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Volume 32, Issue 12
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Ôhiko Kammori, Isamu Taguchi, Ken-ichi Suzuki, Akihiro Ono1968 Volume 32 Issue 12 Pages 1185-1189
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe hydrochloric acid extraction method at room temperature, the potentiostatic electrolysis method with 5%Na-citrate-1.2%KBr electrolyte (pH 5) and the potentiostatic electrolysis method with 7%HCl-3%FeCl3-ethyleneglycol electrolyte, which was previously reported by the present authors as a method for the quantitative extraction of vanadium carbide (V4C3), were compared for the quantitative extraction of 0.01∼0.25% of titanium carbide (TiC) from Fe-Ti-C steel. The highest values were attained by the 7%HCl-3%FeCl3-ethyleneglycol-electrolyte potentiostatic electrolysis method.
About 0.5 g of steel sample is potentiostatically electrolyzed at −280 mV vs SCE in about 400 mL of 7%HCl-3%FeCl3-ethylenglycol. Extracted residues are collected through Cella filter and washed by ethyl alcohol. Titanium in the residues is determined by Chromotropic acid spectrophotometry and titanium carbide (TiC) is calculated.
By this procedure, titanium carbide was quantitatively extracted and determined with good reproducibility. The time for the extraction ranged from 5 to 10 hr and the time for the titanium determination about 30 min.View full abstractDownload PDF (1719K) -
Ôhiko Kammori, Naoharu Yamaguchi, Ryoichi Suzuki1968 Volume 32 Issue 12 Pages 1190-1192
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the determination of small amounts of oxygen in iron and steel, the formation of oxide film and the adhesion of oxide on the surface in sample preparation may make the significant errors in the analytical results. So the effects of various polishing methods, such as abrasions with emery paper and silicon carbide paper, buffing with alumina paste (1 μφ), roughing with lathe, filing, chemical polishing (phosphoric acid+hydrogen peroxide) and electropolishing (glacial acetic acid+perchloric acid), on the determination of oxygen in various kinds of iron and steel were investigated.
As a result of experiments, the specimens prepared by electropolishing gave the most correct and reproducible oxygen value, and it seemed that the electropolishing was most suitable for preparation of specimens containing small amounts of oxygen. In this case, the effects of selective dissolution of metal and oxides was not observed.
The specimens prepared by filing and abrasion with silicon carbide paper gave oxygen values a few ppm higher than the electropolished specimens, so that these methods may not be used for the low oxygen samples, but the samples containing more than 50 ppm may be used in routine analysis. In view of the fact that the abrasion with emery paper gave extraordinarily high oxygen values, it may not be used even in routine analysis.View full abstractDownload PDF (1321K) -
Kaizo Monma, Ryohei Maruta, Toshiro Yamamoto, Yoshihiro Wakikado1968 Volume 32 Issue 12 Pages 1193-1198
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this work, the specimens containing various amounts of carbon and chromium were quenched avoiding the precipitation of undissolved carbides and then the fatigue life and other properties were tested.
The results may be sumarized as follows:
(1) The most suitable carbon content in martensite matrix to obtain the long fatigue life and high mechanical properties is about 0.40 to 0.50%.
(2) The fatigue life, compressive breaking strength and tensile strength show the highest values, when the specimens hardened without undissolved carbides and tempered at low temperatures have hardnesses in a range of 50 to 57 in HRC.
(3) Under the above condition, the fatigue life and the compressive breaking strength depend mainly on the carbon content in martensite matrix, and chromium has litte effect on them.
(4) The presence of chromium as a chemical component of bearing steel is effective to produce homogeneous and fine particle carbides,and facilitates the control of quenching work and increases its hardenability.View full abstractDownload PDF (1699K) -
Kaizo Monma, Ryohei Maruta, Toshiro Yamamoto, Yoshihiro Wakikado1968 Volume 32 Issue 12 Pages 1198-1204
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of carbide particle sizes and amounts of undissolved carbides in martensite matrix on the fatigue life and other properties have been investigated by using the SUJ 2 kind (JIS) of bearing steel having coarse particle carbides and fine particle ones, respectively, and low chromium steels with different carbon contents.
