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Volume 31, Issue 4
Displaying 1-50 of 58 articles from this issue
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Kô Soeno, Masatosi Tuchiya1967 Volume 31 Issue 4 Pages 305-310
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNitrogen diffusion peaks of iron alloys containing less than five atomic pct cobalt or nickel were measured with a torsion pendulum of about Ic/s and with a transverse vibration mode of about 350 c/s. Observed peaks in Fe-Co-N and Fe-Ni-N alloys are very similar to the usual nitrogen peak of unalloyed ferrite. These elements presumably do not sensibly alter the diffusion rate of nitrogen in ferrite.
Precipitation of nitrogen during isochronal annealing was investigated by the internal friction method. The results show that Fe8N phase precipitated in Fe-5 at%Co-N alloy is decreased in considerable amount. This is tentatively interpreted as the indication that the nitrogen concentration equilibrated with Fe8N is increased by the addition of cobalt.View full abstractDownload PDF (431K) -
Hideo Kayano1967 Volume 31 Issue 4 Pages 310-316
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNucleation of dislocations around inclusions in iron containing small particles of FeO, Al2O3 or Zr2O was investigated by means of transmission electron microscopy. Dislocation loops produced around inclusions by the prismatic punching were observed in iron containing FeO or Zr2O particles when annealed for 100 min at 800°C and furnace cooled. The number of loops generated from an inclusion varied from 2 to 18, and the loops occurred along close-packed ⟨111⟩ directions. These loops seemed to be produced by thermal stress arising, during cooling, from the difference in thermal expansion coefficient between the inclusion and the matrix. Generation of dislocations was also observed around inclusions and precipitates in iron deformed 2% at room temperature. The formation mechanism of prismatic punched dislocation loops was discussed.View full abstractDownload PDF (1083K) -
Hideo Kayano1967 Volume 31 Issue 4 Pages 316-322
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe nucleation mechanism of dislocation loops around inclusions in iron was discussed. The stress caused around an inclusion by thermal constriction or mechanical deformation was reduced rapidly as is apart from the inclusion. The line energies of edge and screw elements of the dislocation loop are in the ratio of 1⁄1−ν: 1 where ν is Poisson ratio. Consequently, the shape of the dislocation loop nucleated around the inclusion was considered to be semi-elliptical. The formation energy of the semi-elliptical dislocation loop arised from thermal stress and the temperature dependence of nucleation stress of the dislocation loop were calculated by the rate theory. The nucleation stress of the dislocation loop calculated from the present model is μ⁄22∼μ⁄47 at room temperature, which is consistent with the experimental observation of dislocation nucleation around the Zr2O inclusion. The elastic shear stress distribution around a spherical inclusion in an isotropic elastic medium during tension was considered. In this case, the stress concentration around the inclusion was too small to nucleate a dislocation loop. It is deduced that the residual stress around the inclusion, for example, induced thermally during the cooling plays a major role in the nucleation of dislocations by mechanical deformation.View full abstractDownload PDF (461K) -
Zenzo Henmi, Takeshi Nagai1967 Volume 31 Issue 4 Pages 322-328
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe authors investigated the rolling and annealing texture in Cu-Be alloy . The rolling texture in Cu-2%Be alloy is (110)[1\bar12] (α-Brass type) and in Cu-Be 25 alloy is explained (110)[1\bar12] but not α-Brass type. The annealing texture in Cu-2%Be, rolled 90% and annealed for 30 min at 600°C is (123)[10.1.\bar4], which is different from α-Brass type (225)[73\bar4]. Cu-Be 25 alloy rolled 75% and annealed for 30 min at 500°C is partly (110)[1\bar12] texture, which is thought Co in Cu-Be 25 alloy preventing grain boundary migration of α. Furthermore the authors investigated the texture of γ-phase in Cu-2%Be rolled 90% and annealed 30 min at 400°C, and found that γ has weak texture.View full abstractDownload PDF (1611K) -
Zenzo Henmi, Takeshi Nagai1967 Volume 31 Issue 4 Pages 329-333
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe rolling and recrystallization textures were investigated in 2-nine, 3-nine, 4-nine and 5-nine Al. It was found that the recrystallization texture of Al varies with purity. The origin of different recrystallization texture is explained by the oriented growth theory and the inverse Rowland transformation. Although there are some criticisms for these theories, the oriented growth theory seems to be able to fully explain our results. In low purity Al, impurity atoms prevent the grain boundary migration during recystallization, so that the rolling texture is preserved until the recrystallization is completed. In high purity Al, it is considered that the (100)[001] recrystallization texture is formed by the selective growth and smooth grain boundary migration. The inverse Rowland transformation is also a possible mechanism, if the stacking fault energy in high purity Al is assumed to be about 100 ergs/cm2.View full abstractDownload PDF (339K) -
Tetsuo Kato, Tadayoshi Takano1967 Volume 31 Issue 4 Pages 334-338
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSChanges in magnetic properties during aging process were measured in detail on Al-Ni-Co-Ti permanent magnet alloys. In these alloys, the reversibility of the magnetic properties in the aging process was found as in the case of Alnico 5. The results of measurements are summarized as follows:
(1) The changes in magnetic properties by aging at 650°C and 550°C are almost reversible. In the case of aging above about 650°C, the irreversibility is revealed with increasing temperature.
(2) Magnetic properties is improved by pre-aging at 650°C and subsequent re-aging at 550°C.
(3) During the aging process at 550°C, (BH)max presents a two-step change; with increasing aging time, (BH)max increases until it ceases the increase and then begins to increase again. Br shows a peak corresponding with the second increase in (BH)max.
(4) Perminvar type hysteresis loop was found after pre-aging at 800°C and subsequent re-aging at about 550°C.View full abstractDownload PDF (856K) -
Nobujiro Takamoto, Toshio Katagiri, Kyoko Fujii, Yoshio Katagiri1967 Volume 31 Issue 4 Pages 338-341
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWith the object of surface-hardning, boronizing of iron with a mixture of H2 and BCl3 gas was studied. The results were as follows:
Microscopic examination of the microsection taken from the cross-section of the specimen showed that the boride film consisting of two layers was formed above 600°C. The microhardness of the boride layer was about 2000∼2200 on the surface, 1600∼1900 in the outer layer and 1300∼1500 in the inner layer. And each layer had a little gradient in microhardness. The results of X-ray analysis showed that the outer layer was FeB and the inner layer was Fe2B, and that in each layer the C-axis of crystals grew up in a direction perpendicular to the surface.View full abstractDownload PDF (448K) -
Hisashi Suzuki, Ichiro Kawakatsu, Hitoshi Kitano1967 Volume 31 Issue 4 Pages 342-346
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStudies on the properties of copper-high zirconium-high chromium alloys containing 0.73∼1.46%Zr and 0.77∼1.93%Cr were carried out comparing with those of copper-high zirconium and copper-high chromium alloys. Results obtained were as follows:
(1) The temperatures of 950° and 450°C were found to be best suited for solution-treatment and aging of Cu-Zr-Cr alloys, respectively. Their mechanical properties such as hardness and tensile strength were extremely superior to Cu-Zr and Cu-Cr alloys. The reason may be due to the increased solid-solubility in Cu-Zr-Cr alloys.
