All issues
Volume 31, Issue 10
Displaying 1-20 of 20 articles from this issue
- |<
- <
- 1
- >
- >|
-
Akiyoshi Miyoshi, Akio Hara, Yoshinobu Sugimoto1967 Volume 31 Issue 10 Pages 1123-1126
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffects of lapping on the crack length around the Vickers indentation were examined in various cemented carbides. And then, to analyze the lapping effect, the dependence of micro-hardness on lapping time was studied with the same specimens and WC single crystals.
The results are summarized as follows:
(1) A remarkable dependence of the crack length on lapping time was obserbed in ordinary cemented carbides having the WC phase. On the contrary, no dependence was obserbed in (W, Ti, Ta)C-Co alloys with no WC phase.
(2) As for the micro-hardness, the same tendency as the crack length was obserbed. As for WC single crystals, a considerable dependence of micro-hardness on lapping time was obserbed on the basal plane.
(3) By measuring the micro- and macro-hardness of cemented carbides under various test loads, it was shown that the depth of several microns of the surface was hardened by lapping.
(4) From the results obtained, the dependence of the crack length on lapping time may be explained by the work hardening of the WC phase during lapping.View full abstractDownload PDF (1822K) -
Tamotsu Fukatsu, Kazuhiko Yuhara, Keiichi Kobori1967 Volume 31 Issue 10 Pages 1127-1132
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe wear resistance of cemented carbide is usually estimated from the hardness, but it is often inadequate to interpret the practical problems only from the hardness. The present study dealt with the relations between the wear resistance and the properties of WC-Co sintered alloys which were prepared by varying the cobalt content, particle size of WC powder, small addition of TaC and sintering temperature.
The wear resistance was measured from the flank wear land produced by the turning of cement-mortar, gray cast iron and carbon steel. Generally, as mentioned previously, the wear resistance increased with increasing hardness and coercive force or decreasing cobalt content and WC grain size of the alloys. The wear resistance increased linearly with decreasing WC grain size of the alloys in spite of the particle size of the WC powder used as raw material. However, the relations between hardness or coercive force and wear resistance were affected by the particle size of the WC powder; that is, both hardness and coercive force were the same, but the wear resistance of the alloys made of coarse WC powder was better than that of fine WC powder. Such a difference in wear resistance by the particle size of the WC powder was more remarkable in the turning of gray cast iron than that of cement-mortar. The effect of a small addition of TaC was observed in the turning of steel, but not in the turning of the cement-mortar or gray cast iron, and the effect of the grain size of the WC powder of the alloys was predominant in the latter.View full abstractDownload PDF (1950K) -
Hisasuke Takeuchi, Toyoji Kobayashi1967 Volume 31 Issue 10 Pages 1133-1139
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSContact materials used in oil-filled tap changers for regulating the voltage of transformers or electric locomotives must be wear resistant, because the accumulation of particles produced from the wear of sliding contacts tends to cause a high voltage breakdown. The purpose of this investigation was to find out the most desirable pair of electro-conductive materials, which would make the oil-lubricated current collector maintenance-free for a long period of time.
A series of wear tests were carried out with fourteen different materials contacted with a copper plate, using (a) a horizontal sliding type wear tester without current flowing, and (b) an actual high voltage tap changer for the electric locomotive with current flowing through the contacts.
Materials tested were Cu-Fe cast alloys, Ag-W and Cu-W sintered alloys, aluminium bronze, manganese bronze, etc. The results are summarized as follows:
(1) By measuring the weight loss and roughness of the worn surfaces, the group of Cu-Fe alloys, especially the one containing 40%Cu, were found to have excellent wear resistant properties, followed by Ag-W and Cu-W alloys.
(2) The wear resistance of the Cu-Fe alloys was improved by heat treatments; by quenching and tempering, a hard contact material with relatively high conductivity was obtained. The microstructure of Cu-Fe alloys consisted of two phases, hard iron-rich phase and soft copper-rich one. The difference of micro-hardness between the two phases was enhanced by heat treatments. This was considered to account for the superior wear resistance of the alloys, particularly when heat-treated.
When Cu-Fe alloys were contacted with Cr-Cu alloys, the total weight loss was much less than that when contacted with pure copper.View full abstractDownload PDF (2822K) -
Tunezo Saito, Yutaka Sakuma1967 Volume 31 Issue 10 Pages 1140-1144
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA levitation melting technique was used to obtain the densities of liquid iron, cobalt and nickel between their melting points and 2200°C. The results are as follows:
(1) The densities of liquid iron, cobalt and nickel are given by the following formulas:
(This article is not displayable. Please see full text pdf.)
