1%Si could be explained by keying the protective surface oxide to the alloy substrate owing to the formation of the intergranular oxide pegs and the convoluted alloy/oxide interface.抄録全体を表示PDF形式でダウンロード (1105K) -
岩瀬 正則, 藤村 侯夫, 盛 利貞1975 年 39 巻 11 号 p. 1118-1127
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe emf measurements of solid oxide galvanic cells have been carried out to determine the free energy of formation of NiO and PbO and the thermodynamic quantities of liquid Pb-Ag alloys.
The cells are [Cell(I0)] Pt, Ni, NiO/ZrO2(CaO)/Pb, PbO, Ir-Pt(650∼1050°C) [Cell(I)] Pt, Ni, NiO/ZrO2(CaO)/Pb-Ag, PbO, Ir-Pt(650∼1050°C) [Cell(II)] Pt, air/ZrO2(CaO)/Ni, NiO, Pt(700∼1450°C) The obtained results are as follows:
(1) From the emf of cell(II), the standard free energy of formation of NiO was determined as
ΔG0NiO=−55130+19.81T(°K)±100(cal/mol)(700∼1450°C)
(2) Combination of cell (I0) and cell(II) gave the following values for the standard free energy of formation of PbO(1, s),
ΔG0PbO(s)=−51400+23.25T(°K)±120(cal/mol)(650∼879°C)
ΔG0PbO(l)=−44150+16.95T(°K)±120(cal/mol)(879∼1050°C)
(3) By combining the emf of cell(I0) and cell(I), the activities of lead in liquid Pb-Ag alloys can be calculated at 700, 800, 900 and 1000°C. The activities of lead and silver showed positive deviations from Raoult’s law.
(4) Several partial and integral thermodynamic quantities of Pb-Ag alloys were calculated and compared with those of other authors.抄録全体を表示PDF形式でダウンロード (744K) -
増本 量, 比内 正勝, 村上 雄悦1975 年 39 巻 11 号 p. 1127-1131
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーNi-Fe-Nb-Cr alloys were heated in hydrogen atmosphere at 1150°C for 3 hr and then cooled at rates of 0.75∼300°C/hr from a temperature above the order-disorder transformation point. The highest values of 105000 in initial permeability and 420000 in maximum permeability were obtained for the alloy of 79.80%Ni, 11.22%Fe, 8.03%Nb and 0.95%Cr when cooled at the rate of 30 and 50°C/hr, respectively. The electrical resistivity and Vickers hardness of the alloy when cooled at the rate of 30°C/hr were 80.0 μΩ-cm and 199 respectively. The high permeability Ni-Fe-Nb-Cr alloys showed very low values of the magnetostriction constant.抄録全体を表示PDF形式でダウンロード (400K) -
大石 敏雄, 橋本 高志, 森山 徐一郎1975 年 39 巻 11 号 p. 1131-1136
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーElectrochemical measurements have been made of the activity of oxygen in liquid copper alloys with a small amount of silver and antimony in the temperature range of 1100∼1150°C. The galvanic cell used was
(This article is not displayable. Please see full text pdf.)
From these experimental results, it was found that the activities of oxygen in liquid copper were decreased by the addition of antimony but a little increased by the addition of silver.
The relations between the activity coefficients of oxygen in liquid copper alloys with silver and antimony and the mole fractions of those alloying elements were represented as follows:
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小野寺 龍太1975 年 39 巻 11 号 p. 1136-1145
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーMany theoretical studies on ductile fracture in tension, except Thomason’s work, have been concerned with void growth rather than fracture conditions. In this paper Thomason’s internal necking theory was extended to the case in three dimensions and to calculate the area of the region which has enough density of voids to occur void coalescence by internal necking. Here “the deformation by internal necking” means that a thin column, sandwitched between rigid regions, is stretched to the axial direction with no reduction of its area because of the expansion of voids included in it. The stress necessary for such deformation, PV⁄SV (PV: load on the column, SV: area of it), which is raised by the constraint of the rigid region and lowered by the decrease in true area by the existence of voids, was able to be expressed as a function of volume fraction of voids in the column, vV and yield stress, Y using the theory of plasticity; PV⁄SV=Y\left(\dfrac34(1−vV2)+\dfrac16ln\dfrac27256vV3\ ight). If PV⁄SV is smaller than the tensile stress in the rigid region, Y+σr, the deformation by internal necking will occur. Here σr is the given radial stress. So, under a radial stress, vV necessary to occur such a deformation can be calculated from these equations.
