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Volume 34, Issue 8
Displaying 1-19 of 19 articles from this issue
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Masataka Sugiyama, Akira Sato, Tatsuichi Fukusako1970 Volume 34 Issue 8 Pages 775-779
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe manufacturing conditions and subsequent work conditions were investigated for the manufacuture of clad-plate of aluminium and its alloys with the process of direct-rolling of molten metals. The main results obtained were as follows:
(1) In case of the alloys with a wide solidification range, the condition of junction between pure aluminium surface sheets and the core was good and became improved as the direct-rolling speed was decreased. In case of the alloys which showed the ripple mark defects in the surfaces, the surface sheets ruptured at a slower direct-rolling speed.
(2) By the cold-rolling of clad-plates as the subsequent work, only the surface sheets were elongated and torn off from the core. By the hot-rolling, the junction between surface sheets and the core was complete and the desired quality of clad-sheets was obtained.View full abstractDownload PDF (1897K) -
Masataka Sugiyama, Akira Sato, Tatsuichi Fukusako1970 Volume 34 Issue 8 Pages 780-785
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of plate thickness on the direct-rolling of molten metals of aluminium and its alloys was investigated, with the results summarized as follows:
(1) As the plate thickness decreased, the direct-rolled plates showed the tendency to bend, which was especially remarkable in case of the alloys with a wide solidification range.
(2) The upper limit of the direct-rollable speed related to the pouring temperature was not consistent with the low of inverse proportion to the plate thickness. Namely this limit became higher than the curve as the plate thickness became thicker and became lower as it became thinner.
(3) Irrespective of the plate thickness, the texture in the pure aluminium annealed sheets made from plates at a higher direct-rolling speed was retained rolling texture {112}⟨111⟩, {112}⟨123⟩ and {100}⟨001⟩, while in the annealed sheets from plates at a lower direct-rolling speed the texture {110}⟨001⟩ strongly developed.View full abstractDownload PDF (1646K) -
Keisuke Ikeda, Masahiko Sugiyama1970 Volume 34 Issue 8 Pages 785-791
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe combination of the slip systems necessary for the plane strain deformation can be determined by the theories proposed by Taylor and Bishop-Hill. But the resolved shear stresses of the slip systems necessary for the plane strain deformation are not always high. In crystals with such a situation, the deformation band is expected to be introduced to compensate the inactivity of the necessary slip systems with small shear stress. The orientations of the aluminium single crystals satisfying the condition mentioned above were previously determined by calculation. Some of them, having {011}, {111} and {112} as the compression plane, were prepared for the rolling experiments. Except for the {110}⟨112⟩ orientation, the idea proposed for the appearance of the deformation band was experimentally shown to be valid. Co-operation of two sets of slip systems makes the {110}⟨112⟩ crystal possible to be deformed without operation of the necessary slip systems with small resolved shear stress. Consequently, in the {110}⟨112⟩ orientation the plane strain deformation would not need the deformation band.View full abstractDownload PDF (1265K) -
Masanobu Ohmori, Yoshitoyo Yoshinaga, Hideyo Maniwa1970 Volume 34 Issue 8 Pages 791-797
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTwo kinds of copper specimens, a pure copper for industrial use and an OFHC copper, were deformed under various stress states and strain rates at temperatures between room temperature and 600°C. Both of the coppers showed an intermediate temperature embrittlement (less ductility) when deformed slowly, but showed no embrittlement when deformed rapidly. Grain boundary slidings or cracks along boundaries were produced on the surfaces of the specimens deformed in a brittle manner. On the contrary, no boundary sliding and crack were found in the specimens deformed rapidly over a temperature range in which the slowly deformed specimens revealed slidings or cracks.
From the present study, it has been concluded that the intermediate temperature embrittlement of copper may be attributed to a viscous behaviour of grain boundaries.View full abstractDownload PDF (1880K) -
Akira Suzuki, Jitsuhito Nakamura, Toshimasa Sakamoto1970 Volume 34 Issue 8 Pages 797-801
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present work was carried out so as to investigate the substructures of columnar grains in Al-Cu alloy ingots in connection with the growth conditions.