(2) Electric conductivity of the alloys was somewhat lower than the others: however, it was found that conductivity increased remarkably by prolonged aging, affecting almost no reduction in strength.
(3) The sequence of precipitation in Cu-Zr-Cr alloys appeared to be a combination of Cu-Zr and Cu-Cr alloys. Heat resistivity and electric conductivity of the alloys could be explained in relation to those of Cu-Zr and Cu-Cr alloys.
(4) As the results, the characteristic properties of Cu-Zr-Cr alloys which are more than 60 kg/mm2 in strength and more than 80% IACS in conductivity were easily obtained.View full abstractDownload PDF (983K) -
Toshisuke Shioya, Senichi Yamada, Shohachi Inada1967 Volume 31 Issue 4 Pages 347-352
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESS“Deform-quenching” treatment improves the mechanical properties of tempered plain carbon steel. It is because the “Deform-quenching” gives an improved hardenability to the steel, but the reason why hardenability of steel is improved is not well known.
We have carried out several experiments using the following specimens of S 25 C:
(This article is not displayable. Please see full text pdf.)
The following results have been obtained from the above experiments.
(1) The softening temperature of F0-Qu in tempering is higher than that of 900Qu. The longer the specimen is kept at the temperature where the forging is completed, the lower the softening temperature becomes and approximates to that of 900Qu.
(2) In cementite neucreation temperature F0-Qu is the highest and is followed by F0-1Qu, F0-30Qu and 900Qu are nearly equal and the lowest.
(3) In F0-Qu the precipitated carbide produced by tempering at 320°C is of most fine and uniform dispersion. In F0-1Qu and F0-30Qu it is grown and concentrated to that of 900Qu.
(4) F0-Qu is the highest in dislocation density of martensite. The longer F0-1Qu and F0-30Qu are kept at 900°C after forging, the lower the dislocation density becomes and approximates to that of 900Qu.
(5) The shape of martensite leaf of F0-Qu is longitudinally short and partially curled. In the length of martensite leaf F0-Qu is the shortest, F0-1Qu second, and F0-30Qu is approximately equal to 900Qu.
It is thought that the improvement in hardenability of steel by “Deform-quenching” treatment depends upon the austenite grain growth as well as the working effect, and also that the working effect will disappear during the recovery or re-crystalization of austenite grain when the specimen is long kept at 900°C after forging.View full abstractDownload PDF (535K) -
Isao Gokyu, Kenji Hashimoto1967 Volume 31 Issue 4 Pages 352-356
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe yield point and tensile strength of steels worked at elevated temperatures (about 300°C) are higher than that of steels worked at room temperature or that of steels annealed at various temperatures after cold working. It can be considered that strengthening of steel by warm working is attributed to the strengthening of α-iron in steel; the dislocation density of α-iron worked at elevated temperatures is higher than that of cold worked or annealed after cold working because of the multiplication of dislocations due to dynamic strain aging in warm working. 0.02%C α-iron warm worked, cold worked and annealed after cold working are studied by transmission microscopy and the hardness test.
The results obtained are as follows:
(1) Both the low temperature annealing effect after cold working and the warm working temperature contribute mostly to the strengthening of 0.02%C α-iron in the same way as for other steels, so that the strengthening of mechanism of 0.02%C α-iron is considered to be the same as that of other steels.
(2) The strength of the warm-worked steel is higher than that of the steel annealed at various temperatures for various times after cold working.
(3) The dislocation density of α-iron worked at 300°C is higher than that of α-iron worked at other temperatures and annealed after cold working. The dislocation density of α-iron corresponds to the hardness of α-iron.
(4) The mechanism of strengthening α-iron by warm working is based on the increase of the dislocation density by multiplication of dislocations due to dynamic strain aging.View full abstractDownload PDF (1338K) -
Isao Gokyu, Teruo Kishi, Manabu Ogura1967 Volume 31 Issue 4 Pages 357-362
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStraightening of steel can be attained by the warm working process, i.e., the deformation of steel in the blue-brittle temperature range. In this investigation, this process was applied to the roller straightening of 0.10%C-steel.
The results are as follows:
(1) As for annealed steel, it is found that the strength of the warm-worked steel is about 30% higher than that of the cold worked steel.
(2) The high strength of the warm worked steel is due to both the increase of work hardening and the decrease of Bauschinger’s effect. The latter is especially important in straightening and is attributable to the formation of the Cottrell atmosphere of piled-up dislocations.
(3) As for 60% pre-drawn wire, it is found that the strength of the cold-worked steel decreased, but that the strength of the warm-worked steel increased. There is little work hardening at the cold working temperature, but at the warm working temperature there exists considerable work hardening. The high strength of the warm-worked steel is due to this phenomenon together with the decrease of Bauschinger’s effect.View full abstractDownload PDF (954K) -
Isao Gokyu, Junji Kihara1967 Volume 31 Issue 4 Pages 363-367
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been found that the deformation mechanism of iron at high strain rates of 102∼103/sec and at elevated temperatures from room temperature to 500°C seems to be the same as the one at lower temperatures and lower strain rates. However, the following two problems must be considered to make clear the deformation mechanism of iron under both deforming conditions. The one is whether the deformation of iron obeys the mechanical equation of state and the other is whether the deformation mechanism is affected by the presence of interstitial impurities such as carbon and nitrogen.
The authors deformed iron and steel both by a creep tester at strain rates ranging from 10−6 to 10−4/sec and by a tension tester at strain rates ranging from 10−3 to 10−2/sec. The content of carbon plus nitrogen in the specimens varies from 0.02% to less than 1 ppm. The specimen with less than 1 ppm carbon plus nitrogen was made of 0.02% carbon steel by wet hidrogen annealing.
The results are as follows:
(1) At strain rates of 10−6∼10−4/sec and below 250°K the stress and the temperature dependence of strain rate of iron is not substantialy affected by the presence of carbon or nitrogen. Therefore, neither carbon nor nitrogen is considered to have any effect on the deformation mechanism in iron.
(2) The deformation of iron obeys the mechanical equation of state at least below 295°K and at low strain rates.View full abstractDownload PDF (928K) -
Isao Gokyu, Junji Kihara1967 Volume 31 Issue 4 Pages 368-373
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the previous paper, it has been concluded that the interstitial impurities do not affect the flow mechanism of iron and steel. However, since the study was mainly performed by the creep test, we could not decide whether the flow mechanism was composed of one process or more than two, nor find, how the activation energy depended on the applied stress, if the mechanism was a single activated process.
By using an Instron-type testing machine which allows to change strain rate during deformation, we studied the temperature and strain-rate dependence of the flow stress of iron and steel containing carbon and nitrogen between less than 1 ppm and 0.07%.
