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Volume 20, Issue 3
Displaying 1-16 of 16 articles from this issue
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T. Saga1956 Volume 20 Issue 3 Pages 121-124
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe formability of aluminium coated steel sheet becomes important in proportion as the application increases owing to its high resistance to corrosion. The author describes the work carried out on the subject in his laboratory as a result of which the corrosion test has been devised. For this sort of composite metal, the corrosion test is a better testing method than the Erichsen test. The problem of the formability of aluminium coated steel sheet prepared by the hot dipping process is the control of the iron-aluminium compound layer that forms during the coating operation. For good formability it is important that the compound layer be in the order of 5∼10μ and it may be up to 15μ if we can drop its hardness. To control this layer we must use an inhibitor or regulate the operating speed. I have found that it is an easier and a more reasonable process to use an inhibitor. We can inhibit the growth of the compound layer and drop its hardness effectively, by adding more than 3% of silicon to the aluminium bath. I also investigated the effect caused by the change in mechanical properties of the base steel, and the heat treatment or the cooling velocity of the product.View full abstractDownload PDF (731K) -
Masayoshi Tagaya, Imao Tamura1956 Volume 20 Issue 3 Pages 124-128
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe cooling curves at the surface and the center during quenching in various coolants were measured with cylindrical silver specimens of 10, 15, 20 and 25 mm in diameter. As to the center cooling curve series, the variation is not so clear and not so simple as that for surface cooling curve. The average value of “n” derived by the application of equation (1) to these cooling curves is 1.14 for the surface and 1.34 for the center. Consequently, the curves which should be designated as the mother cooling curves independent on the size of the specimen were obtained using k1 value in equation (1). Since it may be regarded that equation (4) is reasonably correct in collation with the data by W. Peter, it was intended to introduce the concept of the mother cooling curve which is utterly independent on both the size and the shape of the specimen. The value of n was also examied in its correctness.View full abstractDownload PDF (842K) -
Sadao Koshiba, Tsuneo Kuno1956 Volume 20 Issue 3 Pages 129-131
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSome kinds of shock resisting tool steel are commonly used today, one of which is Si-Cr-W steel containing about 1.0%Si, 1.2%Cr, 2.5%W. The authors studied the effect of silicon on the properties of Si-Cr-W steel containing which contains 0.53%C, 0.4%Mn, 1.5%Cr, 2.2%W, 0.5%Mo, 0.3%V as standard composition and some Mo and V. We have measured the transformation point, the hardenability, and the change of the hardness and the rate of deformation of these specimens, applying different heat treatments, and then have carried out the tensile test and the charpy impact test from room temperature to 500° of testing temperature. From the results of these investigations, we ascertained that the moderate content of 0.5∼1.00%Si increase the resistance for softening due to tempering, the hardenability and the tensile strength at the high temperature to 500°, and then decrease the rate of deformation due to tempering of about 400° after quenching from 950°, and moreover give a fine sorbite structure by quenching followed by tempering.View full abstractDownload PDF (509K) -
Yuki Shirakawa, Tôru Ôhara, Daiji Amemiya1956 Volume 20 Issue 3 Pages 131-135
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe thermoelectromotive forces of Fe-Al (∼8.2% Al), Fe-Cr (∼14.8% Cr), Fe-Al-Cr (∼6.2% Al, ∼11.4% Cr) and Cu-Ni (∼4.9% Ni) alloys were measured in the range from 100° to 800°. A thermocouple composed of a pair of Cu-1.94% Ni and Fe-6.2% Al-0.94% Cr alloys has such special characteristics that its electomotive force is almost zero from the ambient temperature to 400° and then increases, with the rise of temperature to 5.4 mV at 800°.View full abstractDownload PDF (652K) -
Sadao Koshiba, Terumi Nishinuma1956 Volume 20 Issue 3 Pages 135-138
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSHigh carbon-high chromium steel containing 1.3%C, 0.4%Mn, 6%Cr, 0.4%W is used as cold dies and magnet for various uses. The authors studied the effect of the quenching temperature on the expansion of steel subjected to subzero treatment and the change of hardness and magnetic properties due to normalizing and quenching, the effect of subzero treatment, and also the behavior of the retained austenite. The results of this experiment are as follows:—(1) The re-begin temperature of transformation shifts higher as the quenching temperature rises in the range of 800∼1000°, but the inverse is true as the normalizing temperature of more than 1100°. (2) The retained austenite after quenching changes to martensite by subzero treatment at −72°, and the magnetic saturation and the residual magnetism increase but the coercive force decreases. (3) The more of the retaind austenite decomposes to martensite as the subzero treating temperature is lower. (4) The hardness of steel increases to Rc 50∼55 by the subzero treatment after normalizing at 1150° including no quenching, but the retained austenite scarcely decomposes even at −183°.View full abstractDownload PDF (606K) -
Zingozaemon Matsuoka1956 Volume 20 Issue 3 Pages 138-142