The change of substructures of columnar grains was observed in aluminium ingots under a high pressure applied during solidification. Further experiments were performed on Al-0.2, 1 and 2%Cu alloys, and it was found that columnar grains grown under a high pressure, 2,072 kg/cm2, exhibited a simpler morphology than those grown under the atmospheric pressure. And in Al-0.2%Cu ingots solidified under the atmospheric pressure, the columnar grains grew in a cellular dendritic manner in the ingot cast in the mold at 15°C, and in a dendritic manner in the mold at 500°C.
The above-mentioned change and difference in the substructures of columnar grains are hardly explainable in terms of growth parameter, G⁄V, where G is the temperature gradient in the liquid phase ahead of the freezing front and V is the growth rate of dendrite tips. However, taking G for the temperature gradient behind the freezing front, the dependence of growth morphology of columnar grains on G⁄V is consistent with the previously confirmed results.View full abstractDownload PDF (2259K) -
Akira Suzuki, Jitsuhito Nakamura, Toshimasa Sakamoto1970 Volume 34 Issue 8 Pages 802-807
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe origin of the equiaxed zone has been investigated in 99.99% purity Al and Al-0.2%Cu alloy ingots in which columnar grains grow in a cellular or cellular dendritic manner. Experiments on the conventional ingots and bottom chilled, unidirectionally solidified ingots show that there is a critical pouring temperature for the formation of equiaxed zone, above which no equiaxed zone forms. In the absence of pouring turbulence, however, no equiaxed zone forms even though the ingot is quenched from the temperature below the critical one. These results indicate that the pouring turbulence is an essential element in the formation of the equiaxed zone. It is also found that the chill grains in the very surface layer of the ingots have dendritic morphology.
So it is concluded that the equiaxed zone in pure Al and Al-0.2%Cu alloy ingots is caused by the multiplication of dendritic chill crystals induced by pouring turbulence.View full abstractDownload PDF (3125K) -
Akira Suzuki, Jitsuhito Nakamura, Toshimasa Sakamoto1970 Volume 34 Issue 8 Pages 808-813
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has previously been reported that the equiaxed zone originates from dendrite fragments of chill crystals in the ingot in which columnar grains grow in a morphology without side branches.
The present work attempts to determine the origin of the equiaxed zone formed in the Al-4%Cu ingot with dendritic columnar grains. The results show that in the ingot cast below a critical temperature for the alloy, the above-mentioned “free” chill crystal mechanism operates, and that when the pouring temperature is higher than the critical temperature, the equiaxed grains originate in remelting of the columnar dendrite.
The grain refinement of the Al ingot by titanium addition is also discussed in terms of the formation mechanism of the equiaxed zone. It is concluded that the grain refinement by titanium addition is caused by the formation of the equiaxed zone due to the “free” chill crystal mechanism, and not by the direct nucleation on the nucleating particles in the melts.View full abstractDownload PDF (3207K) -
Hironori Mine, Masanori Tokuda, Masayasu Ohtani1970 Volume 34 Issue 8 Pages 814-820
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe reduction of plate specimens of Cu2O and NiO with H2 and CO has been studied over the temperature range of 200°∼1000°C. The reduction process was observed by a high temperature microscope, and the pore structure of the reduced metal was also observed by a scanning electron microscope. The results obtained are summarized as follows:
(1) At the initial stage of the reduction of Cu2O, the incubation period was observed below 300°C. In the low temperature range, the chemical reaction is the rate determining step, and the activation energy of the reaction being 14±2, and 29±2 kcal/mol in the reduction with H2 and CO respectively. With rising temperature, the effect of pore diffusion appears gradually with its increasing contribution to the rate determining step.
(2) The shape and size of pores in the reduced metals are strongly influenced by the mechanism of the formation of the metallic phase which depends on temperature. Sintering may not be considered as an effective factor for the pore distribution except in a high temperature range near the melting point.
(3) In the reduction with H2, many nuclei of metallic Cu appear on the surface, then grow almost uniformly and the reduction proceeds topochemically. On the contrary, in the reduction with CO, a few nuclei appear locally and grow over the surface and the reduction was not observed topochemically in macroscopic structure.
(4) The reduction processes of NiO with H2 and CO are quite different each other. In the reduction with H2, the incubation period was not observed. Below 400°C, the chemical reaction is considered as the rate determining step and 12±1 kcal/mol is obtained as the activation energy.