(2) The quotient of the entropy of fusion and the volume change on fusion (δm≡ΔSm⁄ΔVm) is nearly constant (53∼55 cal/deg). This value agrees with that of the previous data obtained on several metals.
(3) An estimate of critical temperature Tc and critical density Dc of these metals was made by using well established laws (the principle of corresponding state and the law of Cailletet-Mathias etc.) and a tentative liquid range diagram of iron, cobalt and nickel was constructed on the analogy of mercury.View full abstractDownload PDF (1512K) -
Hiroyasu Funakubo1967 Volume 31 Issue 10 Pages 1144-1148
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSL’essai de frottement intérieur sous champ magnétique de 150 Oe sur les éprouvettes monocristallins du fer pur de différente pureté nous a montré les remarques présentés comme les suivants;
(i) La variation des valeurs de frottement intérieur de l’éprouvette de {100}[100] a la même tendence que celle effectuée sans champ magnétique. Mais, quand l’orientation s’écarte de plus en plus que celle de {100}[100], l’effet de champ magnétique augmente.
(ii) La valeur de la contrainte critique produite par le phénomène reversible-irreversible de la valeur de frottement intérieur est si importante sur l’éprouvette de {100}[100] (plus de 330 g/mm2). Mais, elle se diminue quand l’orientation s’écarte progressivement de {100}[100].
(iii) Dans la condition limitée de cet essai, la variation de frottement intérieur en fonction de la contrainte posée sous champ magnétique sera causée principalement par le glissement.View full abstractDownload PDF (1544K) -
Shigeo Oya, Eiichi Kato, Hideya Shimizu, Takayasu Takada1967 Volume 31 Issue 10 Pages 1149-1153
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe specimens for hydrogen determination were taken from molten copper and copper-tin alloys with a copper die sampler (modified Tayler’s sampler) and were immediately water-quenched. The procedures for hydrogen determination included hot extraction, separation of hydrogen from other gases through a palladium tube and reading a McLeod gage.
At room temperature, approximately 5 and 3% of hydrogen is evolved, respectively, from copper and the copper-tin (89:11) alloy 24 hr after sampling. In the present experiment, the extraction has successfully been made at the temperatures from 800° to 900°C. It takes less than one hour for extracting, although the extracting time depends on the size, shape and hydrogen content of the specimen. These procedures lead to the hydrogen content in pure copper from 3.93 to 7.34 ppm and the standard deviation 0.36 ppm, and the hydrogen content in the copper tin (89:11) alloy from 1.76 to 5.03 ppm and the standard deviation 0.22 ppm. In the present operation, considerable agreement is found in the case of copper between the determined values and the hydrogen solubility data, but there are appreciable differences in the case of the copper-tin alloy.View full abstractDownload PDF (1698K) -
Eiichi Kato, Harunobu Ueno1967 Volume 31 Issue 10 Pages 1154-1157
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe tin-fusion technique was applied for the determination of hydrogen in molten pure copper and molten copper-tin alloy. Pure copper and copper-11.5% tin alloy were melted in a graphite crucible in the atmosphere of hydrogen at a pressure of 1 atm. Specimens were taken from the melt with a copper die sampler and then water-quenched. The hydrogen in the samples was extracted by the tin-fusion technique at 750°C, seperated from other gases with a palladium tube and measured with a McLeod gauge. In order to examine the accuracy of this technique, the determined values were compared with the values of hydrogen solubility in these molten metal and alloy. The results obtained are as follows: (1) Dioxidizing agents were needed in the tin bath and C, Mn, Ge, V, Si, Ge and Mn, and Misch metal were used as dioxidizing agents. Among these agents Ge and Ge-Mn were proved to be good dioxidizing agents and gave a highly accurate hydrogen content and a low blank. (2) The hydrogen in each specimen was extracted within 20 minutes. (3) In the case of pure copper, the coefficients of variations at various melting temperatures were 0.005 at 1150°C, 0.012 at 1200°C and 0.013 at 1250°C, while in the case of copper-11.5% tin alloy, these coefficients were 0.002 at 1150°C, 0.008 at 1200°C and 0.018 at 1250°C.View full abstractDownload PDF (1377K) -
Akira Yazawa1967 Volume 31 Issue 10 Pages 1158-1163