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of KRK treatment on the precipitation in Corson alloy has been studied by measuring their strength and the following results have been obtained. KRK treatment at high temperature which the precipitation occurs, accelerates the precipitation in ordinary cold-drawn alloy. KRK treatment at such a temperature as that of low-temperature annealing increases the strength of ordinary cold-drawn alloy and so a higher strength is obtained by applying this treatment for each reduction of cold drawing. This low temperature KRK treatment does not accelerate the precipitation but the precipitation is accelerated by high temperature KRK treatment.View full abstractDownload PDF (745K) -
Ryukichi Nagasaki, Shigeyasu Koda1956 Volume 20 Issue 3 Pages 142-146
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe authors studied the age-hardening of copper alloys containing 1.4 and 1.7 percent of cobalt respectively. The specimens were kept for 45 minutes at 990°, quenched in water, and aged at 500°, 550° and 600° for various periods ranging from 1 to 8 hrs. The tensile strength, the yield strength, the elongation, the specific electrical resistance and the hardness were measured, and the structure was observed microscopically. The true stress-true strain diagrams were also determined. The results obtained are as follows:—(1) At the state of maximum hardness, the value of electrical resistance decreases indicatively. It means the cobalt, content of the matrix also diminishes, i.e. the precipitation proceeds to a considarable extent. But we could not observe, by means of an ordinary optical microscope, the precipitates in the interior of grains. But at grain boundaries. (2) The true stress-true strain diagrams can be formulated by the ordinary equation σ=Aεm, but in the long-aged specimens the curve deviates downward from the linear relationship near the fracture strain. (3) The best properties of 1.7% Co alloys were obtained by the heat treatment of tempering at 550° for 5∼8 hrs. The tensile strength is 36 kg/mm2 and the electrical conductivity is 42% of the international standard annealed copper. (4) There are no special characteristics in the process of age-hardening.View full abstractDownload PDF (680K) -
Yukô Mitani, Norihiko Nakanishi1956 Volume 20 Issue 3 Pages 147-150
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn our previous reports, it was confirmed that the Ms temperature could be determined by the dilatometric method accurately. In this report, 0.81% carbon steel was examined, and its fraction of martensite below Ms and bainite below 300°, was determined using subzero-treatment at −75° for 1 hour to remove the retained austenite, and then the C-type of its T.T.T.-diagram could be obtained. The results of the martensite fraction determination obtained by the dilatometric method were quite in agreement with that by the point counting method.View full abstractDownload PDF (666K) -
Harujiro Sekiguchi, Michio Inagaki1956 Volume 20 Issue 3 Pages 150-154
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe dimensional change due to annealing of 0.10%C steel bar cold-worked immediately after water-quenching from 650° is estimated as the algebraic sum of dimensional changes due to annealing of the specimen water-queached from 650° and it cold-worked after pre-annealing at 950°. However, the annealing temperatures ralated to the corresponding dimensional changes, for the specimen cold-worked after water-quenching and it cold-worked after pre-annealing, are not the same but there is a certain difference between them. The difference in the hardness and the microstructure of the specimens subjected to the above mentioned treatments were also observed and the same tendency as the one observed in dimensional changes was obtained.View full abstractDownload PDF (865K) -
Hiroshi Fujita1956 Volume 20 Issue 3 Pages 154-158
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBecause of extreme difficulties in catching the starting point of creep, the following method was used in the measurement of transient creep: At first, the stress-strain curve was traced at certain stress rate (\dotσ) by dropping water in the weighing machine until the appointed creep stress (σ) was reached. Then, the water dropping was stopped and the creep curve was traced from this moment. The results obtained were as follows: (1) At room temperature, creep curves were describable with ε=αtn in a wide range of strain except the initial stage. (2) The initial stage is formulated as ε=α{log(αt+1)}s approximately. The greater the \dotσ the wider this initial range. (3) The value of α does not only increase linearly with σ, but also increases considerably with \dotσ, while the value of n chiefly depends upon \dotσ, excepting a small increase with increasing σ. (4) The transient creep is mainly defined by σ and \dotσ at the begining of creep, there being no perceptible effect of the history of the specimen. (5) The degree of the development of slip in the transient creep is proportional to the gradient of the creep curve. (6) In the steady-state creep, there is no appreciable effect due to \dotσ.View full abstractDownload PDF (798K) -
N. Ohtani1956 Volume 20 Issue 3 Pages 158-162
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSConcerning various metals with body-centered cubic, face-centered cubic and close-packed hexagonal lattices, the author investigated how the bond energy W and the adsorption energy U of atomic hydrogen showed a maximum value at the distance of the nearest neighbour atoms r\doteqdot2.7 A. Then assuming the relationship between the bond energies and the lattice constants of those metals, the author also derived an experimental formula, in which the hydrogen overvoltage showed a minimum value at r\doteqdot2.7 Å, to calculate the values of the hydrogen overvoltage of various metals and alloys.View full abstractDownload PDF (619K) -
N. Ohtani1956 Volume 20 Issue 3 Pages 162-165