The results obtained are as follows:
(1) The mechanism is a single activated process for the effective stress of more than 2 kg/mm2.
(2) This process does not depend on the interstitial content or strain.
(3) It is reasonable to consider that the process is the double-kink formation as proposed by Conrad, but the 0-stress activation energy is 0.20∼0.25 eV higher than his value. This discrepancy is mainly due to an approximation, ie. ∂τ⁄∂ln\dotγ\simeqΔτ⁄Δln\dotγ, made in his calculation. His approximation is not valid when the effective stress τ is small or Δτ is as large as 5 kg/mm2.View full abstractDownload PDF (481K) -
Isao Gokyu, Munetsugu Matsuo1967 Volume 31 Issue 4 Pages 374-380
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSingle crystal sheets of a 3%Si-Fe alloy with (110)[001] and (551)[1,1,10] orientations were rolled at room temperature to 45, 65 and 85% reduction in thickness. The changes in texture upon recrystallization of various components of the rolling texture was studied at some stages of annealing at 650° and 850°C. Primarily recrystallized grains are analyzed from Frank’s formula to be in the orientations which are derived from rotations due to dislocations of operative slip systems during cold rolling. The dependence of recrystallization textures upon annealing conditions is considered in terms of the difference of the recrystallization tendency among matrices of different rotation systems. Recrystallized grains are found to have a small growth rate in the matrices where the rotation due to their dislocation structure is different from that relating the matrices and the recrystallized grains, even if the rotation is 27° about the ⟨110⟩ direction which has been presumed to be favourable for growth. The nucleation and growth of recrystallized grains is concluded to be affected by the dislocation structures and the crystal rotations due to them.View full abstractDownload PDF (682K) -
Tadayuki Nakayama, Tatsuya Koizumi1967 Volume 31 Issue 4 Pages 380-385
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSOxide films formed on titanium in high temperature water, saturated steam, and super-heated steam at various temperatures were examined by the electron diffraction technique, and two modifications of TiO2, anatase and rutile were detected. Oxide films formed after keeping either in high temperature water or saturated steam at 300°C for 2 hr were found to take a double layered structure, which was composed of an outer layer of anatase and an inner layer of rutile. In super-heated steam, the quantity of anatase decreased with decreasing degree of super-heat. It was thus clarified that the existence of water in oxidizing environments resulted in the formation of anatase. The differential thermal analysis data for anatase-rutile transformation showed a sharp exothermic peak at 1110°C, and suggested that the anatase modification is a metastable phase, while the rutile modification is stable in the whole temperature range.View full abstractDownload PDF (465K) -
Tadayuki Nakayama, Yasushi Watanabe1967 Volume 31 Issue 4 Pages 385-389
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe authors studied high temperature oxidation behaviours of 18 wt%Cr-Fe system alloys, which contain 0.09∼0.98 wt%Si and 0.042∼0.894 wt% rare earth elements (added as Ce rich mish metal), in air at high tempratures (1000°, 1100°, 1200°C; 6 or 24 hr). The addition of those small alloying elements resulted in the remarkable improvement of high temperature oxidation resistance. In order to clarify the effects of rare earth elements on the behaviours of Si during oxidation, the distributions of alloying elements and the structures of oxide layers on the alloys were studied with X-ray diffraction and electron probe microanalysis methods. The oxidation resistance of the alloys was improved with increasing amounts of rare earth elements and Si. From the results of electron probe microanalysis and X-ray diffraction, the protective mechanism was explained by the accumulation of Si at the interface between Cr2O3 layer and metal substratum. The X-ray diffraction patterns obtained from the oxide layers of the alloy containing 0.42 wt%Si and 0.894 wt% rare earth elements after the oxidation at 1100°C for 24 hr and 1200°C for 6 hr showed the existence of the α-cristobalite phase, besides Cr2O3. However, the accumulation of rare earth elements were not detected at the interface or oxide layers. Therefore, it is concluded that the addition of rare earth elements accelarates the outward the diffusion of Si to the surface, and that the SiO2 layer thus formed contributes to the oxidation resistance of the alloys.View full abstractDownload PDF (376K) -
Naoto Asami, Masao Yamada, Shuichiro Takahashi1967 Volume 31 Issue 4 Pages 389-394
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe electrical resistance changes of uranium metal during the transformations between the α(orthorhombic), β(tetragonal), γ(body-centerd cubic) and liquid phases have been studied quantitatively up to 80 kb, 1200°C in cooling and heating at rates of 2°∼4°C/sec by utilizing a modified girdle type apparatus. The samples were monitored by thermocouples and potential probes. The P.T. locations of the (α,β), (β,γ), (γ, liq.) and (α,γ) phase boundaries, and (α-β-γ) triple point were determined. The equilibrium (α-β-γ) triple point was placed at 29.8±1.2 kb, 798±5°C. The hysteresis intervals at the heating and cooling runs for α-β, β-γ and α-γ transformations under high pressures were about 33°C, 21°C and 17°C respectively, and these values were nearly the same as the hysteresis expected at zero pressure.
The initial slope of (α,β) and (β,γ) phase boundaries agreed well with the calculated T. vs. P curve based on the zero pressure thermodynamical consideration. The volume change accompanies with melting was calculated as 0.49 cm3/mole from the initial slope of (γ, liq.) phase boundary.View full abstractDownload PDF (1022K) -
Hirozo Kimura, Yasuo Sasaki, Shigeaki Uehara1967 Volume 31 Issue 4 Pages 395-400
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSReactions of compounds in the Nb-C-O system with CO or CO2 were investigated. Reactions of solid phases, such as Nb, NbO, NbC and Nb2O5, with CO, CO2 or a mixture gas of CO and CO2, up to 1400°C were studied by the measurement of weight changes, X-ray analysis and chemical analysis. In the reactions of Nb or NbO with CO, mixtures of NbO2 and NbC were obtained as final products according to the following gross reactions: 3Nb+2CO→2NbC+NbO2…(4) and 3NbO+CO→2NbO2+NbC…(2). In the case of Nb2O5 with CO, NbO2 was obtained as a reduction product by the following equation, Nb2O5+CO→2NbO2+CO2…(3). Little weight change was observed in the reaction of NbC with CO. CO2 acts as an oxidizing agent and Nb2O5 was obtained in all cases with the CO2 reaction.
Carbon and oxygen increased during the arc melting process in CO atmosphere in the specimen containing more than 80 at% niobium. Excepting the above case, carbon and oxygen were found to decrease in most specimens during the arc melting process in CO or Ar atmosphere, and the rate of decrease is remarkable in the specimens containing oxygen and carbon at the ratio of about one to one.View full abstractDownload PDF (465K) -
Yasuo Sasaki, Hirozo Kimura, Shigeaki Uehara1967 Volume 31 Issue 4 Pages 401-405
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTensile and bending properties of niobium containing hydrogen up to 8 at% were investigated. It was found that hydrogen has a pronounced effect on elongation, yield stress and bending property of niobium.