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to clarify the basic principles of metallurgical processes for sulfide ores, the systems including iron, sulfur and oxygen were investigated thermodynamically, and the changes in the equilibrium aspects brought about by the coexistence of the fourth constituent or the variation in temperature were discussed. Based upon the available thermodynamic data, equilibrium relations among the participating constituents were first derived, and the results are illustrated in the isothermal reaction diagrams in which basic thermodynamic quantities are taken for both axes. In the hydrometallurgical process, behaviors of iron sulfides are illustrated by the pH-potential diagrams, and the selective leaching processes are explained. Next, the equilibrium relations in iron-sulfur-oxygen system at the roasting temperature are illustrated in the isothermal diagrams in which logPS2 and logPO2 are both axes. The selective sulfatization roasting in practice could be explained successfully. Isothermal reaction diagrams for this ternary system were also constructed at the smelting temperature, which explained the behaviors of iron oxides in matte smelting. Furthermore, desulfurization of molten iron was discussed based upon a similar diagram.View full abstractDownload PDF (2486K) -
Reiichi Ohno, Tsuneo Ishida1967 Volume 31 Issue 10 Pages 1164-1169
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe vacuum melting of Fe-Mn, Fe-Cu, Fe-Sn, Fe-Cr, Fe-S and Fe-Si-S alloys was carried out at 1600°C, by using a high frequency induction furnace and the rate of evaporation of alloying elements was studied. Evaporation of all the alloying elements follows first-order kinetics, and specific evaporation constant KS of each alloying element was obtained. Evaporation coefficient α of each alloying element was obtained both experimentally and theoretically according to the equation of Olette. It was reconfirmed that the experimental value agrees with the theoretical one which was obtained by introducing CS⁄Cm into the equation of Olette in Fe-Mn and Fe-Cu alloys. Furthermore, a linear relation was found to exsist between α and KS. Following Ward, CS⁄Cm and the rate constants for evaporation and for transport in the melt were calculated.
In the Fe-S alloy, the condensation coefficient of sulfur was obtained by applying the equation of Machlin under the assumption that the velocity of streamline flow is constant irrespective of the kind of alloys.View full abstractDownload PDF (1832K) -
Isao Gokyu, Junji Kihara1967 Volume 31 Issue 10 Pages 1170-1176
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe work-hardening behaviours at 283°K of 99.99%, 99.9% and 99.3% aluminium polycrystalline specimens are analyzed from the temperature and strain-rate dependences of flow stress of the specimens prestrained at 283°K.
The main results obtained are as follows:
(1) The work-hardening behaviors depend largely on the purity of the specimen.
(2) The thermal part of the flow stress, σt, is determined by the intersection mechanism when σt is high, while the flow-mechanism is not a single activated process when σt is low.
(3) The athermal part of the flow stress, σa, is proportional to the σt when the activation process is the intersection mechanism and the activation energy of deformation is 0.2 eV. This is valid for all the specimens.
(4) The purity affects the work hardening through the dislocation accumulation during deformation.
(5) σa can be related to the dislocation density N by the equation, σa=2×0.4μb\sqrtN, where μ is the shear modulus and b is the strength of Burgers’ vector.View full abstractDownload PDF (1959K) -
Isao Gokyu, Junji Kihara, Teruo Kishi1967 Volume 31 Issue 10 Pages 1176-1180
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA number of investigations have been performed on the strengthening mechanism of ausformed martensite, and the following mechanisms have been proposed:
(1) Direct transfer of work-hardening structure from austenite to martensite.
(2) Dispersion hardening due to micro carbide precipitation.
(3) Decrease of martensite-plate size.
(4) Decrease of residual austenite.
(5) Production of twined martensite.
In this investigation, 4340-steel is ausformed in the metastable austenite-temperature range at high strain rates (102∼103/sec) by a counterblow forging tester, and the flow stress of the ausformed austenite at the working condition and the hardness of the ausformed martensite are measured. The following relation is obtained:
M_H = M_H^0 + 3A σ, where MH is Vickers’ hardness of the ausformed martensite, Aσ is the flow stress of the ausformed austenite at the ausforming condition and MH0 depends on both the chemical compositions and the prethermo-mechanical history of specimens. The factor, 3, of Aσ represents that the work hardening is directly transferred from austenite to martensite. On the basis of detailed discussions, it is concluded that the strengthening mechanism of the ausformed martensite is a direct transfer of work hardening and the other mechanisms mentioned above have a secondary effects. Especially, the hardening due to micro-carbide precipitation does not contribute essentially to the ausform-strengthening of martensite.View full abstractDownload PDF (1174K) -
Michitomo Kato1967 Volume 31 Issue 10 Pages 1180-1185
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn einem früheren Bericht über die Korngrenzengleitung von reinem Aluminium mit Kupferzusätzen zwischen 0.2% unt 0.5% wurde für die Al-0.2%Cu Legierung eine starke Behinderung der Korngrenzengleitung berichtet.
