巻号一覧
40 巻, 6 号
選択された号の論文の17件中1～17を表示しています
- |<
- <
- 1
- >
- >|
-
田中 学, 宮川 大海, 坂木 庸晃, 藤代 大1976 年 40 巻 6 号 p. 543-551
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe precipitation behavior of 21-4 N austenitic valve steels, in which the grain boundary reaction is apt to occur owing to the high concentrations of carbon and nitrogen, has been investigated at various aging temperatures ranging from 600 to 1050°C. At higher temperatures above about 850°C, the grain boundary reaction preceded the general precipitation occurred in the interior of grains and its rate was fast. However, it slowed down with decreasing temperature and only the general precipitation occurred below about 700°C.
In order to study the driving force of the grain boundary reaction, the pre-aging was applied at 700°C to the solution treated steels prior to higher temperature aging. The grain boundary reaction took place at a much slower rate during aging at higher temperatures even in short time pre-aged steels because of the decreased supersaturation in the austenite matrix and the increased pinning force acting on the reaction front caused by finely dispersed particles due to pre-aging. It was also found that in the pre-aged steels the grain boundary nodules ceased to grow at higher supersaturation as a result of the increased pinning force for growth. For the same reason, the grain boundary reaction was considerably suppressed by cold working after the solution treatment. As regards to the effect of the cooling procedure from the solution temperature, a higher growth rate of the reaction was observed in air-cooled steels than the water-quenched ones.
A small addition of phosphorus provided the sites for homogeneous precipitation and consequently very fine precipitates were uniformly formed in the matrix in phosphorus-containing steels. In phosphorus-containing steels, however, the observed growth rate of the reaction was somewhat higher than that in steels of standard composition. It was suggested that in phosphorus-containing steels an additional driving force caused by coherent precipitation strain had a strong influence on the rate of the reaction.抄録全体を表示PDF形式でダウンロード (1268K) -
菅原 英夫, 小西 憲治1976 年 40 巻 6 号 p. 551-558
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーMeasurements of anodic polarization in 1N-H2SO4 and pitting corrosion in 0.1M-NaCl solution were performed on the samples of 13∼52%Cr-Fe alloys which were aged for 0∼5000 hr at 475°C. The most marked change is a separation of critical passivation potential Ep, which separated into Ep−1 and Ep−2 with 1000 hr or longer aging. Both the critical current for passivation icrit−1 at Ep−1 and current in the transpassive region decreased with increasing aging time, while icrit−2 at Ep−2 and the current in the passive region increased with aging time. The critical pitting potential of Fe-Cr alloys was shifted to an active value with increasing aging time and approached that of unaged 13%Cr alloy. In 13∼31%Cr-Fe alloys the sensitization was observed after 300∼500 hr aging at 475°C. The degree of sensitization is severe in the 13%Cr alloy and decreases with increasing Cr level. Microscopic examination as revealed by potentiostatic etching method shows that intergranular attack and pitting corrosion occur around the grain boundary. All of the property changes studied can be interpreted by assuming the formation of Cr-rich ferrite.抄録全体を表示PDF形式でダウンロード (1373K) -
三輪 敬之, 小野 秀隆1976 年 40 巻 6 号 p. 559-564
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe Ac3 (α→γ) transformation behavior on super-rapid heating up to 106°C/sec and the isothermal transformation on heating at various temperatures over Ac3 were investigated for a high purity iron using newly designed apparatuses.
The main results obtained are as follows:
(1) The Ac3 transformation temperature at a rate of 106°C/sec in a vacuum of 10−6 Torr and in air was determined by a PbS cell heat radiator. It was detected that the Ac3 point at each heating rate in vacuum is higher than in air.
(2) The Ac3 transformation temperature rises above the equilibrium temperature with increasing heating rate up to 106°C/sec. The Ac3s (transformation start) temperature is almost independent of the heating rate, whereas the Ac3f (transformation finish) temperature rises up to around 1350°C in vacuum at the heating rate of the order of 105°C/sec.
(3) The α-γ isothermal transformation process was continuously observed by measuring the change in electric resistance. It was considered that α→γ transformation in high purity iron might proceed intermittently by a diffusionless mechanism.抄録全体を表示PDF形式でダウンロード (540K) -
時沢 貢, 堂田 邦明, 室谷 和雄1976 年 40 巻 6 号 p. 564-571
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe hot workability of feather crystallite (F.C.) ingots and granular crystallite (G.C.) ingots was examined by dynamic and static tests to clarify the relation between the cast structure and the workability. The results obtained are as follows:
(1) Load-elongation curves obtained by the tension test showed a maximum at about 0.3% of elongation. When the working temperature was about 500°C, the flow stress σ0.3% was not so different from each other, but elongation was extremely different.