The specimens were previously quenched from various austenitizing temperatures in order that the carbon content in the martensite matrix was made constant, and accordingly the amounts of undissolved carbide in the low chromium steels were changed variously.
The results obtained are summarized as follows:
(1) The bearing steel with fine particle carbides are superior in fatigue life, hardness and compressive breaking strength to that with coarse partile carbides.
(2) In the neighbourhood of the fatigue flaking surface caused by the fatigue life test, cracks do not take place in carbides themselves but proceed along the boundary between carbide and matrix.
(3) When the carbon content in the martensite matrix is constant, the hardness rises slightly with the increase in undissolved carbides, but the fatigue life shortens and the compressive breaking strength decreases.
(4) The presence of some amount of the undissolved carbide is desirable in view of the wear resistance and the control of heat treatment.View full abstractDownload PDF (2318K) -
Sukeaki Kabayama, Eiji Kamijo1968 Volume 32 Issue 12 Pages 1204-1210
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe solid solution of silver containing 5∼20 wt% cadmium were internally oxidized at temperatures between 600°C and 800°C under various oxygen partial pressures. The depth of the subscale formed and the microstracture were investigated with an optical microscope, and the distribution of alloy elements was determined with E.P.M.A. The results were summarized as follows:
(1) The depth of the subscale formed was proportional to the fouth root of the surface oxygen partial pressure.
(2) The activation energy for diffusion of oxygen through the internally oxidized layer was calculated by Wagner’s equation, yielding about 20 kcal/mol.
(3) The size of precipitated CdO particles was considered by the nucleation and growth model, and explained by the feed velocity ratio of the oxygen to solute cadmium at the oxidation front.
(4) The cadmium depleted zone was observed in the center of the fully oxidized strip, especially when the diffusion rate of oxygen was small as compared with the diffusion rate of solute cadmium. The width of the depleted zone was proportional to the thickness of the specimen, the concentration of the solute cadmium and the second root of the diffusion ratio of the solute cadmium to oxygen, while it was in inverse proportion to the fouth root of oxygen partial pressure.View full abstractDownload PDF (1503K) -
Yasuo Fujinaga, Sigemaro Nagakura, Shiguéo Oketani1968 Volume 32 Issue 12 Pages 1210-1216
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTen kinds of Al-Cu alloy (0∼23.8 at%Cu) were rapidly quenched from liquid state by means of a rotating cylinder technique and the structures were investigated with X-ray and electron diffraction as well as electron microscope. Lattice parameter measurements showed that an enforced solid solution was formed beyond the solubility limit of copper in aluminum. In 18.4 at%Cu alloy the solubility was 5 at% in a thick part of the specimen and 16 at% in a thin part subjected to more rapid cooling. Electron microscopic observations suggested that an enforced solid solution with higher copper concentration may be produced in the higher copper alloys, if the cooling rate is made faster. The precipitation from the enforced solid solution was found to take place in the sequence GP→θ″→θ′→θ as in the case of precipitation from the ordinary supersaturated solid solution and that the precipitation temperature becomes lower with increasing copper content. The mechanism of precipitation seems to be essentially the same in both cases.View full abstractDownload PDF (2674K) -
Katsusuke Nagahama, Ken-ichi Hirano1968 Volume 32 Issue 12 Pages 1216-1221
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPrecipitation in Ag-rich Ag-Al alloys was studied by means of hardness, electrical resistivity and X-ray diffraction measurements and optical microscopy. The results are summarized as follows:
(1) In electrolytically polished Ag-5.7 wt%Al and Ag-6.5 wt%Al alloys just after quenching from 550°C into iced water, many thin striations were observed. But such striations were not observed in Ag-3.0 wt%Al, Ag-5.0 wt%Al and Ag-7.7 wt%Al alloys. Mechanical polishing of the former two alloys after quenching increased the number of the striations. In the latter three alloys the striations also appeared when they were mechanically polished after quenching. The formation of the striations was found to correspond to the appearance of the cph diffractions of X-ray.
