Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 25 , Issue 11
Showing 1-16 articles out of 16 articles from the selected issue
  • Hideo Tajiri, Masaharu Matsubara, Koshi Katayama, Tadao Nakada
    1961 Volume 25 Issue 11 Pages 685-688
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Specimens of α+β brass of 59.98%Cu, of 3 mm×10 mm×10 mm size cut out from an ingot of 30 mm×90 mm×180 mm size and polished but not etched were studied under a high-temperature microscope, to examine continuously the changes in structure under elevated temperature, beginning at room temperature and rising to 780°C. The results obtained were as follows: (1) Unevenness appeared in the β-grains at 400∼550°C, while the α-grains grew larger, the volume of α feaching the maximum at 550°C (2) α began to be absorbed by β in the vicinity of 600°C (3) At constant temperature, the larger was the absorption of α by β, the longer the holding time, and the absorption was the larger, the higher the temperature. (4) In the β-monophase range under high temperature, new β-grain boundaries were formed crossing the original boundaries, and while making vehement translocations, steadily went on stabilizing.
    Download PDF (2251K)
  • Tomo-o Sato, Yen-Chieng Huang, Yutaka Kondo
    1961 Volume 25 Issue 11 Pages 689-693
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The metastable phases produced during heat treatment in Ti alloys always exert an influence upon their properties. Using some Ti-rich alloys in the Ti-Al-Mn system, the martensitic transformation temperatures of β phase during quenching have been measured by a rapid thermal analysis with a newly devised argon-gas quenching apparatus, and the processes of decomposition of the retained β and the martensite phases have been investigated by means of a dilatometer, a microhardness tester and a microscope, while tempering at a constant heating rate of 2°C/min. The Ms point drops significantly by increasing the amount of Mn but not Al. The equithermal diagram of Ms points of Ti-rich alloys of this system has been illustrated in Fig. 2. A quenched alloy consisting of retained β phase only shows a large contraction in the range from 250° to 400°C, and the hardness rises in proportion to the contraction from VHN 350 up to 570, but little change was observed in the microstructure. A quenched alloy consisting of only martensite phase with shows no perceptible change either in dilatation and hardness or in microstructure during tempering. The evidence of contraction in dilation and the hardness increase during the tempering may be due to the formation of a transition phase, so-called ω, transformed from β phase. However this phase was not determined microscopically.
    Download PDF (2389K)
  • Nakaaki Oda, Noboru Katayama, Kazue Endo
    1961 Volume 25 Issue 11 Pages 693-698
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The important effects of gas contents on the physical properties of tantalum have necessitated an accurate method for determining the gaseous impurities in the metal. In order to establish a method for simultaneous analysis of oxygen and hydrogen in tantalum, the following investigations including application of tin-bath technique for these determinations were conducted. The experiments were carried out, by means of NRC 09-1240 Type Vacuum Fusion Gas Analyzer,to obtain information on the influence of graphite chips on removal of oxygen, the desirable ratio of tin to sample, and the range of the optimum operating temperature necessary for obtained complete removal of oxygen from standard samples. By using the proposed technique, in the presence of graphite chips and under the operating temperature 1960° to 2000°C, it is possible to determine the oxygen content in the samples wrapped in about 3∼4 times their weights of tin foils. Hydrogen may be readily released from tantalum samples by the established technique because of its thermal-decomposition. It was found that the average oxygen recovery from standards is 98% and the hydrogen values were comparatively consistent with those obtained by conventional combustion method, above the lower limit(0.005 wt% of hydrogen) of determination by the latter method.