(2) The resistance to compressive deformation in the heat flow direction of F.C. ingot was the lowest of all directions, and that of G.C. ingot was higher than F.C. ingot.
(3) The speed of extrusion products through die bearing at a constant pressure in the heat flow direction of F.C. was the fastest and that of G.C. ingot was the slowest.
(4) When the F.C. ingot was extruded in high-pressure, the feather crystallite structure changed into granular grain structure, and the mechanical properties of extrusion products were the same as those of G.C. ingot.抄録全体を表示PDF形式でダウンロード (878K) -
池田 徹之, 西 成基1976 年 40 巻 6 号 p. 571-578
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe precipitation process in a supersaturated Al-3%Mn alloy solidified rapidly from the liquid state is very complex and it has been recognized that Al6Mn, G, G′ and G″ phases are its decomposition products. Further, impurity elements iron and silicon have significant effect on the precipitation process of precipitating phases containing manganese. Accordingly, using Al-3%Mn alloy, the phase decomposition process of its supersaturated solid solution were examined. The experimental methods used were measurements of hardness and lattice parameter, and analyses by X-ray diffraction and EPMA. The results obtained were as follows:
(1) Considerable age-hardening of the supersaturated solid solution was induced by heating for a long time at 325∼350°C.
(2) At aging temperatures below 550°C, precipitating phases containing manganese were G, G′ and G″ phases and, above 550°C, Al6Mn and G′ phase.
(3) Impurity elements iron and silicon precipitated as the Al-Fe binary compounds or the ternary compounds and these phases had a significant effect on the nucleation and growth speed of the precipitating phases containing manganese.
(4) The variation in lattice parameter during isothermal heating was of the continuous type, but the lattice parameter was separated into two values in the early and middle stages of the precipitation process.抄録全体を表示PDF形式でダウンロード (818K) -
池田 徹之, 西 成基1976 年 40 巻 6 号 p. 578-584
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe precipitation-decomposition process of a supersaturated Al-3%Mn solid solution, obtained by solidifying rapidly from the liquid state, is complicated but is of great interest as discussed in the previous report. In this paper, the changes of lattice parameter were analyzed by applying a simple nucleation-growth model for the precipitation of the supersaturated solid solution consisting of the network structure of cylindrical cells and assuming the manganese concentration profile in the matrix. Furthermore, the precipitation process and the decomposition process in the supersaturated solid solution were investigated. The results obtained were as follows:
(1) The precipitation processes of compounds containing manganese on isothermal heating were classified by the exponent m value in the Johnson-Mehl equation, and those values were m=5⁄2 for the early stage of the precipitation-decomposition process, m=1 for the middle stage and m=1⁄2∼1⁄3 for the last stage.
(2) The decomposition process of the supersaturated solid solution progressed in diffusion zones around precipitate zones at the early stage, and at the middle stage, in the inner part of cells. At the last stage, the manganese concentration in the matrix became almost homogeneous and the decomposition progressed at all parts of the matrix.
(3) At aging temperatures above 550°C the activation energy for precipitation of Al6Mn+G′ was 40.7 kcal/mol, and below 550°C that of G+G′+G″ was 21.4 kcal/mol.抄録全体を表示PDF形式でダウンロード (623K) -
池田 徹之, 西 成基, 瀬尾 博1976 年 40 巻 6 号 p. 584-592
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーBy rapid cooling of Al-1∼5%Mn alloys from the liquid state, solidified structures showed remarkable changes with cooling rate. By lattice parameter measurements and analyses of X-ray diffraction and EPMA line-scanning patterns, the solid solubility of manganese in the matrix, crystallized compound phase in those structures and the structure distribution were examined. The results obtained were as follows:
(1) With increase in solidification rate, the lattice parameters of matrix phases decreased from 4.045 Å to the value corresponding to complete supersaturation according to the degree of supersaturation in the range of solidification rate with the occurrence of incompletely supersaturated solid solution. Other structures showed constant lattice parameters.
(2) The conditions for formation of supersaturated solid solutions and the distribution diagram of solidified structures were determined from the change of the lattice parameter.
