Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 25 , Issue 10
Showing 1-17 articles out of 17 articles from the selected issue
  • Isao Tarôra, Takami Maruta
    1961 Volume 25 Issue 10 Pages 615-618
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The age-hardening phenomena in 0.3%Zr-Cu base ternary alloys have been studied in order to improve the mechanical properties of Cu-Zr alloy. As the third elements, Fe,Ni,Co,Cr,Si,Al and Be were selected. The results obtained have been summarized in the following: The aging effects on hardness and tensile strength of these alloys are more remarkable than that of Cu-Zr alloy. The maximum values of the properties obtained by aging are presented in Fig. 9 as compared those of Cu-Zr alloy. The electrical conductivity and the mechanical properties of Cu-Zr-Cr alloy are improved markedly, so this alloy is very promising as a high-strength copper alloy with good electrical conductivity.
    Download PDF (1141K)
  • Yûnoshin Imai, Ikuo Mori
    1961 Volume 25 Issue 10 Pages 618-622
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The residual stresses in the two commercial steels after water,oil and subzero quenching and tempering were studied. The steels containing 1%C, and 1%C, 1%Cr and 1%Mo were used. The form and dimension of residual stresses were decided almost according to the thermal career from heating temperature of hardening to room temperature, and not affected by subzero treatment while the hardness was decidedly increased. A marked decrease of residual stresses was seen by the decomposition of retained austenite but they did not disappear completely even by tempering at 550°C for 1 hours.
    Download PDF (1557K)
  • Jirô Watanabé
    1961 Volume 25 Issue 10 Pages 623-626
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The fatigue properties have been studied at room temperature, using a cantilever rotating-bending machine, on zinc single crystals with [0001], [10\={1}0] and [11\={2}0] orientations and on zinc polycrystals having the grain size of 130∼310 grains/cm2. The S-N curve representing the relation between the maximum alternating bending stress and the logarithm of the number of cycles to fracture is linear for single crystals as well as for polycrystals,but its slope is the greatest for polycrystals and becomes less in the order of [11\={2}0]≅[10\={1}0] and [0001] single crystals. Particularly, the S-N curve for [0001] crystals lies nearly parallel to the abscissa, showing that the fatigue failure occurs in a very narrow stress range, above which they cleavage-fracture along the (0001) plane immediately after the load was applied. This supports the idea that brittle crystals show little fatigue. The fatigue strengths of [11\={2}0] and [10\={1}0] crystals are nearly the same and that of polycrystals is independent of the grain size in the range of 130∼310 grains/cm2. The endurance limit, as defined conveniently as the fracture stress at 107 cycles, is 2.0 kg/mm2 for polycrystals, 1.3 kg/mm2 for [11\={2}0] and [10\={1}0] crystals, and 1.1 kg/mm2 for [0001] crystals.
    Download PDF (1334K)
  • Jirô Watanabé
    1961 Volume 25 Issue 10 Pages 626-629
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    For zinc single crystals with the [0001],[10\={1}0] and [11\={2}0] orientations, the fatigue strength as determined from the cantilever rotating bending tests has been compared with the static strength determined from the tensile tests. In [0001] crystals, the normal stress acting on the cleavage-fracture plane (0001) at the endurance limit, which is defined conveniently as the fracture stress at 107 cycles, is about a half of the normal fracture stress in the tensile test, but the resolved shear stress operating along the (0001)⟨11\={2}0⟩ direction at the endurance limit coincides with the critical resolved shear stress of the (0001) ⟨11\={2}0⟩ slip system in the tensile deformation. The latter relation also holds for the(0001)⟨11\={2}0⟩ slip, {11\={2}2}⟨\={1}\={1}23⟩ slip or {10\={1}2} twinning in fatigued [10\={1}0] and [11\={2}0] crystals. These findings indicate that the endurance limit, below which the fatigue failure does not occur, in zinc single crystals is determined by the critical resolved shear stress of the active slip or twinning system. It has also been found that the slope of the S-N curve depends on the easiness of plastic deformation of the crystal concerned.