(2) In Ag-5.7 wt%Al alloy which was quenched and aged at 230°C, fresh striations which were thinner than those in as-quenched alloys were observed. The fresh striations are considered to be a metastable cphζ′ phase. As the ageing proceeded, the equilibrium μ phase precipitated on these striations and in the grain boundaries.
(3) In Ag-5.7 wt%Al alloy, from the beginning of ageing at 300° or 400°C, growth of the equilibrium μ phase from the grain boundaries in to the grain as well as on the striations was observed. With growth of the μ phase the remaining striations disappeared gradually.
(4) Both the precipitations of the ζ′ and μ phases brought about an increase in hardness and electrical resistivity.View full abstractDownload PDF (2638K) -
Atsushi Takei, Hiroko Takaishi1968 Volume 32 Issue 12 Pages 1221-1228
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe oxidation behaviors of three kinds of 80Ni-20Cr alloy containing 0.1 and 0.01%Be and without Be, respectively, were studied over the temperature range of 900°∼1200°C in the atmosphere. Oxidation tests were carried out by the repeated heating method and also by the continuous heating method. The oxidation products on these alloys were observed by means of metallography, X-ray diffraction, electron diffraction and electron probe microanalysis.
It has been shown that the addition of 0.1%Be is effective to prevention of the high temperature oxidation below 1100°C. It decreases the oxidation rate and prevents the spalling of the protective oxide scale during the heating and cooling cycle. The 0.1%Be alloy forms a dense, uniform oxide layer that is composed mainly of Cr2O3 and also a subscale that penetrated along the grain boundaries of alloy into the matrix from the oxide layer.View full abstractDownload PDF (3357K) -
Atsumi Ohno, Tetsuichi Motegi1968 Volume 32 Issue 12 Pages 1228-1232
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of purity, overheating, cooling, the formation of oxide films, the addition of nonmetallic powder and vibrations, on the undercooling of Sn and Bi in a vertical shaped glass container were studied. A great defference between the undercooling behaviours of metals of 99.9% and >99.999% was found. Undercooling of 99.9%Sn and Bi increased in steps as the degree of overheating increased. It was also found that the effect of vertical vibrations on the undercooling was much greater than that of horizontal vibrations. The effect of vibrations was greatly increased by the addition of nonmetallic powder.View full abstractDownload PDF (1252K) -
Wataru Suëtaka1968 Volume 32 Issue 12 Pages 1233-1237
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSInfrared spectra of chemical conversion coating films of aluminum produced by the Modified Bauer-Vogel (MBV), the Alrok and the Alodin processes were investigated by means of the transmission, the high sensitivity reflection and the conventional specular reflection methods. The spectra of these inorganic films obtained by the reflection methods were generally in agreement with that of the transmission method, although moderate band shifts and the change in relative intensity occurred in the spectra of phosphate films obtained by the high sensitivity reflection method. The measurement of spectrum with the reflection methods can thus be employed, with some caution, for studying the composition and the structure of inorganic films formed on metal surfaces.
The absorption spectra of the films obtained by the MBV and the Alrok processes showed strong absorption bands at 1500 and 1385 cm−1, which can be assigned to the vibration of CO32− ion in basic carbonate. A continuous absorption appearing in the region of 1100∼500 cm−1 in the spectra of the same films is considered to be due to Al2(CrO4)3. These facts clearly indicate that the films do not consist of oxides, compounds supposed by many investigators, but consist mainly of basic carbonate, probably of aluminum, and aluminum chromate.
The surface film obtained by the Alodin process is composed substantially of phosphates of Cr and Al. This film also contains a small amount of sodium chromate or chromate ion physically adsorbed in the film.View full abstractDownload PDF (1937K) -
Kunihiro Mori1968 Volume 32 Issue 12 Pages 1237-1242
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSExperiments were carried out on graphite precipitation and dissolution of carbon in ordinary malleable iron castings and malleable iron castings with spheroidal graphite.