Niobium-hydrogen alloys were made by heating niobium in purified hydrogen at 1 atm pressure at 450°C for several hours. Plate-like and lenticular hydrides were observed in all specimens used for the present experiments.
The yield stress and elongation of specimens were measured with Instron’s type test machine at room temperature, −75°C and −195°C. The yield stress increases gradually with increasing hydrogen contents. Elongation decreased with increasing hydrogen contents and Nb-2.05 at%H specimens showed 17% elongation which was a half of it in pure niobium. Bend angle tests were carried out with Chevenard’s testing machine at room temperature and a marked effect of hydrogen on the bending properties was found. The bend angle decreased abruptly to zero in alloys containing hydrogen more than 2.05 at%. Alloys containing hydrogen less than 1.63 at% showed ductile deformation in the bend test.View full abstractDownload PDF (773K) -
Tadashi Kubota, Yoshinobu Seki, Shuichiro Takahashi1967 Volume 31 Issue 4 Pages 406-412
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe microstructure changes induced by center melting and the formation of central voids in powder compacted UO2 fuel were studied by center-line heating in order to obtain some valuable informations for interpreting the data of in-pile tests which were done in parallel with this experiment.
The main results obtained were as follows:
(1) Single crystalline columnar grains and equi-axed grains were grown in the region molten during the heating process and solidified by the subsequent cooling process, while columnar graing having lenticular voids were grown in the region kept in the solid state throughout the experiment.
(2) Both types of columnar grains showed different growth patterns depending upon the change in the extent of the molten zone. When the molten zone was large, large single crystalline columnar grains were grown in the central region, while small columnar grains having lenticular voids were grown in the region surrounding the large central grains. When the molten zone was small, large columnar grains having lenticular voids were grown in the central region.
(3) The central voids were grown not only by melting-down but also by shrinkage of powder compact associated with sintering when the temperature of central region was high enough to induce the sintering of UO2.View full abstractDownload PDF (679K) -
Seiichiro Kashu, Chikara Hayashi1967 Volume 31 Issue 4 Pages 413-419
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA plasma electron beam generated from a tantalum hollow cathode source was used for melting of Ti, Zr, Mo and Ta button ingots.
The beam was operated under argon atmosphere between 1×10−3 torr and 5×10−1 torr.
Assessment of the process is summarized in the followings.
(1) The furnace chamber should be evacuated to a high vacuum in the low 10−4 torr range before starting plasma generation.
(2) The purity of argon used for the process definitely affects the quality of the buttons.
(3) Buttons obtained under argon purified by using molecular sieve and liquid nitrogen showed the same quality as ingots melted by using a high voltage electron beam.
(4) Titanium alloy containing Al and Mn was successfully melted with a smaller loss of the volatile component than the case of ordinary electron beam melting.
(5) The evaporation rate of Ti could be controlled by changing the pressure in the melting chamber.
(6) The plasma electron beam was more stable and easier in operation than with the high vacuum high voltage electron beam.View full abstractDownload PDF (472K) -
Toshinori Ôshima, Takashi Yatake, Iwao Hagiwara1967 Volume 31 Issue 4 Pages 420-424
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the previous reports it has been pointed out that the application of compressive stress during the cooling process of quench hardening of high carbon alloy steel causes the decrement of retained austenite. The hardening method which is based on this phenomenon was named “compression quenching” by the present authers.
In this paper the degree and factors of hardness increment as weel as the effects of sub-zero and aging treatment on the “compression quenching” were studied in comparison with those of normal quenching and ausforming.
The results obtained were as follows:
(1) The hardness increment of “compression quenching” was caused mainly by the decrement of retained austenite but partly by the work hardening of austenite due to the ausforming effect.
(2) The hardness of the specimen aged after the “compression quenching” was as high as that of the sub-zero treated one after normal quenching.
(3) The difference of hardness between compression and normal quenching was kept constant even after additional aging or sub-zero treatment.
(4) The hardness increment by sub-zero treated normal quenching with the additional aging treatment was larger than that by “compression quenching”.
(5) The hardness increment by ausforming compared to the same degree by “compression quenching”, required far large deformation.View full abstractDownload PDF (388K) -
Yoshiyuki Saita1967 Volume 31 Issue 4 Pages 424-428
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe carbides in commercial low-tungsten tool-steels, SKS 2 (1.03%C, 0.94%Cr, 1.21%W), SKS 7 (1.12%C, 0.37%Cr, 2.13%W), SKS 1 (1.35%C, 0.70%Cr, 4.29%W) and SKS 41 (0.37%C, 1.29%Cr, 2.22%W), after austenitizing at 750° to 1200°C for 1 or 100 hr were determined by microscopic examinations and also by X-ray diffraction analysis of the residues after electrolytic separation. Only M23C6 was found when annealed isothermally at 700°C, and M6C in SKS 7, SKS 1 and SKS 41 austenitized above 800°C, whereas tungsten carbide was formed in SKS 7 above 950°C and in SKS 1 above 1050°C on austenitizing for 1 hr, respectively. Prolonged austenitizing increased the amount of tungsten carbide and lowered the temperature for its formation, with the result that a trace of tungsten carbide was found in SKS 2 austenitized for 100 hr at 950°C.View full abstractDownload PDF (885K) -
Hisasuke Takeuchi, Sadami Tomita, Makoto Ohsawa1967 Volume 31 Issue 4 Pages 428-433
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to develop new electrical contact materials, sintered Cu-W-Co and Cu-WC-Co alloys were prepared, and their life tests were carried out using a modified ASTM type testing apparatus at AC 105 V, 50 A. The results showed that the higher cobalt content gave a smaller weight loss, a lower contact resistance and a larger welding tendency as expressed by the number of welds formed. Especially in Cu-WC-Co alloys, these characteristics were remarkable and the contact resistance maintained a very low value.
Assuming that the above-stated features depended mainly on the properties of Cu-Co matrix, contact specimens of binary cast Cu-Co alloys were prepared and tested. The addition of cobalt gave an appreciable effect on the electrical contact characteristics of copper, i.e., the lowering of contact resistance and an increase of welding number were observed. These results were in good agreement with those for the sintered ternary alloys.View full abstractDownload PDF (394K) -
Masanobu Ohmori, Yoshitoyo Yoshinaga1967 Volume 31 Issue 4 Pages 433-440
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCompressive deformation resistance of a killed carbon steel with 0.14%C was investigated at −78°C and room temperature as a function of the strain rate. The nominal strain rates employed in this experiment were 2×10−4, 5×10−3, 3×10−1, 4.3 and 3.7×102 1/sec. The main results are summarized as follows:
Yield stresses and deformation resistances at three strains of 10, 20 and 30% had two strain rate sensitivities, respectively, i.e., the smaller sensitivity in the range of lower strain rates and the larger one in the range of higher strain rates. The rate sensitivity became smaller with increasing temperature and strain.