    Download PDF (1011K)
  • Jirô Watanabé
    1961 Volume 25 Issue 10 Pages 629-634
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Surface markings such as slip lines, twin bands, and cracks were observed metallographically on zinc single crystals with [0001],[10\={1}0] and [11\={2}0] orientations and polycrystals, as fatigued by a single-ended cantilever rotating bending machine. [0001] single crystals cleavage-fracture along (0001) planes on which the {10\={1}2} twin bands, river-patterns, and striated patterns were found. A few (0001)[11\={2}0] slip lines were observed on the lateral surface of [0001] single crystals,endorsing their poverty in plasticity and fatigue. [10\={1}0] and [11\={2}0] single crystals show {0001}⟨11\={2}0⟩ and {11\={2}2}⟨\={1}\={1}23⟩ slip lines and {10\={1}2} twins. Their fracture surfaces show stepped structures constructed by the cleavage along {10\={1}0} planes of the matrix and along {0001} planes of the twin. Polycrystals show a transcrystalline fracture in which all the characteristic markings of single crystals appear. The difference of markings in variously stressed crystals could not be detected owing to its fatigue-poor properties. It has been found that no surface marking is observed on single crystals stressed below the endurance limit, which is in harmony with the conclusion obtained in our preceding paper that the endurance limit of a single crystal is determined by the critical resolved shear stress of active slip or twinning system.
    Download PDF (2258K)
  • Kohji Muramatsu
    1961 Volume 25 Issue 10 Pages 635-639
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Various gas extraction techniques have been tested to obtain a suitable one for micro-analyses of hydrogen, oxygen or nitrogen in nickel or iron, by employing a vacuum-fusion gas-extraction apparatus constructed by the author’s plan. In this apparatus, the gas evolution rate from either solid or liquid state is easily observed and the sensitivity of measurement of gas amount is usually 0.5 micron-liter. These tests show that (1) solid diffusion extraction at 850°C gives larger results than that due to either the 1200°C tin-fusion or the 1600°C single-fusion extraction technique, for micro-analysis of hydrogen in both nickel and iron, (2) perfect extraction of nitrogen out of iron samples is so difficult even when the extraction temperature is elevated to 1800°C, that the vacuum-fusion gas extraction at 1800°C for 20 min give 42 ppm of nitrogen while the Kjeldahl method gives 64 ppm for the samples from a same experimental iron ingot.
    Download PDF (1778K)
  • Hiroyasu Mitani, Norihiko Nakanishi
    1961 Volume 25 Issue 10 Pages 639-642
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The authors have been studying on the complicated phase transformations occuring in Cu-Al binary alloys by means of the dilatometric and the electric specific resistance measurements. In this report, the specific-heat measurement was carried out to account for the cause of an alteration in Al concentration which appeared in several heat-treatments, namely, in the case of air-cooling and furnace-cooling from the β phase and in the case of the reversible treatment of the β′ martensite respectively. As a result of the experiments, it was found out that the ordering reaction, Cu3Al, advanced quickly during the above treatments, resulting, in the alteration in Al concentration and Ms point, and the β′ martensite containing the Al concentration close 12.4 wt%, the Cu3Al composition, coming into formation.
    Download PDF (1287K)
  • Kazuteru Senda
    1961 Volume 25 Issue 10 Pages 643-647
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The heat-treatment conditions which exert influences on the hardness and the toughness of high carbon chromium steel quenched, and quenched and tempered at low temperatures, were studied. The toughness were measured by bending test. The heat treatment condition which gives the highest bending strength under definite hardness was found. Of the specimens with the hardness above Rc 62, the specimen of steel having lamellar pearlite structure before hardening gave best results. There are various combination of hardening and tempering temperature to get the expected hardness of specimen, because the hardness after hardening is different according to the quenching temperature. When a hardness below Rc 60 is expected, the lower the quenching temperature the higher the toughness. The bending strength depends exclusively on the hardness of specimen, whatever combination of tempering temperature and holding time may be applied when quenched from 840°C. In this investigation, it was confirmed that there is a brittleness point at the tempering temperature about 180°C.
    Download PDF (1889K)
  • Kazuteru Senda
    1961 Volume 25 Issue 10 Pages 647-651
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    When cooled from austenite region, bainite-transformed Ni-Cr-Mo steel contains a small quantity of stable austenite containing small quantities of martensite and called “bainitic retained austenite”, at room temperature. Through slower cooling process, most of the existing austenite is transformed into pearlite, but in this case also, a very small part of austenite is retained as it is. This is named it “pearlitic retained austenite”, hereunder. Pearlitic retained austenite is not completely transformed in the course of simple slow cooling. In order to find some process of heat treatment by which pearlitic retained austenite will be completely changed, the effect of intermediate holding in the cooling process on pearlite transformation was studied by means of S-curve testing. An X-Y recorder which records the change of sample length by differential transformer was used to trace S-curves. The effect of time of holding intermediately at the temperature just below the A1 transformation point is not simple. The stability of austenite does not always decrease according to the length of the holding time just below A1 temperature. When the intermediate holding temperature is lower, austenite becomes unstable relatively. But even in this case, the stability increases locally, if the austenite transforms to bainite partially during intermediate holding time. In short, in the austenite to pearlite transformation, there is a phenomenon which is analogous to stabilization of the austenite-martensite transformation. And it was shown that the effect of incubation period at a temperature of pearlite transformation does not proportionaly contribute to pearlite transformation at other temperature, but in some cases the austenite is rather stabilized.