In der vorliegenden Arbeit wurde der Einfluss verschiedener physikalischer Eigenschaften von gelösten Elementen auf die Korngrenzengleitung und denen Aktivierungsenergie untersucht. Hierzu wurden Scherversuche an Bi-kristallen aus Aluminium mit 0.2%Cu, Ag, Mg order Zn bei konstanter Temperatur durchgeführt. Die Versuchsergebnisse können wie folgt zusammengefasst werden:
(1) Die Korngrenzengleitung ist bei einer Zugabe von Mg am geringsten und nimmt in der Reihenfolge Ag, Zn, Cu zu. Dies weist darauf hin, dass die Korngrenzengleitung nicht nur vom Schmelzpunkt und der Löslichkeit sondern vor allem von dem Atomradius des gelösten Elementes abhängt. Hierbei ergibt sich, dass mit zunehmenden Atomradius die Korngrenzengleitung stärker behindert wird.
(2) Die Abhängigkeit der Korngrenzengleitung von der Zeit zeigt für die einzelnen gelösten Elemente nur geringe Unterschied; lediglich bei einem Zusatz von Mg erfolgt eine starke Beeinflussung. Insbesondere bewirkt bei konstantem Zeitintervall das Magnesium auch eine weit grössere Temperaturabhängigkeit als die anderen Elemente.
(3) Die Analyse mittels einer Mikrosonde konnte keine Seigerung in den Proben nachweisen. Es war daher unmöglich, die Wirkung löslicher Atome an den Korngrenzen auf die Korngrenzengleitung klar festzustellen.
(4) Die Aktivierungsenergien für die Korngrenzengleitung wurden an jeder Probe aus dem Zusammenhang zwischen den anfänglichen Gleitgeschwindigkeiten und den Temperaturen berechnet. Hierbei ergaben sich folgende Werte: Al 10700, Al-Cu 19600, Al-Zn 21700, Al-Ag 24400, Al-Mg 28000 cal/mol.View full abstractDownload PDF (1801K) -
Tomomi Mizuno, Tetsuo Matsumura, Naomi Kotani, Takeshi Goto1967 Volume 31 Issue 10 Pages 1186-1190
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe application of X-ray fluorescence spectroscopy to the analysis of electroslag was undertaken to provide a rapid and accurate method for the determination of CaO, T.Fe, MnO, TiO2, SiO2, MgO and Al2O3.
Powdered slag sample with Na2B4O7 flux was fused in the Pt crucible and poured the melt into a graphite mold to form a glass bead which had a very clean and flat surface. Analysis was carried out by irradiating X-ray beam directly on the surface of a glass bead. The precision of the method was 0.1∼4.5% in coefficient of variation. The accuracy of the final results was as good as that obtained by chemical methods. Between ten and fifteen samples per day can be analyzed.
Easiness of synsethesing the standard sample, reduction of the effect of the other element, etc. are some advantages of this method, which enable the method to be applicable to many other powdered samples, such as many kinds of slags, ores and oxides.View full abstractDownload PDF (1940K) -
Akira Isaka1967 Volume 31 Issue 10 Pages 1191-1195
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe residual part and the eddy current part were separated from the total losses of MnZn ferrites to make clear their magnetic loss behaviour for high frequency. The chemical composition and temperature dependence of magnetic loss were investigated. The activation energy derived from magnetic loss measurements was compared with the activation energy of the D.C. resistivity. The results obtained were as follows: The iron-excess ferrites show the electron diffusion loss due to Fe2+\ ightleftarrowsFe3+. The lose maximum exists at low temperatures so that the residual loss is very small at room temperature, although the eddy current loss increases because of the low resistivity. For the iron-deficient ferrites, the electron diffusion loss due to Mn3+\ ightleftarrowsMn2+ is observed. Since the maximum of loss shifts to the high temperature range, the residual loss increases at room temperature. In this case, the increase of resistivity results in the decrease of eddy current loss. This experiments shows that the magnetic behaviours of electron diffusion are independent of ZnO content.View full abstractDownload PDF (1862K) -
Ryôfu Miyasawa1967 Volume 31 Issue 10 Pages 1196-1201
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe longitudinal magnetostriction of the [100] rod single crystals of iron containing 0.5%Al has been studied at ordinary temperatures, using the optical lever method, in the thermally demagnetized state and in the alternating-current demagnetized state. It has been found that the dependence of the magnetostrictive behaviors of these specimens on the method of demagnetization is more distinguished than that of the [100] single crystals of pure iron reported until now. Also, it has been determined quantitatively, from the magnetostriction vs. magnetization curves in the thermally demagnetized state, that the volume fraction of domains with magnetization vectors along the direction of easy magnetization nearest to the rod axis in the unmagnetized state ranges from 0.11 to 0.15, and that the value of the magnetostrictive constant, λ100, is 15.7×106. Furthermore, the deviation of the domain distribution in the state of remanent magnetization from that governed by Kaya’s rule has been evaluated.View full abstractDownload PDF (2275K) -