    Download PDF (1907K)
  • Tatsuro Kunitake
    1961 Volume 25 Issue 11 Pages 698-702
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The self-diffusion data in the b.c.c. phase of Fe-Cr alloys—the author’s data and others in the literatures—have been summarized. (1) The self-diffusion coefficients of chromium and iron, (2) the chemical diffusion coefficients, are shown as a function of composition in the temperature range from 950° to 1275°C. (3) D0 for self-diffusion of chromium has the order of 10−4 cm2/sec in pure chromium. D0 for chromium shows large variation with composition, with a maximum of 10+1 cm2/sec at about 70 at%Cr and a minimum of 10−1 cm2/sec in 30 to 40 at%Cr. The concentration dependence of D0 of the self diffusion for the iron has the same trend as for chromium, although the self-diffusion for iron has a maximum of 10+4 cm2/sec and a minimum of 10−1 cm2/sec. (4) The concentration dependence of the activation energy of the self diffusion for chromium and iron is qualitatively similar to that of D0. For chromium self-diffusion, it varies in the range from 48 kcal/g-atom (30 to 40 at%Cr) to 72 kcal/g-atom(about 70 at%Cr). For iron self-diffusion, it varies in the range from 50 kcal/g-atom to 90 kcal/g-atom. The mechanism of the diffusion in this system is discussed.
    Download PDF (1742K)
  • Satoshi Kugasa
    1961 Volume 25 Issue 11 Pages 703-707
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The effect of addition of Mo or W micro powder on the recrystallization behaviour of cold-rolled Al and Al-2%Mg alloy has been studied by means of hardness measurement and microscopy. The results obtained were as follows: (1) The recrystallization temperature in Al and Al-Mg alloy rose slightly with the increase of the amount of added Mo or W till the content reached a certain critical amount, as shown in Table 2. When the content is larger than this critical value, however, the recrystallization temperature became almost constant. (2) The size of the recrystallized grains become progressively finer with addition of Mo or W till the content of Mo or W reaches 0.3∼0.5%Mo or W in Al, and 0.05∼0.1%Mo or 0.2∼0.3%W in Al-Mg alloy. In the specimens with Mo or W of more than this content,however, the recrystallized grains are fairly fine and almost constant against the change of final annealing temperature as well as cold-rolling reduction of more than medium degree, also free of influence from the variation of the preliminary annealing temperature. (3) The recrystallization diagrams of Al and Al-Mg alloy containing Mo or W have been studied, as shown in Fig. 3,Fig. 4,Fig. 5 and Fig. 6.
    Download PDF (1734K)
  • Tsuguyasu Wada
    1961 Volume 25 Issue 11 Pages 707-711
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    A thermodynamic study was made on the shape of the γ-field in the phase diagram of iron alloys. The atomic fraction of the solute xB of the so-called allotropic phase boundary was given by
    (This article is not displayable. Please see full text pdf.)
    where ΔFA, ΔFB are the energy differences between γ- and α-phase for pure Fe and pure solute, respectively, and Δw is the difference of interchange energies between γ- and α-alloys. The shape of the allotropic phase boundary was determined by the two parameters, ΔFB and Δw. The theory was applied to Fe-Cr, Fe-Ti and Fe-Co systems, and consistencies with experimental diagrams were obtained for Fe-Cr and Fe-Co. For Fe-Ti system, extremely high values of ΔFB and Δw were required to interprete the experimental γ-loop.
    Download PDF (1536K)
  • Isao Gokyu, Hideo Abe, Tan Hashida, Susumu Takahashi
    1961 Volume 25 Issue 11 Pages 712-716
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Several Fe-Si-Al alloys containing 3 wt.%Si plus Al (including 3 wt.%Si-Fe and 3 wt.%Al-Fe alloys) were prepared by melting in air in an induction furnace. After forging and annealing, they were processed in two cold-rolling operations separated by an intermediate annealing. The following two combinations of the cold-rolling reductions and the annealing conditions were tested: (G) 65% reduction,annealing at 850°C for 1 hr in vacuum, 65% reduction, final annealing at 1050°C for 1 hr in vacuum. (W) 80% reduction, annealing at 1000°C for 1 hr in H2, 80% reduction, final annealing at 1000°C for 2 hrs in H2. The final annealing textures were examined by magnetic torque measurements and by X-ray pole-figure determinations. The following results have been obtained. (1) In all specimens, larger cube/Goss ratio in the final annealing texture was obtained by the W-process. Especially, larger cube/Goss ratio was obtained in alloys containing more than 1.2%Al. (2) The Goss texture was developed by the G-process and the effect of the inclusion inhibition on the sharpness of the Goss texture was not appreciably different in any of the specimens.