The results obtained are as follows:
(1) Graphite is not present in the as-cast state of the ordinary malleable iron castings, while numerous spheroidal graphite nuclei were observed in the malleable iron castings treated with a spheroidization agent and graphite spheroids precipitate by the same heat treatment as that of the malleable iron castings.
(2) The first stage of graphitization is accelerated by the addition of the spheroidization agent.
(3) Marked deoxidation by the addition on the spheroidization agent was not observed, but there was a slight increase in oxygen content.
(4) Only one white core is usually observed at the center of the graphite spheroid in nodular iron. However, since the white core in this cast iron is due to decomposition of the cementite which has been drawn in during graphitization, one to several white cores are observed in different locations and shapes.
(5) As the contact surface of graphite spheroids with iron is smaller than that of tempered graphite, the diffusion velocity of carbon in the spheroidal malleable iron is faster than in the case of malleable cast iron if the conditions are the same. But it appears that the difference in velocity disappears as the temperature becomes higher.
(6) Dissolution of graphite in the spheroidal malleable iron is faster than in the case of malleable cast iron when held at 1200°C and the surface oxidation is greater.View full abstractDownload PDF (3751K) -
Kunihiro Mori1968 Volume 32 Issue 12 Pages 1243-1245
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSExperiments were carried out on graphite spheroids by means of X-ray microprobe analysis and electron photomicrography. The results obtained were as follows:
(1) The presence of Ce and Mg in graphite spheroids and in their vicinity was investigated and it was found that there was no place in which they were present in concentrations over 0.1%.
(2) Spheroidals graphite nuclei which can be observed in the as-cast state of white iron castings were spherical when observed with an electron microscope and indicated an interesting structure when compared with after-annealed graphite spheroids.
(3) The white cores in graphite spheroids is due to decomposition of cementite which has been drawn in during graphitization, but it has been shown as a result of investigation of the distribution of C, Si and Fe that the white core of the sphere is rich in Fe, and a small amount of Si was detected. Also, the white core can be observed by back scattering electron and its presence can also be confirmed by electron photomicrography.
(4) The size of the graphite spheroid is approximately the same as that of nodular iron and is about 20∼60 μ.View full abstractDownload PDF (450K) -
Toshio Katagiri, Nobujiro Takamoto1968 Volume 32 Issue 12 Pages 1245-1249
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAs the first step to study the mechanism of the reaction in gas boronizing of iron with BCl3 and H2, the boronizing by BCl3 alone carried with argon or nitrogen was investigated. The obtained results were as follows:
(1) The porous and brittle boride layer which had a plane boundary against the matrix was obtained. And from the X-ray diffraction it was observed that the boride layer consisted of Fe2B and α-iron.
(2) The relationship between the logarithm of the thickness of the boride layer and that of the boronizing time was linear. But the formation of the boride layer did not obey the rule of diffusion as the slope of the obtained straight line was about 0.8.
(3) After the boronizing reaction, scalded and colourless crystals confirmed as a FeCl2 by the results of X-ray analysis were obtained at the exhustive side of the reaction tube.
(4) From the experimental results, it was considered that the boronizing reaction in this investigation followed the reaction
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Tatsuhiko Ejima, Yasushi Watanabe, Mitsuo Kameda1968 Volume 32 Issue 12 Pages 1250-1256
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy the use of a ring type electrode made of platinum,the electrical conductivities of PbO-SiO2 binary melts ranging in composition 30 to 64 mol%SiO2 have been measured over the temperature range 800° to 1200°C. Liquid structure and structural change of lead silicate have also been estimated from the present results and the data of density, viscosity and surface tension reported in the previous papers. The results obtained are summarized as follows:
(1) The specific conductance obeys the Rasch-Hinrichsen equation, κ=Aexp(−E⁄RT), in the range of composition 35 to 50 mol%SiO2. However, in the ranges of more or less than that composition, the specific conductance shows a possitive or negative deviation from the straight line. It may probably be due to the formation of polyhedra consisting of ring type anions and Pb2+ ions and homopolar Pb-O bonds.