Although the sensitivity for the compressive yield stress was quite similar to that for the tensile yield stress, the sensitivity for the compressive flow stress at a given strain was considerably smaller than that for the tensile stress. This difference in the rate sensitivities for both flow stresses resulted from the remarkable decrease in the coefficient of friction at the ends of the compression test piece with the deformation speed.
The strain hardening exponent n in the equation σa=Cεαn described as a flow curve decreased with the strain rate, but it was somewhat larger, owing to the action of friction, than the exponent obtained from the tension test. The decrease in n corresponded well to that of total elongation in the tension specimen. Therefore, the decrease in n is also considered to suggest the decrease in uniform elongation with the strain rate.View full abstractDownload PDF (1573K) -
Jitsuhiko Ueda, Toshikazu Fukagawa1967 Volume 31 Issue 4 Pages 440-444
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPlain bending fatigue tests were carried out using specimens with a round notch, in order to investigate the notch sensitivity and crack propagation of a cast Al-Si-Cu alloy. Microscopic observations of the crack and fracture surfaces were made during the tests.
The results are summarized as follows:
(1) The material had rather small notch sensitivity in regard to the fracture strength at 107 cycles. Its round notch factor was assumed to be less than 1.5.
(2) It was recognized that the rate of fatigue crack growth became larger as the applied stress was higher.
(3) Microscopic observations of the specimen surface showed that the fatigue crack tended to propagate mainly along silicon.
(4) On the fracture surface typical fatigue striations were observed in the α phase and a river pattern in silicon. Striations observed near silicon were different from those in the other region of the α phase.View full abstractDownload PDF (769K) -
Susumu Yoshida, Norio Nagata1967 Volume 31 Issue 4 Pages 444-449
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe dynamic deformation behaviour of zinc single crystals (99.99% purity) with various orientations has been investigated by compression tests at room temperature using a bar-bar type impulsive loading apparatus. In this experiment, a cylindrical specimen which is sandwiched between two slender steel bars is compressed rapidly by transmitting a rectangular stress pulse generated by the impact of a bar. Strain rates studied were of the orders of 102 sec−1 for the dynamic test and 10−4 sec−1 for the static test.
Crystals whose specimen axes are nearly in parallel with the c axis are deformed by twinning from the beginning of deformation. It is found that the density of twins is far larger and the size of them is far smaller for the dynamically deformed specimens than for the statically deformed ones. Crystals whose axes are roughly perpendicular to the c axis are deformed by nonbasal slip which is found to be on the {11\={2}2} pyramidal planes. The stress-strain curves for the dynamically deformed specimens show apparent yield points and their initial work-hardening rates are lower than those for the statically deformed ones. Crystals with orientations in the region between the above two orientations are deformed almost exclusively by basal slip. The critical resolved shear stress and the flow stress for basal slip are found to be much larger for the dynamic test than for the static test.View full abstractDownload PDF (1150K) -
Masao Ibaraki, Taira Okamoto1967 Volume 31 Issue 4 Pages 450-454
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe authors have previously shown that the dendritic structure in columnar crystals of binary alloys with low solute contents has a relation to the growth condition and the solute content. It was examined, using unidirectionally frozen Al-Cu alloy, whether the relation held in the range of higher solute contents. The results obtained are as follows:
(1) The morphology of dendrite branches, which grow in the {100} plane parallel to the freezing direction from the stalk, changes from “platelike” to “rodlike” with increasing solute content. (2) The size of dendritic cells is inversely proportional to the square root of cooling rate in a solid-liquid coexisting region, and proportional to the square root of solute content. However, the proportionality between the cell size and the solute content does not hold for the higher solute content. (3) The arms-spacing decreases gradually at first and then rapidly with increasing solute content. Even for an alloy with a high solute content the arms-spacing is inversely proportional to the fourth root of cooling rate in the solid-liquid coexisting region. These results were discussed in respect to the behavior of solute during freezing. It is concluded that the transition from “platelike” to “rodlike” may be related to the constitutional supercooling which has a tendency to increase with increasing solute content, and that the results of (2) and (3) may be related to the transition from “platelike” to “rodlike”.View full abstractDownload PDF (1181K) -
Tasaburo Nishioka, Yukio Yasukuni, Takeshi Nishioka1967 Volume 31 Issue 4 Pages 455-459
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDie Forschung über die sternförmige Bruchfläche, die beim Zugversuch an Drahtprobe aus Kohlenstoffstahl auftritt, ist bisher nicht veröffentlicht worden. Jedoch ist es zu vermuten, daß die sternförmige Bruchfläche in enger Beziehung zu den mechanischen Eigenschaften des Stahldrahtes steht. Deshalb wurde diese Forschung um die Versuchs- und Herstellungsbedingungen zum Auftreten der sternförmigen Bruchfläche, die Beziehung zwischen der sternförmigen Bruchfläche und den mechanischen Eigenschaften, und die Ursache seines Auftretens zu erklären durchgeführt.
Nämlich wurden Stahldrähte mit 0.1 bis 0.8%C patentiert und dann bis zu verschiedenen Draht-durchmessern gezogen. Über diese Drahtproben wurden die Bruchfläche beim Zugversuch und die verschiedenen Eigenschaften geprüft. Diese Ergebnissen sind wie folgt.
Die sternförmige Bruchfläche ist mit abnehmender Zuggeschwindigkeit und Einspannlänge leicht aufzutreten. Mit zunehmendem Ziehgrad und Zugfestigkeit tritt es bis auf eine Grenze leichter auf, und darüber wegen einer hohen Sprödigkeit des Drahtes bietet sein Auftreten grössere Schwierigkeit. Grosse Einschnürung hat Neigung, die sternförmige Bruchfläche leicht aufzutreten. Nämlich ist es uns klar geworden, daß der starke und zähe Stahldraht die sternförmige Bruchfläche leicht aufzutreten ist.
Es folgt daraus auch, daß die sternförmige Bruchfläche sowohl auf der Unterschied zwischen der Festigkeiten in Längs- und Querrichtung, die infolge des Formänderungsgefüges an Bruchstelle durch Ziehen und Einschnürung eintritt, als auch auf der Zunahme der Tangentialspannung durch Einschnürung beim Bruch beruht.View full abstractDownload PDF (575K) -
Noboru Matsumoto1967 Volume 31 Issue 4 Pages 460-465
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe oxygen content in liquid iron with 1∼3%C in equilibrium with carbon monoxide of 16, 8, 4 and 1 atm was studied at 1500°C.
The results obtained are as follows:
(1) The feature of dependence of K1′(=Pco⁄%C×%C) on %C varies with Pco when K1′ is calculated using the analytical value of oxygen which is determined by the vacuum fusion method. That is, when Pco=1 atm, K1′=constant in the range of carbon concentration studied. On the other hand, in the case of Pco=16 atm, K1′ increases with increasing %C.
(2) It is considered that the above-mentioned feature is based on the existence of systematic errors included in the analytical values of oxygen. The error amounts to 5∼10 ppm and is considered to originate from the oxide film on the surface of the specimens.