    Download PDF (1663K)
  • Shizuya Maekawa, Yoshio Yoneyama
    1961 Volume 25 Issue 10 Pages 651-654
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    A polarographic method has been studied as a way to determine 0.05 to 4%Al contained in ferrovanadium, ferrozirconium and ferrotitanium. According to this method, such elements as Fe,Ti,Zr,V are extracted wholly in the form of cupferrate using benzene ether mixture solution. The organic substances in the aqueous layer are decomposed with nitric and perchloric acids. Afterwards, Al is determined by the polarographic method invented by Willard and Dean(6). It is to be noted that, in the case of a sample like B.S.S. No. 61 ferrovanadium, however, we have to eliminate Ni and Cr previously by means of mercury cathode electrolysis, as it contains a big amount of those elements.
    Download PDF (856K)
  • Nobuo Shiota, Yutaka Aizawa
    1961 Volume 25 Issue 10 Pages 654-658
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The on-the-spot method of analysis reported in this paper is the thermal conductivity method using the semi-conductor thermister gas analyser, which enablesus to determine the amount of gas evolved at the time of setting of the molten aluminium metal within ten minutes. The summary of the results obtained is as follows. (1) With regard to the type of alloys, the amount of gas evolved increases in the order of 17S, 2S, 75S, and 56S, and further, the amount of gas evolved will be influenced by the proportion of scraps used. (2) The above-mentioned method for analysis is more effective in the analysis of gas in alloys than in the analysis of gas in 1S or 2S. (3) The reaction of pure aluminium with steam is very rapid, and hydrogen gas is absorbed during melting.
    Download PDF (1602K)
  • Koichi Sugimoto, Masao Ibaraki
    1961 Volume 25 Issue 10 Pages 659-662
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The room-temperature internal friction in an electrolytic iron, a magnetic soft iron and several commercial low-carbon steels, which were extended by 1∼10%, was measured by the transverse vibration method as described in the previous paper. According to the results obtained immediately after the cold-working, the amplitude-independent internal friction was increased and the amplitude-dependent internal friction was decreased by cold-working as compared to those of the annealed specimens. When the cold-worked specimens were kept at room-temperature, the amplitude-independent internal friction was reduced to a value that was nearly equal to the background damping in the annealed specimens, and the amplitude-dependent internal friction was decreased by a very small but clearly observable amount. The higher the degree of extension was, the more marked were the changes observed in both parts of the internal friction. The principal cause of the amplitude-independent internal friction in cold-worked iron and steel can be considered as representing the loss produced by the reversible movement of dislocation segments which are free from pinning by solute atoms. The reduction in the amplitude-independent and the amplitude-dependent parts during room-temperature aging may be explained by the interaction between the solute atoms and the dislocations, although the reduction of the latter can be observed only for the first few hours in the recovery curve.Some remaining internal friction was observed in specimens that were completely recovered, and the amplitude-independent part seemed to be mostly the tail of the Snoek peak, while the amplitude-dependent part seemed to be the loss due to the magneto-mechanical hysteresis.
    Download PDF (1683K)
  • Shoichi Katoh
    1961 Volume 25 Issue 10 Pages 663-667
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    In a previous report, the author introduced that the modified iron-base heat-resisting alloys of precipitation type were comparable to Nimonic 80A in creep-rupture properties. In this investigation, the author studied the high temperature properties of modified alloys containing a small amount of Mo,W,V,Nb,Ti,Al and B in iron-base Cr 16%, Ni20% and Co 20% alloys. 16 mmφ forged bars were used for solution annealing, age hardening, short-time tensile tests, high temperature creep-rupture tests, electron-microscopic and X-ray diffraction tests. Specimens containing Ti+Al have remarkable age-hardenable characteristics and short-time high-temperature tensile strength. The creep-rupture properties of alloys having the highest strength in these modified alloys, investigated up to 732°C, were better than those of commercial alloys such as Nimonic 90, Inconel X or Nimonic 95 and were comparable to those of Nimonic 100 or M-252. By the X-ray diffraction data on the electrolytic extracts from these specimens after creep-rupture tests, MC, M23C6, σ phase, Laves phase, γ′ phase, β phase and boride have been identified. There control alloys precipitated Laves phase by adding Nb and β phase by increasing Al content in Ti+Al. The author found that the deterioration of high temperature characteristics of these control alloys have relation to precipitations of massive β and L phase. It might be suggested that the remarkable age-hardening and the high rupture strength properties of these alloys are principally caused by precipitation of aluminum-poor γ′ type Ni3(AlTi).