In a high temperature range, pore diffusion is an important factor in the determination of the rate determining step. The plate specimen of NiO is hardly reduced by CO below 600°C because of the formation of the protective Ni3C layer. At a higher temperature, the protecting effect of Ni3C becomes weak and reduction is able to proceed steadily, but the rate of the reduction with CO is much smaller than that of H2 reducion.View full abstractDownload PDF (3088K) -
Hidehiko Yoshida, Shin Takeuchi, Yasumitsu Fukuzawa1970 Volume 34 Issue 8 Pages 821-825
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWire specimens of nickel solid solutions were strained in tension at various temperatures between liquid helium and 500°K to investigate the effect of solute atoms on the mechanical properties of nickel. The solute elements added were Al, Cr, Si, Sb and Ti; they have wide solubility limits in nickel, and their atomic sizes are largely different each other.
Main results obtained are as follows: (1) The temperature dependence of yield stress became more pronounced with increasing solute concentration, as generally observed in FCC alloys. At the high temperature, however, the yield stress still continued decreasing up to 500°K. This behavior is different from the ordinary FCC alloys. (2) The hardening effect of the solute elements was the highest in Sb atom and increased in the order of Al, Cr, Si, Ti and Sb. Some correlation was found between the hardening effect and the atomic size of solute element. (3) The yield stress at 0°K obtained by extrapolation of the σy−T curve was related to the solute concentration by the equation σy∝cn, where n was a constant between 2/3 and 1 in each alloy system and became larger in the harder alloy. (4) Activation volumes were determined by the strain rate change method. They turned out to be an order of magnitude larger than the value that is expected when the rate determining process is the interaction between the dislocation and each solute atom. (5) The results (3) and (4) cannot be explained by the existing theories on solid solution hardening.View full abstractDownload PDF (1682K) -
Toshinari Hirayama, Masahiko Ogirima1970 Volume 34 Issue 8 Pages 826-829
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate the influence of working temperature on the martensitic transformation which is closely related to the mechanical properties, the Fe-Cr-Ni stainless steel sheets containing 16.5∼19%Cr and 7∼11.5%Ni were rolled at several temperatures between room temperature and 200°C, and the saturation flux densities of these specimens were measured to estimate the amount of martensite. Furthermore, the relations among chemical composition, working temperature and amount of generated martensite was considered thermodynamically.
The results obtained are summarized as follows. The stainless steel, which has a chemical composition in which the austenite is unstable at nomal temperature, generates more strain-induced martensite with lowering working temperature. In this respect, the rise in working temperature by 10°C is equivalent thermodynamically to the increase in the Ni equivalent by 0.3%. This deduction coincides with experimental results.View full abstractDownload PDF (1272K) -
Toshinari Hirayama, Masahiko Ogirima1970 Volume 34 Issue 8 Pages 830-835
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate the influence of working temperature on the mechanical properties of Fe-Cr-Ni stainless steel, the specimens were rolled at several temperatures between room temperature and 200°C. These specimens had such chemical compositions as to make the austenite structures stable or unstable at room temperature. Then, the amount of martensite formed in specimens were estimated by means of saturation flux density measurement, and the Federbiegegrenze, Young’s modulus, tensile strength, and elongation were also measured. The results obtained are as follows:
(1) The variation in the mechanical properties with working temperature was considerably large in the specimens with chemical compositions in which the austenite structures were unstable at room temperature: Namely, the strength became greatly lowered according to a sharp decrease in the amount of strain-induced martensite with the rising working temperature.
(2) A good elongation and a relatively high strength were obtained by warm working of specimens with a chemical compositions in which the austenite structures were very unstable at room temperature.
(3) There was a little influence of working temperature on mechanical properties of the specimens with chemical compositions in which the austenite structures were stable at room temperature.
(4) The relationships were shown between the mechanical properties and the modified Ni equivalent, which is a universal quantity deduced thermodynamically from the chemical composition and the working temperature.View full abstractDownload PDF (1802K) -
Yoshiaki Tanaka, Ky\={o}ji Tachikawa, Kazusada Sumiyama1970 Volume 34 Issue 8 Pages 835-842
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA compound richer in Ga, VGa2, was formed on the surface of V tapes dipped into a molten Ga bath. By heat treatment at 700°C the VGa2 was changed to V3Ga2 and then V3Ga was formed by diffusion between the V3Ga2 and the V substrate. Effects of Cu additions to the Ga bath and Cu plating before the heat treatment on the diffusion process were studied using optical metallography and electron probe microanalysis. Superconducting transition temperatures of the tapes were also measured.