(3) After the correction for the systematic error, the value of K1′ is 1700 and 3000 at 2 and 3%C respectively, which is larger than the value of about 500 at %C→0 reported in literatures.
(4) The activity coefficient of oxygen in the liquid iron f0 increases with increasing %C, corresponding to e0(C)=0.1.View full abstractDownload PDF (439K) -
Koichi Nakajima, Fumiko Yamamoto1967 Volume 31 Issue 4 Pages 465-469
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMicro-hardness tests were carried out with low Cr and Mo steels in the temperature range of 20° to 150°C, and the result showed that the hardness first decreased rapidly and then gradually with temperature, the decrease amounting to about 15% at temperatures of the order of 20° to 80°C.
Fracture phenomena by an impact testing were investigated by using X-ray and electron microscopy. The results showed a transition of the mode from brittle to ductile fracture in the temperature range where a rapid decrease of the micro-hardness is shown.
It was concluded from these results that the mode of fracture was related closely to the variation of the micro-hardness with temperature.View full abstractDownload PDF (1541K) -
Genjiro Mima, Masaharu Yamaguchi, Junzô Takahashi1967 Volume 31 Issue 4 Pages 470-475
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBinary Fe-Cr alloys containing about 15∼80 at%Cr show a considerable change in properties such as electrical resistivity and hardness after aging in the vicinity of 500°C and it is considered that the change in properties arises from the formation of a coherent precipitate due to the occurrence of a miscibility gap in the Fe-Cr system below about 550°C.
In the present study aging behaviors of Fe-24%Cr, Fe-17%Cr-7%V and Fe-12%Cr-12%V alloys around 500°C have been investigated by measuring mechanical properties and electrical resistivity at liquid nitrogen temperature in order to investigate whether the miscibility gap exists in the ternary Fe-Cr-V system as observed in the binary Fe-Cr system.
It is found that the hardness and the electrical resistivity of these alloys increase with increasing aging time and the recovery of resistivity of the aged alloys takes place around 600°C during continuous heating.
On the bases of this work it is suggested that the miscibility gap in the binary Fe-Cr system is extended into the ternary Fe-Cr-V system.View full abstractDownload PDF (2245K) -
Ishi Miura, Hisao Honma1967 Volume 31 Issue 4 Pages 475-480
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSRecently, extensive studies have been carried out on the particle dispersion strengthened alloy in which particles are uniformly dispersed into matrix. Also, a successful development of FRP has been reported, and it is of great interest to study the composites containing fibers instead of particles. In this report, the results of the tensile test on the aluminum composite containing tungsten fibers (diameter=500 μ, 200 μ, 50 μ and 25 μ) and nichrome fibers (diameter=500 μ) are described. In any study of this nature, the preparation of specimens is a very important problem and one of the advantageous features of this report is that the specimens are prepared by foil metallurgy. The results obtained on these specimens are as follows:
(1) For the composites containing continuous fiber, the way of strengthening was found to be similar to that in many reports so far published. The value for the critical fiber volume percentage was 0.8% for the tungsten fiber and 0.5% for the nichrome fiber. Such a comparatively lower percentage was one of the characteristics of this type of composites.
(2) Considerable strengthening was also found on the composites containing discontinuous fibers. Various values were calculated from the experimental values. The values for the critical length of fibers were found to be unexpectedly longer, suggesting a more complicated strengthening mechanism. The strengthening factor for the discontinuous fiber κ is 0.22, 0.13 and 0.13 for the tungsten fiber with a diameter of 200 μ, 50 μ and 25 μ, respectively, and the value of κ in this case is κ=σf′⁄σf=1−lc⁄2l where σf=tensile strength of fiber, σf′=value of specific strengthening effect for discontinuous fiber, lc=critical length of fiber and l=length of fiber.View full abstractDownload PDF (1126K) -
Yasuhiko Miyoshi, Satoshi Kado1967 Volume 31 Issue 4 Pages 481-485
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFe-Al, Fe-Cr and Fe-Si alloys were internally oxidized at 800°∼1050°C in a H2/H2O mixture which was adjusted not to oxidize Fe into FeO. The character and the depth of the subscale formed were investigated with an optical microscope, and the distribution of alloying elements with E.P.M.A.
The results are summarized as follows:
(1) The character of the subscale can be classified into 5 types. The types depend on the heating temperatures, kinds and concentrations of alloying elements, and not on the surface oxygen partial pressure.
(2) Generally, the depth of the subscale is proportional to the biquadratic root of the surface oxygen partial pressure and is inversely proportional to the square root of the concentration of alloying element.
(3) Alloying elements are enriched in the subscale formed at low oxygen partial pressure.
(4) No subscale was found in Fe-Si alloys heated at 850°C in H2 of a fairly low dew point. That is probably because, as a result of the enrichment, the precipitated oxide particles have become a compact layer to hinder the diffusion of oxygen.
(5) The diffusion coefficient of oxygen through internally oxidized iron at 850°C was found to be 2∼3×10−8 cm2 sec−1.View full abstractDownload PDF (1713K) -
Sakae Takeuchi, Toshio Honma, Tsuneo Satow, Keiji Koyama1967 Volume 31 Issue 4 Pages 486-491
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe amount of addition of flux CaCl2 gives a singificiant effect on the yield of Th metal by Ca-reduction of ThO2. In order to clarify the role of CaCl2 in the Ca-reduction process, the defference in reducing rates of ThO2 by molten Ca and by saturated Ca in CaCl2, solubilities of Th, ThO2 in CaCl2 and molten Ca at 950°∼1050°C, have been examined. Furthermore, the distribution of each component (Th, ThO2, Ca, CaCl2, CaO) in reduction cake has been observed and the effects of briquetting and of stir of charge on the yield of Th have been examined. The results obtained are as follows: (1) The solubility of Th in CaCl2 at 950°C is very small (about 35 ppm), and that of ThO2 is nearly nil. (2) The reduction of ThO2 by saturated Ca in CaCl2 is more dominant than that by molten Ca, possibly due to the difference in removing rates of the CaO layer by two reducers. (3) The reducing power of Ca dissolved in CaCl2 decreases rapidly with decreasing Ca content. (4) The solubility of Th in molten Ca at 950°C is about 400 ppm. (5) The reduction cake is very porous and the distributions of Th, ThO2, CaCl2 do not show clear regularity, possibly due to high viscosity of charge at reduction temperature. (6) The briquetting of charge is effective in improving the yield of Th, especially in the shortening of the reduction time at relatively low temperatures. (7) The stir of charge at the reduction temperature is not effective for improvement of the yield.View full abstractDownload PDF (1832K) -
Kyuya Nagasaki, Mayumi Someno, Chou-Ming Chen, Hitoshi Tsuneyama1967 Volume 31 Issue 4 Pages 492-495
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe anodic behavior of annealed iron-aluminum alloys (3∼20%) was investigated in various concentrations of deaerated sulfuric acid solutions at 30°C by means of a potentiostat. The anodic behavior of Fe-Al alloy is similar to that of Fe-Cr alloy. When sulfuric acid concentration is high, Fe-Al (<12%) alloys have two passivities: The first passivity is due to the formation of ferrous sulphate, and the second one can be considered due to the formation of oxide film. While Fe-Al (20%) has only one passivity, and there is no formation of ferrous sulphate.View full abstractDownload PDF (688K) -
Kyuya Nagasaki, Mayumi Someno, Chou-Ming Chen1967 Volume 31 Issue 4 Pages 496-500
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe anodic behavior of annealed Fe-Co (10∼100%) alloys was investigated in sulfuric acid solution at 30°C by means of a potentiostat. The results may be summarized as follows:
(1) Fe-Co (<30%) alloys have two passivities: The first passivity is due to the formation of ferrous sulphate, and the second one can be considered due to the formation of oxide film.