    Download PDF (1672K)
  • Shigeru Morita
    1961 Volume 25 Issue 10 Pages 667-670
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The effect of cold-working on the stress corrosion crack sensitivity in boiling NaCl with or without additional oxidizing agent was studied in 18-8 and 18-12 Mo steel. The transgranular corrosion cracking appeared in the specimen immersed in NaCl solutions provided that the solution had suitable composition for cracking. Comparing 18-8 with 18-12 Mo in its crack susceptibility, it has been shown that in most of these solution, the latter containing Mo was more resistant to the corrosion cracking than the other, and that the result did not coincide with that in MgCl2 solution. In this experiment, the preferential attack of locally transformed ferrite phase was not so predominent as in MgCl2. As mentioned above, the condition of corrosion environment which is apt to cause cracking in stainless steel depends on steel, as was shown in the case of pitting corrosion. In addition, the mechanism of crack initiation was discussed.
    Download PDF (1591K)
  • Shigeru Morita
    1961 Volume 25 Issue 10 Pages 671-675
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The effect of sensitizing heat treatment on the susceptibility for cracking and crack propagation in six austenitic stainless steels was studied using U-bend specimens. It has been considered that in general the stress corrosion cracks of austenitic stainless steel in chloride solution are of transcrystalline nature. However, some results of this study showed intergranular cracks in sensitized steel. From the results of 42%MgCl2-experiment, cracks were always transcrystalline in the sensitized specimen as well as in the annealed one, and the crack sensitivity of the steels did not increase by sensitizing treatment. On the contrary, intergranular cracks appeared in some of the sensitized specimen in NaCl solution. In this case, steels were more sensitive to the stress corrosion cracking in sensitized state than in annealed state.In extra-low carbon or stabilized steels, however, the cracks were always transcrystalline regardless of the pre-treatment of the specimen, and the crack sensitivity of these steels did not increase by sensitizing treatment. The current density-potential curves in chloride solution were observed on these steels, and the relationship between the anodic polarizability of steels and the susceptibilit and the path of stress corrosion was discussed. The conditions causing intergranular cracking were also discussed.
    Download PDF (1735K)
  • Shigeru Morita
    1961 Volume 25 Issue 10 Pages 675-679
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The effect of heat-treatment temperature on the susceptibility of stress corrosion cracking was studied using a direct load apparatus. The quantitative relationship between applied stress and the time to failure was obtained on annealed 18-8 in boiling 42%MgCl2 solution. Between 400∼800°C, the effect of heating temperature on the susceptibility of stress corrosion was studied in boiling 42%MgCl2 and NaCl solution. In MgCl2 solution, the effect of heating temperature was very small and the crack occurring in this solution was always transgranular. In NaCl solution, on the contrary, the susceptibility was definitely increased by heating at 600 to 800°C, and in this temperature range, the path of cracks was mainly intergranular. In NaCl solution, intergranular corrosion was scarcely observed on the surface of sensitized unloaded specimen though the specimen under tensile stress failed by intergranular cracking. In acidified copper sulphate solution, which has been known to attack sensitized specimens intergranularly without any tensile stress, the propagation of intergranular crack in the stressed specimen was much more serious than the penetration of ordinary intergranular corrosion through the surface the specimen. The conditions causing intergranular cracking were discussed again.
    Download PDF (1758K)
  • Susumu Morioka, Minoru Takahashi, Yoshinobu Sawada, Saburo Shimodaira, ...
    1961 Volume 25 Issue 10 Pages 679-683
    Published: 1961
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The electroplating condition of permalloy films formed on copper plates has been studied in relation to the composition of the films. This composition depends not only on the bath composition but also on current density, pH and temperature. 80%Ni-Permalloy film can always be obtained under the following plating condition: Bath composition, 32 g/L of NiSO4·7H2O, 20 g/L of NiCl2·6H2O, 18 g/L of FeSO4·7H2O and 30 g/L of H3BO3; current density, 1 A/dm2; pH, 2.8 to 3.0; temperature, 58∼60°C. Magnetic hysteresis loops have been measured by a 50 cps B-H loop tracer in 80%Ni-permalloy films. The polishing direction of substrates has been found to affect very much the shape of B-H curves. The rectangular B-H loops correspond to the direction parallel to scratches due to polishing. The coercive force, Hc, is proportional to D−\frac65 in the films thinner than 5000 Å, D being the film thickness. In the films thicker than 5000 Å, however, Hc becomes a constant value, 2.8 Oe, which is far larger than the value of the corresponding bulk alloy.
    Download PDF (1547K)
feedback
Top