(3) In incompletely supersaturated solid solution, a new metastable intermediate phase AlmMn (simple cubic, a0=12.727 Å) and an equilibrium phase Al6Mn were crystallized. The structure produced by the movement of the eutectic point and an equilibrium structure was Al6Mn (or Al6(Mn, Fe)). Furthermore, compound phases containing impurity elements of iron or silicon (Al6Fe, Al3Fe, α-Al12Mn3Si and α-Al-Fe-Si) were detected in those structures.抄録全体を表示PDF形式でダウンロード (1313K) -
高 武盛, 佐久間 健人, 西沢 泰二1976 年 40 巻 6 号 p. 593-601
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーIt has been pointed out by Hillert et al. in 1967 that the partition of manganese between cementite and ferrite is markedly influenced by the magnetism of ferrite, and the temperature dependence of the partition coefficient shows an abnormal deviation from the ordinary Arrehnius equation in the vicinity of the Curie temperature. This work was intended to extend their idea to the other elements, and the partition coefficient of chromium, manganese, cobalt and nickel between cementite and ferrite at 700∼500°C was measured. It was found that the partition coefficient of chromium and manganese increases considerably, and that of cobalt decreases abnormally as the equilibration temperature falls. In the case of nickel, the coefficient does scarcely show the sign of decrease contrary to the prediction from the Arrehnius equation. These findings are in good agreement with the theory proposed by Hillert et al. The partition of the elements between cementite and austenite was also studied, and a parameter ΔGMα⁄γFe representing the effect on the relative stability of ferrite and austenite was evaluated.抄録全体を表示PDF形式でダウンロード (723K) -
大森 慎一郎, 橋本 雍彦1976 年 40 巻 6 号 p. 601-605
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe e.m.f. measurements were made on the cell,
(This article is not displayable. Please see full text pdf.)
\ oindentby using a Co-B alloy containing about 20 at%B. The e.m.f. values were used in calculation of the thermodynamic properties of Co3B and Co2B. The calculated thermodynamic properties are as follows:
(This article is not displayable. Please see full text pdf.)
\ oindentand
(This article is not displayable. Please see full text pdf.)
\ oindentIn the diagram of the e.m.f. vs temperature, the intersection of a line for the system Co+Co3B with a line for the system Co+Co2B yielded a eutectoidal temperature of 845°C.抄録全体を表示PDF形式でダウンロード (629K) -
青木 顯一郎, 勝田 基嗣, 菅又 信1976 年 40 巻 6 号 p. 605-611
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThis report dealt with the additional effect of third element on deep drawing properties and ear after drawing of Al-Mg system alloy sheets.
The X-ray texture, “n” value and “r” value of tarnary alloy sheets to which very small amounts of Mn, Cr, Zr and Ti were added were measured.
The results obtained were as follows:
(1) Very small additions of Mn, Cr, Zr and Ti as third elements promoted refinement of the grain, and increased the values of tensile strength and 0.2% proof stress. Especially, the addition of Mn and Cr was effective for grain refinement.
(2) Very small additions of Cr, Zr and Ti as third elements tended to reduce deep drawing properties with an increase in alloying addition. However, Al-5.85%Mg-0.14%Mn alloy sheets did not reduce the deep drawing properties but increase the strength.
(3) The ear emergent direction and earing ratio were fairly compatible with the “r” value, and with an increase in the addition of the third element, the earing ratio appeared to be reduced.
(4) As to recrystallization texture, (310)[\bar132] and (001)[310] appeared strongly and all ears emerged in a 45° direction.抄録全体を表示PDF形式でダウンロード (554K) -
橋本 健紀, 辻本 得蔵1976 年 40 巻 6 号 p. 611-617
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーPrecipitation behaviour in Ni-8%Ti and Ni-10%Ti alloys aged at 550∼950°C has been studied by means of transmission electron microscopy and X-ray diffraction. The results are summarized as follows:
(1) Stable η-phase plates are formed directly from the supersaturated solid solution at high temperature aging, while metastable α2-phase cuboidal particles appear at the early stage of aging at low temperatures. The latter process is observed at temperatures less than 675°C in the Ni-8%Ti alloy and at temperatures lower than 940°C in the Ni-10%Ti alloy.
(2) The distribution of α2-phase particles is rather regular on aging at temperatures lower than 575°C in the Ni-8%Ti alloy and at temperatures lower than 900°C in the Ni-10%Ti alloy, while the distribution is at random at higher temperatures.