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe author calculated approximately the value of the bond energy of the ε-phase, an electron compound with close-packed hexagonal lattices, attributing the extremely small value of the hydrogen overvoltage of the ε-phase to the adsorption energy of atomic hydrogen and therefore the bond energy of metals at the lattice constant a=2.7 Å. Then deriving the relation among the first term of Tafel’s equation connected with the electrode metal, the bond energy of metal and the lattice constant a, the author showed the possibility of deciding the general tendency of the variation of the hydrogen overvoltage against changes in the composition of many alloys.View full abstractDownload PDF (557K) -
Tokushichi Mishima, Ryukiti R. Hashiguti, Yasuo Kimura1956 Volume 20 Issue 3 Pages 165-169
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe age-hardening process of an iron-molybdenum alloy containing 20 per cent of molybdenum was studied from the point of view of its precipitated volume set up during aging. The specimens were heated at 1,300° and quenched in the water at 30°. After quenching they were aged at various temperatures, i.e. 550, 570, 590 and 608°, for various lengths of time. Their vickers hardness, coercive force, residual induction and lattice constant were measured during the age-hardening process. The changes of these properties as a function of aging time can be expressed by Austin-Rickett formula (Equation 2). The activation energy of the aging process of this alloy is 75,600 cal/mol. The values of the velocity constants for the change of the coercive force and the lattice constant are identical with each other at the respective aging temperatures. A theoretical account is given concerning the relation between the volume of the precipitates and their measured properties. In the Fe-Mo alloy, the agreement between Néel’s theory and the results of the experiment is excellent.View full abstractDownload PDF (734K) -
Tokushichi Mishima, Ryukiti R. Hasiguti, Yasuo Kimura1956 Volume 20 Issue 3 Pages 169-173
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSpecimens of Fe-Mo 15% alloy were quenched from 1,250° in water. After quenching they were aged at the various temperatures of 590, 611 and 630°, for various lengths of time. Measurements of their initial susceptibility, coercive force and saturation magnetization were performed as a function of the aging time. The change of the coercive force during aging is almost similar to that of the saturation magnetization, that is, the volume of the precipitates. The change of the initial susceptibility is somewhat more rapid than that of the saturation magnetization. The reaction can be adequately described by the Austin-Rickett equation; p⁄(1−p)=ktn. The fractional changes, p, are also satisfied by the Johnson-Mehl equation; p=1−exp(−k′tn′). The activation energy for Fe-Mo 15% alloy is 72,000 cal/mol. The coercive force during the aging process agrees with the Néel’s theory that the coercive force is closely connected with some kind of unhomogeneity in the meterial. The ε phase precipitates in the {110} planes of the matrix.View full abstractDownload PDF (507K) -
Ryoji Watanabe, Shigeyasu Koda1956 Volume 20 Issue 3 Pages 173-176
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe grain boundary reaction phenomena were studied microscopically on Al-Ag alloys containing 15, 20, 25 and 30% Ag respectively, which were aged at 160°, 250°, 300°, 350° and 400° after quenching from the temperature of uniform solid solution. The rate of the growth of nodules of the grain boundary reaction was obtained from the estimation of the measured area of the total nodules, and the characteristics of the reaction were investigated. The results obtained are as follows:—(1) The grain boundary reaction is observed in all alloys we prepared. (2) As the content of Ag increases, the reaction increases (Fig. 1∼Fig. 5). (3) All the matrix of alloys is not completely exchanged by the nodules of the reaction. (4) The total area exchanged by the nodules which is represented by the fraction of the reacted area to the initial one, changes with the temperature of aging, and it rises to the maximum value at a certain intermediate temperature (Fig. 6). That is, when the temperature of aging is too high, the reaction does not occur. (5) Coldworking accerelates the reaction (Fig. 1∼Fig. 5). (6) The nodules of the reaction which contain perpendicularly oriented platelets of precipitate to the boundary grow anomalously large (Photo. 2, 4). (7) The lattice orientation of the nodules which is obtained from the orientation of platelets in them, is the same as the orientation of the adjacent grain bounded by a straight line (Photo. 7). (8) Some regions like the nodules of the reaction are also observed within the interior of grains after the aging proceeds (Photo. 8, 9). (9) Then we conclude that the nuclear formation of the reaction is a type ofrecry stallization which is nucleated by the effect of adjacent grain, but the driving force of the nodules is the energy dissipation with the growth of the particles of precipitate. So the γ′→γ transformation of the particles of the precipitate is not always accompanied only by the grain boundary reaction as Geisler has stated.View full abstractDownload PDF (864K) -
Masaichi Yamamoto, Satohiro Hayami, Zenji Nishiyama1956 Volume 20 Issue 3 Pages 176-180
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAluminium crystals have been examined by means of the X-ray diffraction microscopy (Berg-Barrett method) at an early stage of deformation by elongation. The X-ray micrographs taken show, in the rough, two sets of lamellae consisting of white and black bands. One set of them (lamellae K) runs parallel with the deformation bands due to kinking, and the other (lammellae Sb) corresponds to the alternated arrangement of the primary and secondary slip regions. In the primary slip region there have been found striae S1 which are parallel to the primary slip line, and in the other region, striae S2 which are parallel to the secondaryslip line. Moreover in both the regions, striae S′ are found which are approximately parallel to lamellae Sb.View full abstractDownload PDF (1131K)
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