(2) The specific and the equivalent conductances decrease with increasing content of SiO2 and show characteristic inflections around the stoichiometric compositions of 2PbO·SiO2 and PbO·SiO2. It may indicate the structural change in these compositions by the network-breaking effect of lead oxide.
(3) The heat of activation for conductance increases with increasing content of SiO2 and shows a characteristic plateau in the range of composition 38 to 45 mol%SiO2.
(4) The heat of activation for viscous flow is smaller than that for equivalent conductance in the range of composition less than 55 mol%SiO2. It is considered that the major controlling factor for the activation mechanism changes arround this composition.View full abstractDownload PDF (2692K) -
Tatsuhiko Ejima, Yasushi Watanabe, Mitsuo Kameda1968 Volume 32 Issue 12 Pages 1256-1262
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy the use of a ring type electrode made of platinum, the electrical conductivities of PbO-SiO2-M2O and PbO-SiO2-MO ternary melts have been measured over the temperature range 800° to 1200°C. Structural change in liquid lead silicates has also been discussed on the basis of the present results and the properties of alkali and alkaline earth metal oxides added to the original PbO·SiO2(1:1) melt as a third component. The results obtained are summarized as follows:
(1) When the alkali metal oxide is added, the electrical conductivity increases as compared with that of the original melt bacause of the network breaking effect of alkali metal oxide. Conductance increases in the order of Li2O, Na2O and K2O in the range less than 10 mol%M2O.
(2) When the alkaline earth metal oxide is added to the original melt, the electric conductance slightly decreases at first and then increases or decreases depending on the species of metal oxide added and the range of temperature. This tendency may be explained by the independent evidence of the general loosening of structure by the addition of these oxides, such as the formation of ion-pair and the network distortion effect.
(3) The specfic conductance obeys the Rasch-Hinrichsen equation, κ=Aexp(−E⁄RT), when the alkali metal and alkaline earth metal oxides are added to PbO·SiO2 melt.
(4) The logarithm of specific conductance and the apparent activation energy for conductance can be expressed as linear functions of the ionic radius of metal cation and the ionic strength, respectively.
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where r is the ionic radius of metal cation and I is the ionic strength.
(5) The change in conductance observed in the current investigation can well be explained in terms of the structural change in the melt and the properties of metal oxide added.View full abstractDownload PDF (2698K) -
Tasaburo Nishioka, Yukio Yasukuni, Takeshi Nishioka1968 Volume 32 Issue 12 Pages 1263-1265
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn diesem Aufsatz wurde Einfluss von Wärmebehandlungsart, Anlassen nach Ziehen und Biegetemperatur auf die Änderung des Drahtdurchmessers bei der Biegeverarbeitung von wärmebehandelten, gezogenen oder vorgereckten Stahldrähten untersucht.
Von diesen Ergebnissen wurde es bekannt, daß im Wärmebehandelten Draht der Drahtdurchmesser durch Biegeverarbeitung abnimmt, während im gezogenen oder vorgereckten Draht es durch starkes Biegen abnimmt und durch leichtes Biegen zunimmt.
Die Abnahme des Drahtdurchmessers durch Biegen ist maximal beim weichgeglühten Draht unter verschiedenen wärmebehandelten Drähten und wird stärker mit steigender Temperatur beim Anlassen des gezogenen Stahldrahtes oder beim Warmbiegen des Stahldrahtes.
Dagegen ist die Zunahme des Drahtdurchmessers durch Biegen maximal beim bleipatentiert gezogenen oder vorgereckten Draht und wird grösser mit sinkender Temperatur beim Anlassen oder Warmbiegen.View full abstractDownload PDF (1249K) -
Yoshihiro Saito, Soji Nenno1968 Volume 32 Issue 12 Pages 1266-1269
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCleavage cracks were introduced into W thin foils at room temperature. The crystallography of crack propagation was studied and dislocations near crack were examined by transmission electron microscopy.