Next, to calculate the area of the region, SV, in which the volume fraction of voids exceeds vV, it was assumed that all voids have column shape (radius: ρ, length is infinite), having its axis parallel to the tension axis, and the number of voids in an arbitrary small area of a specimen obeys Poisson’s distribution. Under these assumption SV could be expressed as a function of S⁄πρ2, v and vV, where S and v are the cross-sectional area and mean volume fraction of voids of a specimen, respectively.抄録全体を表示PDF形式でダウンロード (759K) -
小野寺 龍太1975 年 39 巻 11 号 p. 1145-1152
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーIt has been considered that ductile fracture of metal in tension occurs by void coalescence. It has been reported in the preceding paper that (1) the volume fraction of voids, vV, necessary to cause void coalescence by internal necking is given as a function of radial stress, σr, and (2) the area, SV, of the V region in which the volume fraction of voids exceeds vV can be expressed as a function of S⁄πρ2, v and σr, where S is the cross-sectional area of a specimen, ρ is a radius of void and v is the mean volume fraction of voids of a specimen.
This paper describes the area of the strain hardening region H, which is considered to surround the V region, and the equation for the condition of ductile fracture. A criteria of fracture was considered to be ΔPV+ΔPH≤0, where ΔPV(=SV\left{\dfrac∂Y∂ε\left[\dfrac34(1−vV2)+\dfrac16ln\dfrac27256vV3\ ight}−Y\left(\dfrac32vV+\dfrac12vV\ ight)\ ight]\dfracδh, refer to the preceding paper) and ΔPH are the increments of the load on the V and H regions after small deformation. (Y: yield stress, δ: displacement, h: a half height of the V regon equal to ρ⁄\sqrtvV)
To calculate ΔPH, it is assumed that (1) the strain in the H region varies in inverse proportion to the distance from the V region (i.e. strain concentration is relieved with distance) and (2) the distance from the center of the V region to the outer border of the H region in a certain direction is equal to the one which would move from the center of the V region before impinging on a void in the H region. Under these assumptions ΔPH was expressed as follows: ΔP_H = (1+σ_r/Y) \frac∂Y∂ε\left{\fracπ^2ρv+((S_V/π)^1/2-h) ∫_0^2 π ln\left(1+\fracπρ2vh ln\frac2 π2 π-θ\ ight)d θ\ ight}δ.
From the above equations, the condition of ductile fracture could be expressed as a function of v, σr, S⁄πρ2 and the relative strain hardening ratio (∂Y⁄∂ε)⁄Y.
The theoretical results were in approximate agreement with experiment reported previously.抄録全体を表示PDF形式でダウンロード (630K) -
成田 敏夫, 西田 恵三1975 年 39 巻 11 号 p. 1152-1160
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーConcentration profiles of nickel in the (Co, Ni)O scales grown on the Co-low Ni alloys (0.45, 2.46 and 7.23 wt%Ni) over the temperature range from 1000 to 1300°C were determined by means of EPMA and then analyzed according to the analytical equation after Wagner and the differential equations after Dalvi and Coates.
By making use of both computation methods, the concentration profiles similar to the observed ones were obtained, but an agreement between them was found to be insufficient in the inner part of the scale. The values of P(DNi⁄DCo) and n(PO21⁄n) were determined as a result of the present analytical method and found to be within the range reported in the literature. These values of P and n depended on all parameters, in particular, strongly on ξ′ (NiO content at the alloy-scale interface) and k′(=k⁄DCo0), respectively. In contrast with the presentation by Dalvi and Coates, both P- and n-values changed with NiO content in the oxide.
The mass balance equations at both scale interfaces were used to judge the validity of the numerically obtained solutions. The resulting solutions were unsatisfied with the mass balance equation at the scale-gas interface. Therefore, it was concluded that the perfect solutions could not be obtained by using the equations by Dalvi and Coates. This result may be ascribed to the changes of the P- and n-values with NiO content in the oxide.
On the other hand, the equation by Wagner is suitable for an approximate estimation of cation distribution and cation diffusivities in oxide scales because of its simplified form.抄録全体を表示PDF形式でダウンロード (693K) -
上田 修三, 綿引 純雄, 藤田 広志1975 年 39 巻 11 号 p. 1160-1168
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe formation and growth processes of twins and ε-phases in Fe-1%C-13%Mn (A) and Fe-0.35%C-20%Mn (B) alloy with low stacking fault energies have been studied under various tensile conditions. The results obtained are summarized as follows: (1) The stress at the beginning of plastic deformation is higher in alloy A than in alloy B, but the work hardening rate is contrary to this. (2) In both alloys, strain-time curves show stepped flow owing to Lüders-band like deformation. In load-time curves, the load gradually increases and repeating of sharp drops is caused by the occurrence of deformation twin in alloy A and that of ε-phase in alloy B. Both the height and frequency of these load drops are remarkably higher in alloy A than in alloy B. (3) In the temperature range from 70° to −70°C, the flow stress increases and the amount of load drop decreases with decreasing temperature in both alloys. (4) Within a strain rate range between 2.8×10−3 and 2.8×10−5 sec−1, not only the flow stress but also the amount and frequency of load-drop in serrated flow increase with decreasing strain rate in both alloys. Namely the flow stress shows a negative strain-rate dependence.抄録全体を表示PDF形式でダウンロード (1671K) -
飯田 孝道, 森田 善一郎, 竹内 栄1975 年 39 巻 11 号 p. 1169-1175
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーBy use of the capillary method, viscosities of pure liquid metals, i.e., Ga, In, Sn, Bi, Pb, Cd, Zn, Sb, Ag, Cu, have been measured from thier melting points to about 1100°C, with an accuracy of about ±0.5%.