Without Cu addition, diffusion between V3Ga2 and V proceeds through grain boundaries. By the Cu addition, the diffusion mode changes to bulk diffusion and formation rate of the V3Ga is increased by one order of magnitude. By the Cu plating before the heat treatment the diffusion is also much enhanced. The plated Cu layer rapidly absorbs Ga from the VGa2 and V3Ga2 compounds and Cu diffuses into the compounds. The main reason for the enhancement of the diffusion seems to be the lowering of melting points of VGa2 and V3Ga2 by the Cu addition. The Cu does not penetrate into the V3Ga and makes the formation of V3Ga much easier without deteriorations of the intrinsic superconducting properties.View full abstractDownload PDF (3440K) -
Hideo Tai, Shigenori Hori1970 Volume 34 Issue 8 Pages 843-846
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEquilibrium phase diagrams for the CdTe-Sb and CdTe-Bi systems have been determined by means of differential thermal analysis, X-ray diffraction and microscopic examination. The results are as follows:
(1) CdTe-Sb system: This system can be considered as a pseudobinary system from the result of X-ray experiment. There is no intermediate phase except CdTe and Sb phases in any composition. Mutual solid solubility of CdTe and Sb could not be detected by X-ray analysis. The monotectic temperature lies at 1049.5°C and the region of the liquid immissibility at this temperature is given as the composition of 18±2∼58±2 mol%Sb. The eutectic point lies at 98.8 mol%Sb and 623°C.
(2) CdTe-Bi system: This system can also be considered as a pseudo-binary system from the result of X-ray experiment. Mutual solid solubility of CdTe and Bi could not be detected and there is no intermediate phase in this system. The existence of the monotectic reaction in this system is estimated and the monotectic temperature and the region of the liquid immissibility at this temperature are 1061°C and 10±2∼39±5 mol%Bi respectively. The eutectic point lies at 99.992 mol%Bi and 270.5°C.View full abstractDownload PDF (1264K) -
Hakaru Masumoto, Shôhachi Sawaya, Michio Kikuchi1970 Volume 34 Issue 8 Pages 847-850
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe thermal expansion at −150°∼900°C and Young’s modulus at −150°∼700°C and the rigidity modulus at room temperature of Fe-Cr alloys containing 0∼59.10%Cr have been measured, and it has been found that the mean linear coefficient of thermal expansion at 0°∼40°C has minimum values of 9.94×10−6 and 10.60×10−6 in the annealed alloys containing 19.90% and 54.10%Cr, respectively, showing a weak Invar property. In the composition range of about Fe-17∼39%Cr alloys show the Elinvar property at relatively low temperatures, and the highest transition temperature of 230°C is found in the alloy containing nearly 25%Cr. The negative minimum value of the temperature coefficient of Young’s modulus at 0°∼40°C is −6.81×10−5 in the alloy containing 19.43%Cr. A negative minimum value of −9.60×10−5 in the temperature coefficient of Young’s modulus at 0°∼40°C is also obtained with Fe-54.10%Cr alloy, indicating the Invar property.View full abstractDownload PDF (692K) -
Hakaru Masumoto, Michio Kikuchi1970 Volume 34 Issue 8 Pages 850-855
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSRod-form single crystals of Fe-19.43%Cr alloy 3 mm in diameter and 12 cm in length were prepared, and measurements of the thermal expansion and Young’s modulus in the temperature range −150° to 250°C and the rigidity modulus at 20°C were carried out by means of dilatometer, a vibrator-controlled oscillator system and the torsion pendulum method, respectively. The data calculated from these measured values, showed that the Young’s moduli at 20°C were 14.22×105, 22.23×105 and 27.37×105 kg/cm2, and the rigidity moduli at 20°C were 11.36×105, 7.21×105 and 6.43×105 kg/cm2 in the ⟨100⟩, ⟨110⟩ and ⟨111⟩ directions of the single crystals, respectively, the elastic anisotropy being not so large. The Young’s modulus in the ⟨111⟩ direction exhibited a small minimum at 10°C and a small maximum at about 110°C with increasing temperature, while the Young’s moduli in the ⟨100⟩ and ⟨110⟩ directions decreased monotonously. The mean temperature coefficients of Young’s modulus at 10°∼110°C were −32.77×10−5, −9.85×10−5 and +4.71×10−5 in the ⟨100⟩, ⟨110⟩ and ⟨111⟩ directions, respectively. The calculated value of Young’s modulus for a polycrystal agreed fairly well with the measured one for the polycrystal specimen prepared by melting.View full abstractDownload PDF (1388K) -
Tsuyoshi Inoue, Shushi Kinoshita, Akira Suzuki1970 Volume 34 Issue 8 Pages 855-860
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCarbides formed in the isothermally transformed molybdenum steels have been studied in the temperature range 675°∼550°C. Two kinds of carbides, M3C and M23C6, appeared depending on chemical composition (Mo/C ratio) and/or isothermal transformation temperature. In steels with Mo/C ratios less than 1.0, M3C carbide precipitates over the temperature range 675°∼550°C, while in steel with the Mo/C ratio equal to 1.0 M23C6 carbide is formed at or above 650°C and M3C carbide at or below 625°C.