    Download PDF (1483K)
  • Hakaru Masumoto, Hideo Saitô, Yutaka Sugai, Sadashi Tezuka
    1961 Volume 25 Issue 11 Pages 716-720
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    According to the rule of the small expansibility of invar proposed previously by Dr. H. Masumoto, it was proposed that there are some invar- and elinvar-type alloys in the cobalt, iron and tungsten system, and also in the quaternary system containing nickel besides these. Thus,the thermal expansion coefficient, the rigiditiy modulus and its temperature coefficient were measured with the ternary and the quaternary alloys mentioned above in annealed state. It was found that the temperature coefficient of rigidity modulus showed its negative minimum value of −0.7×10−5 having a composition with the minimum value of 7.39×10−6 of thermal expansion coefficient in the ternary system; the figures of the curves of iso-temperature coefficient of the modulus were almost the same as those obtained previously with alloys containing cobalt, iron and chromium, cobalt, iron and vanadium, and also cobalt, iron and molybdenum with the exception that the present alloys did not show any positive value of the coefficient. Thus, it has been proved that there are some invar- and elinvar-type alloys in this ternary system as expected. When 10 per cent of nickel was added to the ternary alloys, the range showing positive temperature coefficient of the modulus began to appear. With increase of nickel content,the minimum value of the thermal expansion coefficient became smaller and the positive maximum value of the temperature coefficient of the modulus larger, and the composition at which these special characteristics were observed shifted to the side of low cobalt and low tungsten, finally reaching 36 per cent of nickel in the binary system of iron and nickel; showing the same effect as when the nickel was added to the alloys of cobalt, iron and chromium, of cobalt, iron and vanadium, and of cobalt, iron and molybdenum. These new ternary and quaternary alloys with small temperature coefficient of the modulus have been named “Tungelinvar”.
    Download PDF (1817K)
  • Runa Tsuzuki
    1961 Volume 25 Issue 11 Pages 721-723
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The zone-refining process has been applied to selenium of 99.994% purity. The theory of zone-refining is based upon the phase diagram of binary alloys. But according to recent experiments, the segregation of impurities in zone-refining process of a metal which has relatively low melting point such as In or Se cannot be explained by the rule of phase diagram. Se contains impurities whose distribution coefficients k are less than unity. Besides, Se itself is transformed by a heat treatment. So it has not been confirmed whether the application of zone-refining to Se is effective or not. The specimens of Se were refined under various conditions. The travel rates of 7, 20, 40, 58 mm/hr were chosen. The effect of zone-refining was confirmed by the radio-activation and spectrographic analysis. The results obtained were as follows. The impurities Ga, Cu, Ca, Bi and Te segregated at the starting end. The impurities Al, Fe, Mg, Mn, Sb and Si segregated at the finishing end. Se crystallized, in the cases of the travel rates smaller than 20 mm/hr, and it resulted in vitreous Se at 40 mm/hr and 58 mm/hr. Zone-refining was most effective at the medium rate. In the case of purification of binary system alloys consisting of Se and an element whose k is larger than unity, the number of zone-travels required for the effective segregation of elements which have the tendency to move towards the starting end, must be at least larger than the ratio: bar length/width of molten zone.