(3) The lattice parameter of α2-phase changes to smaller values as the aging temperature increased.
(4) From the above results, the upper limit line of α2-phase precipitation, Ni-rich solvus line of α2-phase and the upper limit line of modulated structure formation are drawn on the Ni-rich side of the Ni-Ti diagram.
(5) X-ray side-bands are observed at the stage where the regular array of α2-phase particles is formed.抄録全体を表示PDF形式でダウンロード (1182K) -
平野 秀朗, 高野 道典, 下平 三郎1976 年 40 巻 6 号 p. 618-624
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe mechanism of a stress-corrosion cracking of Al-4.57%Zn-1.35%Mg and Al-4.43%Zn-1.34%Mg-0.13%Cu alloys in 3%NaCl aqueous solution was investigated electrochemically and metallurgically.
A constant load test and a constant strain rate test were carried out to determine the effect of aging treatments on a susceptibility to stress-corrosion cracking. The results obtained from these tests showed that both alloys aged at 120°C for 24 hr became most susceptible to stress-corrosion cracking, which was accelerated by an anodic polarization or a cathodic polarization of −1000 mV (SCE). In the former polarization, stress-corrosion cracking occurred by a stress-assisted intergranular corrosion, and in the later condition it took place by a cooperative actions of pitting which produced by a selective dissolution of high density η′-particles along grain boundaries and the stress concentration wherein. Under the cathodic polarization from −1200 mV to −1800 mV (SCE), the specimens suffered general corrosion, and stress-corrosion cracking did not occur. Both anodic and cathodic polarization curves showed a good relation to aging treatments but no relation to stress-corrosion cracking.抄録全体を表示PDF形式でダウンロード (1177K) -
清重 正典, 堺 邦益, 喜多 清1976 年 40 巻 6 号 p. 625-631
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーIn most industrial metals and alloys, a small amount of minor elements are contained as additional elements or impurity. However, it is impossible for the present to predict how these elements behave against the segregation behavior of major elements. The authors have investigated the segregation tendency of third elements, Mn, Si, Fe, Cr and Al, in Ni-30%Cu alloy.
The results obtained are as follows:
(1) The dendrite arm spacings of unidirectionally solidified Ni-30%Cu alloys were hardly affected by a small addition of third element, while the morphological aspects of the dendrite were varied.
(2) Among the minor elements studied, Mn and Si segregated with solute Cu, but Fe, Cr and Al segregated with solvent Ni.
(3) It is considered that the tendency of segregation of minor elements related with the relative valency effect, since it is possible to explain this tendency by the difference in solubility between solvent and solute.
(4) It is found that the segregation ratio of Cu was increased by the addition of a minor element which had a tendency to segregate with solvent Ni.抄録全体を表示PDF形式でダウンロード (713K) -
田上 耕司, 仙場 謙次, 岡崎 謙二1976 年 40 巻 6 号 p. 632-637
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーDifferential strain rate, strain rate cycling and stress relaxation tests were carried out to obtain the activation volume for dislocation motion in sintered pure molybdenum over the temperature range from 292 to 550°K. By comparing the apparent activation volumes deduced from these various methods with each other, the analytical method to obtain the true activation volume, V0*, was discussed. V0* could be obtained from the stress relaxation test by extrapolating the relaxation time, t, to t=0, i.e. V0*=limt→0[2kT∂ln(−\dotσ)⁄∂σ]T. VF* obtained by Feltham’s analysis of the relaxation data must, however, be corrected in the variation of the mobile dislocation density during relaxation to obtain V0*.
In the temperature range below 420°K, V0* was found to be less than about 100 b3 and independent of the plastic strain, indicating that the rate controlling mechanism is thermally activated overcoming of the Peierls potential by nucleating a double kink. Dislocation velocity-stress exponent, m*, was also obtained to be 9.0, 6.6 and 6.0 at 292, 350 and 420°K, respectively, from Gupta and Li’s analysis of the relaxation data. By using two parameters, V0* and m*, the thermal component of the flow stress, σ∗, could be calculated from the relation of σ*=m*kT⁄V*. The σ*−T relation showed a good agreement with Friedel’s formula, which led to the Peierls stress of τp0=58 kg/mm2.抄録全体を表示PDF形式でダウンロード (496K) -
大河内 春乃, 高橋 且征, 鈴木 俊一, 須藤 恵美子1976 年 40 巻 6 号 p. 638-644
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe optimum recasting condition has been examined and the electrolytic iron dilution method has been developed, by which the samples can be analysed, even if their quantities are not enough for the usual method or adequate standard samples are unable to be obtained in the case of high alloy steels.