The orientation relationships between M23C6 carbide and ferrite have been determined using transmission electron microscopy and the electron diffraction technique. Several sets of orientation relationships instead of one characteristic relationship are observed, suggesting that M23C6 carbide and ferrite are formed separately in austenite.View full abstractDownload PDF (1677K) -
Shushi Kinoshita, Takeshi Ueda, Akira Suzuki1970 Volume 34 Issue 8 Pages 861-866
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe amount and size of aluminum nitride present at austenitic grain coarsening temperatures have been investigated using nine kinds of 0.2%C low alloy steels. Following the solution treatment of aluminum nitride at 1200°C and quenching, austenitic grain coarsening temperatures have been measured by 5 hr heating at various austenitizing temperatures. The amount of aluminum nitride at the temperatures has been determined by the bromine-ester method, and then electron microscopic measurement of the particle size has been carried out. It has been shown that aluminum nitride of 60∼100 ppm in amount and 10−15 cm3 in size is required to prevent austenitic grain coarsening after the particular heat treatment.View full abstractDownload PDF (2943K) -
Yoichi Ito1970 Volume 34 Issue 8 Pages 866-870
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe behavior of plastic anisotropy of magnesium sheet, and the relation between R value and earing of magnesium sheet were examined at elevated temperatures. The results are as follows.
(1) R values increase as non-basal slip becomes active. Therefore, they increase with the angle between the tensile axis and the rolling direction, the tensile elongation, and the testing temperature.
(2) Eearing occurs in the rolling direction, where R value is minimum. This result is explained from the relation between the parameters specifying the state of anisotropy and earing.
(3) No correlation is observed between ear height and R coefficient, (Rmax−Rmin)⁄Raverage, i.e. the latter decreases as the testing temperature is increased, but the former does not change.View full abstractDownload PDF (1630K) -
Mitsuo Asawa1970 Volume 34 Issue 8 Pages 871-877
Published: 1970
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESS18-8 austenitic stainless steel in the form of U-bends was exposed to sulfuric acid containing sodium chloride and sodium sulfate to observe the effects of hydrogen ions, sulfate ions and chloride ions on the types of corrosion of this steel at temperatures between 25° and 65°C.
2 N and 5 N sulfuric acids containing 0∼0.1 N sodium chloride produce general corrosion, those containing 0.1∼0.2 N sodium chloride produce intergranular corrosion in the deformed part of the steel, the solutions containing 0.4∼0.6 N sodium chloride produce transgranular stress corrosion cracking, and 0.8∼1 N sodium chloride in the sulfuric acids restrain corrosion and cracking of the steel. And sulfate ions are prone to hider the solutions from generating corrosion and stress corrosion cracking. Quasi-martensite caused by deformation of the steel increases the rate of general corrosion.
Generally in the strong acid solutions the corrosion rate of 18-8 austenitic stainless steel is decreased by the adsorption of chloride ions on the metal surface, and stress corrosion cracking is produced when dissolution accelated by the interaction between the strain of the metal and chloride ions is localized by the adsorption of chloride ions and sulfate ions.View full abstractDownload PDF (3353K)
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