The present experimental results are roughly in agreement with values calculated from Andrade’s equation for viscosities at the melting points. The temperature dependence of measured viscosities of these metals can be represented approximately by a simple exponential formula of the Arrhenius type over only a small temperature range, but this is not always the case over a wide temperature range.
It has also been shown that for these metals simple empirical relationships exist between the apparent activation energy of viscosity and the melting point.
The temperature dependence of viscosities of liquid metals was possible to be divided into two groups, normal metals and semi-metals, in the vicinity of the melting point.
It seems that this classification can be related to differences in structure factors of these two groups of liquid metals.抄録全体を表示PDF形式でダウンロード (596K) -
日野 光久, 阿座上 竹四, 亀田 満雄1975 年 39 巻 11 号 p. 1175-1181
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーVapor pressure of antimony in liquid antimony-silver and antimony-gold alloys have been measured by using the transportation method between 1000 and 1200°C from 10 to 90 at%Sb.
The vapor pressure of each of gaseous species such as Sb, Sb2 and Sb4 was calculated for pure antimony and several liquid alloys from the data obtained in the present work and the available data on the equilibrium among these gaseous species.
Activities of antimony were determined from the vapor pressures of antimony, while those of silver and gold were derived by the Gibbs-Duhem integration. Activities of each component exhibit considerable negative deviations from Raoult’s law except activities of antimony which show positive deviations in the Sb-rich region. Activity curves of antimony at various temperatures show a crossover point at about 75 at%Ag and 53 at%Au in the respective systems, and they approach Raoult’s law with increasing temperature in the Ag or Au richer side from these compositions. At these points, the partial heat of mixing of antimony, Δ‾HSb, shows anomalous behavior that changes from negative to positive with increasing antimony content in alloys.抄録全体を表示PDF形式でダウンロード (579K) -
昆 謙造, 佐藤 昭規, 大谷 南海男1975 年 39 巻 11 号 p. 1182-1187
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe stress corrosion cracking (SCC) test of Al-4%Cu single crystals was firstly carried out at various potentials in 5.7%NaCl+0.3%H2O2 solution, and secondly the SCC test of Al-4%Zn single crystals was carried out without applying potential in 5.0%NaCl+0.5%HNO3+0.3%H2O2 solution. The characteristics of SCC were analyzed by the mechanochemical mechanism proposed by Ohtani and Hayashi previously. The results obtained are as follows:
(1) SCC of Al-4%Cu single crystals occurs due to preferential attack along (100) traces at any anodic potential. Fracture time decreases exponentially with an increase of potential.
(2) SCC of Al-4%Zn single crystals occurs along (100) traces at the stress region below the yield point, but the orientation of cracking is not clear in the stress region above the yield point.
(3) The stress dependence of cracking propagaion period for both single crystals is explained by a mechanochemical model in which the dissolution process at the tip of crack is rate determining.
(4) There is a relation, i∝t, between the dissolution current (i) of newly created slip plaines at the tip of crack and time (t).
(5) ε1⁄2⁄t (ε: strain) is nearly proportional to applied stress (σa). This means that the mechanochemical model mentioned above is valid for the SCC of both aluminum alloy single crystals.抄録全体を表示PDF形式でダウンロード (560K) -
山田 銑一, 根岸 成和, 小松 登1975 年 39 巻 11 号 p. 1187-1194
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーHot extrusion was used to make multi-layer clad steel bars with annual ring-like section structure, interlaminated with ductile ferrite and strong martensite steel layers. The mechanical properties of these clad steels were investigated.
(1) The improvement in tensile strength (σc) was affected mainly by the layer thickness, as shown by the following equation.
(This article is not displayable. Please see full text pdf.)
(2) Comparison was made between these clad steels and SCM 4 steels quench-tempered to the same strength level. In tensile behavior, elongation was almost equal for both materials, but a smaller reduction of area was observed with the clad steels. In the strength range of 100∼150 kg/mm2, the clad steels provided higher impact strength. It was found from the impact load-time curves that maximum load was higher with SCM 4 steels, while the time to fracture was longer with the clad steels.