Trans-crystalline and intergranular cracks were observed. The trans-crystalline cracks propagated mainly in the {110} type plane. The cracks in the {110} type plane were smooth, but cracks in non-principal planes were not smooth. There were observed many cracks whose tips were high in dislocation density. Slip traces were observed near cracks.View full abstractDownload PDF (1969K) -
Hideo Takei, Keijiro Nakasa, Yoshitoyo Yoshinaga, Hironori Sasaki, Ats ...1968 Volume 32 Issue 12 Pages 1270-1275
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTensile tests at high temperatures and creep rupture tests of the ausformed 9%W-2.5%Cr tool steel (SKD 5) were carried out, and the data were compared with those of the same steel heat treated conventionally.
The results obtained are as follows:
(1) The ultimate tensile strength of the 60, 40 and 20% ausformed steel and the conventionally heat treated steel are smaller in that order up to the testing temperature of 700°C. The ultimate tensile strength of the ausformed steels do not decrease remarkably until 500°C, while that of the conventionally heat treated steel decreases remarkably from 400°C, and the ultimate tensile strength of both steels become nearly equal at 700°C. The elongation of the ausformed steels are a little smaller than that of the conventionally heat treated steel, and those of both steels decrease gradually up to 300°C, but begin to increase with increase in testing temperature.
(2) At the testing temperature of 500°C, the creep rupture strength of both 60 and 30% ausformed steels are larger than that of the conventionally heat treated steel till a creep rupture time of 1000 hours, and the 30% ausformed steel is stronger than the 60% ausformed steel after 200 hours, though it is weaker till the hour. At 600°C, the creep rupture strength of the ausformed steels are larger than that of the conventionally heat treated steel until about 50 hours. Beyond about 50 hours, however, the creep rupture strength of the ausformed steels become smaller than that of the conventionally heat treated steel. At 650°C, the creep rupture strength of the ausformed steels are rather small than that of the conventionally heat treated steel.View full abstractDownload PDF (1745K) -
Takao Endo, Tôru Aramaki, Toshio Enjyo, Masao Adachi1968 Volume 32 Issue 12 Pages 1276-1280
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSResults on tensile tests and measurements of stress dependence on strain rates for pure aluminium and binary aluminium alloys over the temperature range of 300°C to 600°C are reported. The solute concentration of Cu, Mg, Ge and Zn in the alloys is the same 0.05 at%. The flow stress is larger for the larger difference in size between a solvent atom and a solute atom. The activation volume calculated from the strain rate change tests increases with increasing temperature, and its magnitude is of the order of 3×10−19 cm3 to 4×10−20 cm3. The relationships between activation volume v and flow stress σ, and between activation volume v and test temperature T are expressed respectively as v∝σ−0.67 and v=v0exp(−Q⁄kT) in which Q is about 0.27 eV. The effect of solutes on the flow stress and the strain rate sensitivity is also discussed in terms of dislocation theory.View full abstractDownload PDF (2137K) -
Akira Yazawa, Takashi Kawashima, Kimio Itagaki1968 Volume 32 Issue 12 Pages 1281-1287
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe adiabatic calorimeter used for specific heat measurements was improved for the measurements of heats of mixing. The temperature difference between the calorimeter and adiabatic blocks is kept to be zero through the P.I.D controller, in order that the heat effect which arises in the calorimeter block can be measured adiabatically. This calorimeter is conveniently applied to the measurements of various kinds of thermal data, and the evaluation of the data obtained becomes very simple.
Heats of mixing in four liquid binary systems such as lead-bismuth, lead-tin, indium-tin, indium-bismuth, were determined in the temperature range 300°C to 900°C. The results obtained for lead-bismuth system were in excellent agreement with the earlier data which had been recommended to use for the calibration of high temperature calorimeter. The results of other systems also agree fairly well with the previous data measured directly by calorimetry. Hence it is considered that the reliability of the apparatus and the method of this measurements was confirmed.View full abstractDownload PDF (2606K) -
Akira Yazawa, Takashi Kawashima, Kimio Itagaki1968 Volume 32 Issue 12 Pages 1288-1293
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy the use of a new adiabatic calorimeter, heats of mixing in the liquid binary alloys consisting of antimony and gallium, indium thallium, tin, lead or bismuth were determined at the temperatures 672°C and 730°C. The experimental data obtained were represented by following ξ function.