    Download PDF (810K)
  • Kimiko Sato
    1961 Volume 25 Issue 11 Pages 723-728
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    This experiment was done in order to elucidate the mechanism of deformation at hot-working of metals. The aluminum wires were stretched to various amounts of elongation at various temperatures and then quenched in water within 0.01 second. These specimens were annealed at various temperatures and their recrystallization on annealing was investigated. The following results were obtained. (1) The mode of deformation at hot-working and the process of recrystallization during annealing of Al wires were much different from those of α-brass wires previously reported by the author. For example,one of the three ways of softening,namely nucleation and growth process, migration of grain boundary and recrystallization in situ, was observed in Al wires. (2) The temperature of first recrystallization became higher as the working temperature of the specimen became higher and as the working degree of the specimen became lower. (3) The hot-worked specimen has a stronger tendency of abnormal grain growth than a cold-worked one on annealing, especially when it was worked at high temperature and low degree of working. (4) The results of X-ray observations corresponded well with the microscopic observations.
    Download PDF (1861K)
  • Kenichi Nakamura, Yoshimune Nakamura
    1961 Volume 25 Issue 11 Pages 728-732
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The softening appearing in drawn high-carbon steel wire when lightly cold-worked after low temperature annealing was examined. A 0.83%C piano wire subjected to patenting (980°C→500°C) at the diameter of 2.92 mm and then drawn through 2 dies to the diameter of 2.51 mm, was used as the specimen. The specimen was drawn, stretched and bended after being aged under various conditions. The tensile strength and the hardness distribution on the cross-section of the cold-worked specimen were measured. Softening was notable after 5∼10% reduction drawing and in the compression side after repeated bending and slightly after stretching by pure tension. The cause of this softening can be considered as due to dislocation escaping away from the atmosphere of carbon and/or nitrogen atoms and to a part of internal micro-stress caused by precipitates being released by slight plastic working.
    Download PDF (1418K)
  • Ken’ichi Numakura
    1961 Volume 25 Issue 11 Pages 732-736
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The magnetostriction anisotropy of hot-rolled and cast“Alfer” alloy was studied. The saturation magnetostriction is closely dependent upon the roll direction, and shows a minimum value in the direction perpendicular to that of rolling and a maximum value in a direction midway between the roll direction and the direction across it. This magnetostriction vs. roll-direction curve is varied more or less by the heating temperature. The saturation magnetostriction vs. heating temperature curve is complicated, and shows a maximum near 500∼600°C. The saturation magnetostriction shows the largest value in cast state, and, in roll state, decreases with increase of the degree of roll reduction. This tendency is more marked in the direction normal to the rolling. Furthermore, the general theoretical expression was presented for the magnetostriction of rolled b.c.c. magnetic substance, and the saturation magnetostriction in θ direction of grain-oriented polycrystalline sheet, λθ was found to be expressed as follows.
    (This article is not displayable. Please see full text pdf.)
    Where, \varphi and η are the angle between the principal direction ⟨100⟩ and roll direction in the {100} or {110} planes parallel to roll plane respectively, and h{100}, h{110} and h{A} are the fractions of grain numbers having the principal plane {100}, {110} and the others parallel to roll plane, respectively. {A} means random orientation. K{100}i and K{110}i are the fractions of above planes taking the angle of \varphi or η to the principal direction, respectively. Using the above equation and the magnetostriction constants obtained by Hall, and assuming a reasonable crystal orientation, the theoretical saturation magnetostriction was calculated. A good agreement existed between the theoretical and the experimental results.
    Download PDF (1317K)
  • Ken’ichi Numakura
    1961 Volume 25 Issue 11 Pages 736-738
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The elastic anisotropy of hot-rolled “Alfer” sheets was studied. The young’s modulus of “Alfer” sheet was found closely dependent upon the roll direction, and the Young’s modulus vs. roll direction curve showed a maximum in cross direction, another maximum in 15°(165°) direction, and a minimum in 45°(135°) direction to the roll direction. In the case of a specimen with lower degree of roll reduction, the maximum in 15°(165°) direction became gradually smaller with rise of heating temperature, and finally disappeared at higher temperature. The Young’s modulus in each direction parabolically decreased with the rise of heating temperature. Furthermore, the general theoretical expression was presented for Young’s modulus of rolled b.c.c. magnetic substance, and Young’s modulus in θ direction of grain-oriented polycrystalline sheet Eθ was found to be expressed as follows.