(3) Lower brittle-ductile transition temperature was observed for the clad steels with a thinner layer of either the ferrite or martensite phase.抄録全体を表示PDF形式でダウンロード (1045K) -
安中 嵩, 荒木 透1975 年 39 巻 11 号 p. 1194-1199
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe effect of prior austenite grain size on fracture toughness and fracture modes has been studied by means of fracture toughness testing and electron microscopy in an aged Fe-18Ni-2Al alloy, in which the stress is concentrated at the grain boundary due to the piling-up of dislocations.
In this study, there was a linear relationship between stress intensity factor at the initiation of slow crack growth which preceded rapid crack propagation and reciprocal of prior austenite grain diameter. Fracture mode depended on the ratio of plastic zone size rY=K2⁄4\sqrt2πσY2 to grain diameter d. The fraction of brittle fracture surface increased with decreasing rY⁄d and predominant fracture mode was intergranular when rY⁄d<1⁄3. Slow crack growth is attributed to the increase in fraction of ductile fracture surface with increasing rY⁄d.
KIC was increased with decreasing grain size, and a linear relationship existed between GIC and the fraction of the ductile fracture surface. These results, particularly the relationship between grain size and the stress intensity factor necessary to initiate slow crack growth are discussed.抄録全体を表示PDF形式でダウンロード (664K) -
山田 俊宏, 佐々木 敏美1975 年 39 巻 11 号 p. 1199-1204
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe wear characteristics of the hardened steels and the stress induced in the sliding surface were examined as a function of the hardness of martensite in the case of similar metal contact. The wear tests were carried out under the dry condition in air using a Pin-and-Disk type machine. The hardness of the quenched specimens which contained nearly equal amount of Si and Mn changed from Hv 480 to Hv 780 in proportion to the carbon content. These quenched specimens were examined without being tempered so that the factors such as the presence of precipitated carbides were excluded.
It was found that the wear mechanism was that of mild wear, and the wear characteristics changed with the experimental conditions, especially with the sliding speed. In the condition that the surface temperature was low, the wear rate decreased in proportion to the increase in hardness in the range between Hv 480 and Hv 650, but a further increase in the hardness did not contribute to the decrease in the wear rate. On the other hand, in the condition that the increase in sliding speed is accompanied by temperature rising in the surface, the relationship between the wear rate and the hardness became complicated and the wear rate rarely decreased with the increase in hardness.
The compressive stress thus induced in the sliding surface in the condition where the maximum compressive stress was generated, was varied with the measuring direction and the stress in the direction perpendicular to the sliding direction was larger than in the parallel direction. Moreover the surface stress was varied from −60 to −115 kg/mm2 with the hardness. It was found that the wear rate decreased with increasing compressive stress in the sliding surface. It was also suggested that a certain colleration exists between the wear rates and the stress in the sliding surface.抄録全体を表示PDF形式でダウンロード (576K) -
志賀 千晃, 藤田 英一, 木村 匡克1975 年 39 巻 11 号 p. 1205-1210
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe Mössbauer spectrum of Fe57 in the low temperature martensite phase of Fe-3 wt%Mn-1.6 wt%C alloy exhibits a new component, as well as in the martensite of iron-carbon and iron-nickel-carbon alloys, which arises from the Fe57 atoms adjacent to the carbon atoms in the tetrahedral interstices. Changes in the Mössbauer spectrum and electrical resistivity during the tempering of freshly formed martensite are observed and the following conclusions are obtained with respect to the movement of carbon atoms in the martensite structure during and after the martensitic transformation:
(i) In the martensite freshly formed at low temperatures, carbon atoms occupy the tetrahedral and octahedral interstices with nearly equal populations. X-ray diffraction data so far obtained can be explained by this model.
(ii) During the tempering the carbon atoms in the tetrahedral interstices jump to the octahedral intertices, giving rise to the changes of electrical resistivity, Mössbauer spectrum, and diffraction lines.
(iii) Around room temperature a small fraction of carbon atoms still remains at the tetrahedral sites when the carbon content is high, and at the same time clustering of carbon atoms associated with their long range migration presumably takes place.抄録全体を表示PDF形式でダウンロード (553K) -
片山 巖, 青木 松秀, 幸塚 善作1975 年 39 巻 11 号 p. 1210-1214
発行日: 1975年
公開日: 2008/04/04
ジャーナル フリーThe e.m.f.’s of the following galvanic cell with a ZrO2+CaO solid electrolyte have been measured between 950 to 1150°C in the entire composition range of Co-Mo alloys.
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\ oindentThermodynamic functions were derived from the results.
Activity of molybdenum exhibited positive deviation from Raoult’s law and activity of cobalt exhibited very weakly negative deviations in the α-solid solution. Activities of both components changed remarkably with composition in the μ-phase and changed slightly in the θ, κ and σ-phases. Integral molar free energies of formation of the alloys showed minimum values in the μ-phase.抄録全体を表示PDF形式でダウンロード (384K)
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