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Based upon the experimental results, some systematic correlations were found between heats of mixing and the periodic table. Behavior of heats of mixing seems to be explained qualitatively in terms of the electronegativity, size and valence factors. Each factor has an intimate relation with the periodic table.
Using the determined data of heats of mixing, activities were calculated for the systems in which the equations of regular solution were applicable.View full abstractDownload PDF (2022K) -
Kimio Itagaki, Akira Yazawa1968 Volume 32 Issue 12 Pages 1294-1300
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSUsing the adiabatic calorimeter, heats of mixing in the binary liquid alloys consisting of silver and aluminum, gallium, indium, thallium, germanium, tin, lead or bismuth were determined at 970°C.
The experimental results obtained were discussed in a similar way described in the previous report. It was observed that the data of heats of mixing have intimate relations with phase diagrams, suggesting that the atomic bonding in liquid silver alloys is similar to that of solid.
ξ function of silver alloys having secondary solid solutions in solid phase decreases markedly with increasing silver concentration, hence it is considered that interaction energy depends considerably on silver concentrations.View full abstractDownload PDF (2511K) -
Akira Suzuki, Takeshi Suzuki, Yutaka Nagaoka, Yoshihiro Iwata1968 Volume 32 Issue 12 Pages 1301-1305
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influence of the carbon content on secondary dendrite arm spacing has been examined. From the cooling curves for various locations in the end chilled ingot, the local average cooling rate during solidification is measured. It is found that over the range of the carbon contents studied, 0.14∼0.88%C, secondary dendrite arm spacing, S μ, in cast steels is independent of the carbon content but influenced only by the average cooling rate, R°C/min. The relationship for the carbon steel is S=710R−0.39. It is shown that this relationship is also valid in low alloy steel containing 1.17%Cr and 0.25%Mo.View full abstractDownload PDF (1630K) -
Mikio Nishihata, Yohta Sato, Shouichi Kato, Yoshinori Isoe, Takashi On ...1968 Volume 32 Issue 12 Pages 1305-1310
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this paper, investigation was made on the effect of long period atomospheric exposure corrosion on fatigue strength of stainless steel wire as contact spring material used for relays. The corrosion behavior of atomospheric exposure materials is different by testing locations. The material exposed in Kawasaki, a city on the coast where is a with industrial pollusions, was extremely corroded. The lightest corrosion rate was the material tested in Musashino. As regards the corrosion behavior, nickel silver wire is inferior to others and the type of corrosion is stress corrosion cracking. The corrosion type of stainless steel and nickel coating stainless steel and nickel coating stainless steel wire is pitting. Stainless steel and nickel coating stainless steel wire have fatigue strengths two or three times greater than nickel-silver wire. After the exposure, the fatigue test was performed under the fatigue limits which were obtained before the exposure. Fatigue fracture occurred at 1×105 cycle in stainless steel and nickel coating stainless steel and at 1×103 cycle in nickel silver.View full abstractDownload PDF (2545K) -
Shotaro Morozumi, Michio Kikuchi, Shigeyasu Koda1968 Volume 32 Issue 12 Pages 1311-1316
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA transmission electron microscope observation has been carried out on the crack propagation in 99.9% pure magnesium foils stretched at the inside and outside of an electron microscope. Optical and scanning electron microscope observations also have been made on fractured surfaces and cracks in holed-sheet test pieces. The results obtained are as follows:
(1) In many cases, cracking occurs at an edge of foils and is associated with the preceding slip on the basal plane. Then this initial crack, thought to be in the basal plane, changes its direction and takes a zigzag path in the deformed and thinned region ahead of the crack where heavy pile-ups of dislocations have been observed.
After this, the crack develops deviating largely from its initial direction.
(2) Sometimes, a large crack composed of two cleavage planes has been observed, for example, in a foil whose surface is pallerel to the (0001) basal plane.