The amounts of manganese loss is related with the melting time and the permitted melting time has been increased with the increase in the amounts of the aluminum deoxidant. The argon flow rate also influences the loss of manganese and more than 4 l/min and 2 l/min of argon are acquired in the case of 0.3 and 0.7% aluminum deoxidant, respectively. It is observed that the amounts of vaporization of iron, manganese and chromium are more restrained in the case of the latter than the former. Added aluminum is rapidly decreased when samples are heated for 100 sec or longer. From these results, it is considered that aluminum has the effect of decreasing the partial pressure of other elements as well as that of deoxidation.
In order to prevent crack at recasting samples containing high carbon such as pig iron, a longer heating time after melting and a shorter delay time until casting after heating are desirable.
Low alloy steels are recast with electrolytic iron at dilution rates of (1:1)∼(1:4). Carbon, silicon, manganese, nickel, chromium and molybdenum have been determined successfully. Only vanadium gives low analytical results at higher dilution rates.
Stainless steel and heat resisting supper alloy have been recast at dilution rates of (1:10)∼(1:30). Nickel, chromium and manganese give good results.抄録全体を表示PDF形式でダウンロード (647K) -
浅岡 憲三, 三浦 維四1976 年 40 巻 6 号 p. 644-649
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe finite element method was used in the micro-mechanical calculations of the tensile behavior of a discontinuous off-axis (the loading direction is at an angle to the fiber axis) fiber composite alloys. The effect of the off-axis on the strength of the composite alloys was also discussed.
The mechanical properties of the matrix and the fiber were assumed to be those of aluminum and high Young’s modulus materials such as precipitates, metal fibers and whiskers. The ratio of their Young’s moduli, Ef⁄Em, was taken as 5. The fiber reinforcement was considered to be perfectly bonded in the matrix. The shear stress distributions at the matrix fiber interface, the stress distributions in the fiber, and the stress distributions in the matrix were investigated in various off-axis tensile stress directions.
Three possible failure mechanisms in a composite alloy with discontinuous unidirectionally-aligned fibers are postulated, viz. fiber failure at the maximum principal stress in the fiber, matrix fiber interface failure in shear at the maximum shear stress at the interface, or matrix failure at the normal stress. And the opperative mechanism was dictated for the strength of the composite with off-axis φ, which was compared with the criterion of the continuous fiber reinforced composite proposed by Kelly-Davies.
The results of these calculations showed that the interface might be fractured under a low off-axis tensile stress because of the shear stress acting on the fiber end. Thus the critical off-axis angle φcrit was smaller than that of continuous fibers. For the strengthning with discontinuous fiber, it is therefore essential to align the fiber in the tensile direction and also to prepare a composite alloy with a strong interface.抄録全体を表示PDF形式でダウンロード (461K) -
大西 敬三, 干葉 隆一, 手代木 邦雄, 加賀 寿1976 年 40 巻 6 号 p. 650-656
発行日: 1976年
公開日: 2008/04/04
ジャーナル フリーThe embrittlement tests of high strength steels with yield strength of 116 to 150 kg/mm2 were performed under a high pressure gaseous hydrogen atmosphere at a room temperature.
The results obtained are summarized as follows:
(1) The high strength steels such as Medium C-Ni-Cr-Mo Steel obviously shows embrittlment under gaseous hydrogen atmosphere at room temperature. The extent of embrittlement increased with hydrogen pressure in such that the notch tensile strength decreased remarkably with increasing hydrogen pressure up to 50 kg/cm2, while the degradation became rather smaller in the pressure range of 50 to 100 kg/cm2.
\ oindent(2) The degradation of the notch tensile strength due to gaseous hydrogen appeared to be closely associated with the stress concentration factor; that is, with its increase, the notch tensile strength was reduced.
(3) The fracture pattern that failed under high pressure gaseous hydrogen was varied with the depth; quasi-cleavage fracture beneath the notch, then intergranular fracture and finally to ductile fracture. Intergranular fractured area increased with embrittlement.
(4) Hydrogen analysis for the failed test pieces showed that the residual hydrogen content in the embrittled materials was larger than that for the non-embrittled.抄録全体を表示PDF形式でダウンロード (1163K)
- |<
- <
- 1
- >
- >|