Ryôfu Miyasawa1967 Volume 31 Issue 10 Pages 1202-1207
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe longitudinal magnetostriction of the [110] rod single crystals of iron containing 0.5%Al has been studied at ordinary temperatures, using the optical lever method, in the thermally demagnetized state and in the alternating-current demagnetized state. It has been found that the magnetostrictive behaviors of these specimens depend markedly on the method of demagnetization, and, from the magnetostriction vs. magnetization curves in the thermally demagnetized state, the volume fraction of domains with magnetization vectors along the direction of easy magnetization nearest to the rod axis in unmagnetized state ranges from 0.19 to 0.23; furthermore, the deviation of the domain distribution in the state of remanent magnetization from that governed by Kaya’s rule has been evaluated. Moreover, the fact that the magnetostriction vs. magnetic field curves in the magnetization range of rotation are linear, irrespective of the method of demagnetization, can be explained by the experimental fact that the square of the magnetization is approximately proportional to the magnetic field, but to the magnetostriction as well, from which an attempt has been made for the determination of the magnetostrictive constant, λ111.View full abstractDownload PDF (1263K) -
Ryôfu Miyasawa1967 Volume 31 Issue 10 Pages 1208-1213
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe longitudinal magnetostriction of the [111] rod single crystals of iron containing 0.5%Al has been studied at ordinary temperatures, using the optical lever method, in the thermally demagnetized state and in the alternating-current demagnetized state. It has been found that the dependence of the magnetostrictive behaviors of these specimens on the method of demagnetization is not so conspicuous as in the [100] and [110] specimens, although it is affected distinctly in the magnetization range of domain wall displacement. From the magnetostriction vs. magnetization curves in the thermally demagnetized state, the deviation of the domain distribution in the state of remanent magnetization from that governed by Kaya’s rule has been evaluated. Furthermore, it has been noted that, as for the increase of the value of magnetostriction between the state of remanent magnetization and that of magnetic saturation, the relation deduced from Kaya’s rule holds practically, unlike the [100] and [110] specimens. Moreover, the fact that the magnetostriction vs. magnetic field curves in the magnetization range of rotation are linear, irrespective of the method of demagnetization, can be explained in a way similar to that of the [110] specimen.View full abstractDownload PDF (1254K) -
Tatsuo Maekawa, Masaru Kagawa, Nobuo Nakajima1967 Volume 31 Issue 10 Pages 1213-1219
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe corrosion behaviors of AISI 304 and 304 L stainless steels were studied to clarify the effects of temperature, surface finish and dissolved oxygen in high-temperature water and superheated steam. In degassed water, the steels indicated a maximum corrosion rate between 250° and 350°C, and the corrosion rate was affected largely by the surface finish. In aerated water, the corrosion rate was not so much affected by the corrosion temperature and surface finish. In superheated steam, the corrosion rate increased with increasing temperature and was affected markedly by the surface finish at high temperatures. The corrosion films produced in degassed water and in steam consisted of magnetite and chromite, and the chromite content increased with increasing temperature, whereas those produced in aerated water consisted of γ Fe2O3. The α phase transformed from the γ phase by cold-working or surface abrading decreased the corrosion resistance in degassed water, but it greatly increased the corrosion resistance in superheated steam.View full abstractDownload PDF (1211K) -
Kôichi Aoki, Hiroshi Mimura, Yoshio Oozeki1967 Volume 31 Issue 10 Pages 1220-1221
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (131K) -
1967 Volume 31 Issue 10 Pages 1221
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPlease see pdf. Wrong:C. H. G. Krafft and Anacker, H. J. Enjell and A. Bäumel, (a) Impedance change vs time for stress corrosion cracking in NH3 vapour Right:C. H. G. Krafft and Amacker, H. J. Engell and A. Bäumel, (a) Impedance change vs time for stress corrosion cracking a solid line: NH3 vapour a dotted line: Mattsson's solu.View full abstractDownload PDF (17K)
- |<
- <
- 1
- >
- >|