(3) Cracks mentioned above can be explained by cleavage planes already reported.
(4) As a result of the heavy stress concentration due to crack propagation, the activation of slip, nucleation of a new crack, twin formation and crack propagation along the twin have been observed in adjacent grains, with grain-boundary sliding.
Nucleation of a new crack due to slip also has been observed at a distance from the tip of initial crack.
(5) The tip of crack often branches out in two fine non-crystallographic cracks which are thought to be at the top and bottom surfaces of the foil.
(6) In the holed-sheet test pieces, the mode of fracture changes from brittle to ductile according to the distance from the hole.
Dimples, in which smaller ones also have been observed, are measured to be in sizes comparable to the grain sizes.View full abstractDownload PDF (3119K) -
Jun-ichiro Yagi, Iwao Muchi1968 Volume 32 Issue 12 Pages 1316-1321
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSOn the basis of the experimental data reported by other investigators(11)(14), over-all reaction rates of the reduction of SiO2 in slag and of the water gas shift reaction are determined as a function of operating conditions and these rates are used in a mathematical model.
As shown in Eqs. (18)∼(38), the specific heat of each component of burden materials is represented as a function of temperature and these equations are used in this model.
Longitudinal distributions of process variables are determined with the aid of a computer, and in this calculation fractional utilization of H2 and fractional reduction of iron ores at the top of the bed in the blast furnace are considered. Fractional utilization of H2 at the top of the bed exerts influence on the distribution of molar fraction of H2 but the distributions of the other variables are not so much influenced by this factor.
Heat transfer coefficients determined from different empirical equations for the packed bed and for the solid particle are used in this model, and the calculated results on the longitudinal distributions of process variables under the same operating conditions are compared. Longitudinal distributions of overall reaction rates in the blast furnace are also discussed.View full abstractDownload PDF (1974K) -
Masaru Satoyoshi, Fusao Hayama1968 Volume 32 Issue 12 Pages 1322-1327
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFriction experiments have been carried out by sliding hemispherical iron specimens on flat ones at sliding speeds ranging from 1∼200 cm/sec at loads of 200∼2000 g, under various oxidative conditions. At constant load (1000 g) in air, as the speed increases the wear first increases from a very low value at 1 cm/sec to a maximum at about 50 cm/sec and then begins to decrease again. At a speed of 10 cm/sec, the wear is found to increase linearly with increasing load, and it is suggested that an adhesive wear is predominant. In such cases the coefficient of friction increases at a certain sliding distance from an initial low value due to the thin oxide film formed in air, to a high constant value. However, at a low speed or at a light load, the variation of the coefficient of friction with the sliding distance shows a peculiar pattern, i.e. the coefficient of friction increases to a maximum with large fluctuations and then decreases to a low stationary value. The reason why the friction decreases can be explained in terms of the formation of oxide film on wear traces. Another experiment in Ar atmosphere shows no formation of protective oxide film for friction. Further, when the flat specimen is heated in air, the formation of oxide is accelerated, and it is found that the oxide affords good influence on the friction and wear.View full abstractDownload PDF (2554K) -
Yasuhiko Hashimoto1968 Volume 32 Issue 12 Pages 1327-1334
Published: 1968
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPure titanium metal was electrodeposited on a cathode by double fused salt electrolysis with the cell designed specifically for this work. Electrolysis was carried out in NaCl, NaCl-TiCl2-TiCl3 and NaCl-K2TiFx baths. The anode materials for the first stage electrolysis were Ti-C-O alloys or TiC prepared by carbon reduction of oxides such as TiO2 (pigment or enamel grade), rutile ore, high titania slag in the vacuum furnace or in the electric arc furnace. The best result was obtained when TiC or high carbon and low oxygen Ti-C-O alloy was fed as the anode into the NaCl-K2TiFx bath. Under such a condition, the yield of titanium from the anode material reached 98.24% for the first stage electrolysis and 86% for the second one. A high purity (less than 95 B.H.N) was maintained thoughout the second step electrolysis.View full abstractDownload PDF (2437K)
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