(2) In the case of Fe-Co (90%) alloy and Co metal, the passivation process can be considered as follows: CO2O3+H2O=2CoO2+2H++2e.View full abstractDownload PDF (1035K) -
Renpei Yoda, Heitaro Yoshida1967 Volume 31 Issue 4 Pages 501-506
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to obtain Cr base alloys with excellent creep strength and hot workablity, about twenty kinds of alloys containing 15∼30%Fe and 5∼25%Mo were prepared by vacuum melting. The composition range in which hot working is possible by swaging was determined, and effects of Fe and Mo on the high temperature properties, deformation resistance, age hardening and bending creep properties, etc. were examined. The effect of cleanliness of the alloys on the age hardening properties, and harmful elements to the hot working were investigated.
The results obtained are as follows:
(1) The age hardening properties chiefly depend on the precipitation of the σ phase which is determined by the alloy composition and its property is retarded by raising the alloy’s cleanliness.
(2) Nitrogen affects most seriously the high temperature ductility in three elements of C, N and O.
(3) The oxidation reisting properties becomes considerably deteriorated in the composition containing more than 20%Mo in the test condition of 100 hr heating at 1000°C in air.
(4) The deformation resistance at 1100°C and 1200°C increases with increasing Mo content when the Cr content is constant, or with increasing Cr content when the Mo content is nearly constant.
(5) The composition range in which hot working is possible by swaging depends on the phase behaviour, the deformation resistance and the brittleness which are determined by the alloy’s composition.
(6) The creep property tends to be improved by raising the alloy’s cleanliness and also by increasing the Mo content when the Cr content is constant and by increasing the Cr content when the Mo content is constant. The creep property of the worked alloy is superior to that of cast alloy having the same composition and the reason is considered to be due partly to the spheroidization of Cr oxide.View full abstractDownload PDF (1564K) -
Yoshio Baba1967 Volume 31 Issue 4 Pages 507-512
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSExperiments were carried out to investigate the influence of additions of 0.01 at% to 0.2 at%Li, Be, Si, Ca, Ti, V, Cr, Mn (0.3 at%), Fe, Co, Ni, Cu (0.5 at%), Ge, Zr, Mo, Ag (0.5 at%), Cd, In, Sn, Sb, Pb or Bi on the formation of G.P. zones in Al-2.5 at%Zn-2 at%Mg alloy.
The results are as follows:
(1) Cr, Zr, V, Mo, Mn, Ti, Ca, Fe, Co or Ni does not interact with G.P. zones of Zn and Mg atoms, but decreases the rate of formation of the G.P. zones. This effect is similar to that in Al-Zn binary alloy, and it can be reasonably explained in terms of the increase in density of dislocations and in boundary area by the grain refining and especially the existence of these insoluble compounds which could act as effective sinks to cause the decrease in the concentration of quenched-in vacancies.
(2) Si, Ge or Sn does not interact with Zn atoms but form solute-vacancy complexes with Mg atoms alone. Therefore, these elements reduce the density of G.P. zones of Zn and Mg atoms, leading to the decrease in the pre-precipitation hardening.
(3) Ag, Cu, Be, Cd, Li or In participate in the G.P. zones of Zn and Mg atoms and increase their densities. In the particular, more than 0.03 at%Ag also enhances the rate of formation of the G.P. zones, and this phenomenon is explained by the faster clustering rate of Ag atoms than that of Zn and Mg atoms during quenching and the subsequent aging.
(4) It seems that Sb, Pb and Bi have little effects on the formation of the G.P. zones of Zn and Mg atoms.View full abstractDownload PDF (1078K) -
Yoshio Baba1967 Volume 31 Issue 4 Pages 513-518
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffects of 22 additional elements in the composition range of less than 0.5 at% on the precipitation phenomena at 120° to 250°C for Al-2.5 at%Zn-2 at%Mg alloys were studied from the measurements of electrcial resistivity and hardness and from electron microscope observations, and the mechanism was discussed with particular attention to the role of lattice defects. The results are as follows:
(1) The precipitation hardening of Al-Zn-Mg alloys is substantially reduced by the addition of Cr, V, Zr, Mo, Mn, etc. and this effect can be adequately explained in terms of the increase in crystal defects such as dislocations, sub-boundaries, grain boundaries and insoluble compounds formed by these additional elements, whose boundaries can act as sinks to reduce the concentration of quenched-in vacancies and also as preferential nucleating sites for the coarse precipitates when the easy nucleation of M′ (MgZn2) phase is pervented by the lack of vacancies.
(2) The addition of Si, Ge and Sn also decreases the precipitation hardening of Al-Zn-Mg alloys since they do not interact with Zn atoms but form intermetallic compounds with Mg atoms alone.
(3) On the other hand, the addition of Ag, Cu, Cd, Be and Li, or the pre-aging at lower temperatures is extremely effective on the increase in precipitation hardening of Al-Zn-Mg alloys. This may be due to the increase in the number of G.P. zones which can act as the heterogeneous nucleation center for precipitates, leading to the refining of M′ phases.View full abstractDownload PDF (683K) -
1967 Volume 31 Issue 4 Pages 518
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPlease see pdf. Wrong:1100°C Right:800°CView full abstractDownload PDF (10K) -
Nobuo \={O}hashi1967 Volume 31 Issue 4 Pages 519-525
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo clarify the origin of ridging phenomena in straight chromium ferritic stainless steels, structural studies have been performed on the commercially produced 17%Cr hot-rolled strip. It was found that specimens taken from the surface layer of the strip were completely free from ridging on tensile testing, in contrast with those from the interior which revealed the distinct ridging. It is noticed that the surface layer, when polished parallel to the rolling plane, always has the fine-grained ferrite structure, while the interior of the strip shows a banded structure on a macroscopic scale along the direction of rolling. The banded structure is composed mainly of lamellae of the elongated coarse ferrite grains inherited from the slab, and the coarseness of the structure is closely related to the “ridging grade” of the strip.