    (This article is not displayable. Please see full text pdf.)
    Where, \varphi and η are the angle between the principal direction ⟨100⟩ and roll direction in the {100} or {110} planes parallel to roll plane respectively, and h{100}, h{110} and h{A} are the fractions of grain numbers having the principal plane {100}, {110} and the others parallel to roll plane respectively. {A} means random orientation. K{100}i and K{110}i are the fractions of above planes taking the angle of \varphi or η to the principal direction respectively. Using the above equation and the elastic coefficients SiK obtained by the author, and assuming the same crystal orientation as in the case of magnetostriction, the theoretical young’s modulus was calculated. A good agreement existed between the theoretical and the experimental results.
    Download PDF (608K)
  • Ken’ichi Numakura
    1961 Volume 25 Issue 11 Pages 738-742
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    An extensive study on the order-disorder transformation of hot-rolled “Alfer” sheets with 12.29 per cent of aluminum was undertaken. The saturation magnetostriction in ordered state after furnace cooling showed large value, but that in disordered state after water quenching was relatively lower, and the degree of decrease reached about 60 per cent in some direction. The saturation magnetostriction after subzero quenching in liquid nitrogen stood midways between the values in the two states mentioned above. The Young’s modulus was largest after water quenching, next after furnace cooling, and smallest after subzero quenching in liquid nitrogen. The saturation magnetostriction and the Young’s modulus rose slightly when the specimens were heated at the lower temperatures 100° or 300°C after subzero quenching in liquid nitrogen. The electrical resistivity was largest after water quenching, next after subzero quenching in liquid nitrogen, and smallest after furnace cooling. The density was largest after furnace cooling, next after subzero quenching in liquid nitrogen, and smallest after water quenching.
    Download PDF (1565K)
  • Hiroyasu Mitani, Norihiko Nakanishi
    1961 Volume 25 Issue 11 Pages 742-746
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    In the previous reports, the authors tried to make T/T/T-diagrams for the β phase in Cu-Al binary alloys. It was found that the transformation β→β1, an ordering reaction, proceeded more early than the transformation β→α+γ2 at holding temperatures below Tc, and the transformation β1→α+γ2 continued subsequently. In this experiment, the authors made some investigations about the decomposition processes of the martensite phases obtained by rapid cooling. Two kinds of alloys, 10.93 wt% and 11.83 wt%Al, were obtained in the β′ condition by water-quenching from 1000°C. Specific heat measurements, X-ray diffraction tests and microphotographs, were used to make T/T/T-diagrams on tempering. As a result of the experiments, it was confirmed that the ordered region containing about 12.4 wt%Al extends with the precipitation of α at temperatures above 400°C, and this tendency decreased at tempering temperatures below 400°C. Recently R.G. Cope has reported on the tempering of martensite in Cu-Al alloys. The present authors have made comparatively discussion on the two sets of reported experimental results here.
    Download PDF (1479K)
  • Hiroyasu Mitani, Norihiko Nakanishi
    1961 Volume 25 Issue 11 Pages 746-750
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Considering the previous experimental results, it may be obvious that the ordered region containing about 12.4 wt%Al will govern the decomposition stage of β′ at tempering temperatures above 400°C, but below 400°C, this tendency will weaken immediately. In this report, the decomposition behaviors of martensite in hyper-eutectoid alloys have been investigated by means of specific heat measurements, X-ray tests, and microscopic observations. The specimens were of two kinds of hyper-eutectoid alloys containing 12.35 wt% and 12.91 wt%Al, respectively. The authors have again confirmed that the above ordering reaction appeared at the condition of Tc>Th>400°C, and on the other hand, at the condition of Th<400°C, precipitation of γ2 occurred and γ′ martensite has been decomposed into the two phases, β′+γ2. Tempering kinetics of the γ′ martensite may be interpreted according to the above results.
    Download PDF (1429K)
feedback
Top