The elongated coarse grains show pronounced preferred orientations such as (001)[1\bar10], (112)[1\bar10] and (111)[1\bar10], and behave somewhat like single crystals on tensile deformation, resulting in the ridging phenomenon. The banded structure remains almost unchanged after annealing even at 900°C, presumably because of the structure thermally stabilized during and after hot-rolling. The known effects of chemical compositions or heat-treatments on ridging can be interpreted in terms of the change in the structure of the ferrite lamellae.View full abstractDownload PDF (1010K) -
Hiroshi Nakagawa, Shin-ichi Sato, Zenji Nishiyama1967 Volume 31 Issue 4 Pages 525-527
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn a previous study a face-centred cubic martensite was found in addition to the known hexagonal close-packed martensite in a quenched Ti-3%Fe alloy. By the present experiment the existence of the fcc martensite is confirmed and moreover it is found that the plane defects formerly observed within the martensite plate are due to internal twins, the twin planes being {111} and their thickness about 200∼400 Å.View full abstractDownload PDF (177K) -
Haruo Kubotera, Kazuhide Nakaoka, Toyoharu Suda1967 Volume 31 Issue 4 Pages 527-533
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFor the purpose of evaluating the influence of inclusions on the grain growth of a low carbon steel sheet of drawing quality, a simplified treatment is suggested.
Using a model of grain boundary migrating past a spherical inclusion, the interaction between the boundary and the inclusion is estimated: the interaction is considered to be generated by the change in area of grain boundary cut by the inclusion.
The relation between the distribution of inclusions and the upper limit of the radius of curvature of the grain boundary capable of migration is obtained; this upper limit is considered to be proportional to that of the mean diameter of grains.View full abstractDownload PDF (1253K) -
Haruo Kubotera, Kazuhide Nakaoka, Kaoru Watanabe, Toyoharu Suda1967 Volume 31 Issue 4 Pages 534-537
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCorrelation between the upper limit of the radius of curvature of grain boundary Ro and the mean diameter of grains was examined.
24 charges of low carbon capped steel were examined. Cold rolled samples were annealed, decarburized at 700°C, and then soaked at 750°C for 8 hours for grain growth. Distribution of tiny inclusions, the diameter of which is between 0.1 and 1.0 μ, was measured by the electron microscope.
The value of R0 correlated well to the mean diameter of grains.View full abstractDownload PDF (399K) -
Kazuhisa Okajima, Hiroshi Sakao1967 Volume 31 Issue 4 Pages 537-541
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSActivities of both components in the binary alloys can be measured by a new electromotive force method using the Synchroscope and the cell tube in which pure metal and alloy electrodes are isolated from electrolyte. At the experimental temperature the electrolyte is flowed out to both electrodes and the electromotive force is no sooner measured by the Synchroscope than the electrolyte touches with the electrodes, prior to the reaction occurring between the electrolyte and the alloy electrodes. The hum in the Synchroscope must be eliminated as perfectly as possible. The activities of molten alloys are measured accurately by using this method.View full abstractDownload PDF (1146K) -
Tohei Ototani, Yasuhiro Morooka, Yasuzi Kataura1967 Volume 31 Issue 4 Pages 542-547
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been found that nodular graphite steel may be more readily obtained in the as-cast state by addition of a suitable Fe-Ca base alloy to molten steel of hypereutectoid composition. Steels containing 0.7∼1.6%C were melted in alumina crucibles by a high frequency induction furnace. Effects of additional amounts of Fe-Ca base alloy and carbon contents on the amounts of free graphite, graphite distribution and matrix hardness were investigated. The results may be summarized as follows: (1) The structure with nodular graphite in the fine pearlite matrix is produced when silicon contents above 0.7% and carbon contents above the eutectoid composition are present. With increasing carbon content and additional amount of Fe-Ca base alloy, free graphite increases. (2) With increasing additional amount of the above alloy, steel tends to vary in matrix hardness: Steel containing 0.7∼0.8%C increases remarkably the hardness, but such an increase has not been observed in steels containing 0.9∼1.3%C. Conversely 1.6%C steel decreases the hardness. (3) For the purpose of graphitization in the as-cast state the amount of residual calcium must be maintained about 0.007 to 0.04%.View full abstractDownload PDF (1112K) -
Kenro Ikeda, Yukio Suginohara, Tsutomu Yanagase1967 Volume 31 Issue 4 Pages 547-552
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn a previous paper, studies on the effect of oxide additions for the physical properties of lead silicate melts were reported. For a better understanding of the constitution of molten silicate, the density and surface tension of molten barium silicates containing various metallic oxides as a third element have been measured in the temperature range 1300° to 1600°C. The results obtained are as follows:
(1) The molar volume resulted from the addition of mono- or di-valent metallic oxide tends to increase with increasing ionic radius of the oxide, whereas the molar volume with tri- or tetra-valent metallic oxide does not show such a tendency on the curve.
(2) The surface tension due to the addition of alkali oxides which may be completely dissociated into ions in the silicate melts increases with ion-oxygen attraction. On the contrary, the surface tension tends to decrease with increasing ion-oxygen attraction in the case of the alkaline earth oxides. At higher values of ion-oxygen attraction the surface tension decreases, indicating that those ions may form a complex anion.View full abstractDownload PDF (422K) -
Norihiko Ueyama1967 Volume 31 Issue 4 Pages 552-557
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of solution-treatment prior to cold-rolling on the textures of Al-Mn alloy 3003 was studied by the X-ray pole figure method. The following results were obtained:
(1) No marked effect of the solution-treatment on the cold-rolling textures of 3003 was observed.
(2) The recrystallization textures of 3003 were found to be composed of four preferred orientations of (110)[\bar997], (753)[6\bar4\bar7], (100)[uvw] and (hko)[001].
(3) When the heating velocity was fast, the amount of the (hko)[001] type component in the recrystallization textures was decreased by the solution-treatment before rolling.
(4) The variation of the recrystallization texture by the solution-treatment prior to cold-rolling may be attributed to the change in the distribution of precipitates and the Mn content in solid solution, which has influence on the selective nucleation or growth of the nuclei.
(5) The recrystallization texture of the (110)[\bar997] type and the (110)[001] type can by related to the (110)[\bar112] type deformation texture by the rotation of 26° and 35° around the common (110) pole, respectively.View full abstractDownload PDF (1360K) -
Hisasuke Takeuchi1967 Volume 31 Issue 4 Pages 557-564
Published: 1967
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSpecimens of sintered iron were prepared by the double-pressing method, using eight kinds of commercial iron powder, and their D.C. magnetic properties were measured. The sintered electrolytic iron powder named “Merisinter” possessed high density and excellent magnetic properties. It was noticed that the flux density depended essentially on the sintered density, while the maximum permeability varied widely according to the purity of powders.
Sintered compacts made by the single-pressing method using iron powder with addition of phosphorus, possessed high density owing to the shrinkage during sintering, especially when fine electrolytic iron powder was used. In this case, too, the flux density of compact depended on its specific gravity.
A sintered iron made from single-pressed Höganäs iron powder MH 300 with addition of 0.7%P had a magnetizing characteristic comparable to that of sintered MH 100 powder, without phosphorus addition, prepared by double-pressing.View full abstractDownload PDF (2294K)