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Volume 45, Issue 1
Displaying 1-17 of 17 articles from this issue
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Masanobu Kobayashi, Kunio Ito1981 Volume 45 Issue 1 Pages 1-4
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe measured anisotropy of damping capacity has been compared with the one calculated using a model of static hysteresis damping. The results show that not simple but rather complex mechanisms are responsible for the damping capacity of this alloy.
Test pieces 1.7 mm in width and 110 mm in length were cut from a 80% cold-rolled sheet 0.5 mm in thickness with the angle α to the rolling direction, and quenched from 750°C. Their specific damping capacity (SDC) has been measured at −30∼+30°C by a torsional pendulum method (∼0.25 Hz) in the course of ageing at 400°C.
In the range of applied shear strains 3×10−5∼12×10−5, SDC increases approximately linearly with increasing strain amplitude. The strain independent SDC, which was obtained by a linear extrapolation of SDC to strain amplitude ε=0, is independent of the angle α, while the strain dependent SDC, which was deduced from the whole SDC by subtracting the strain independent one, shows some dependence on the angle α.
The dependence of the damping capacity on the angle α has been calculated on the assumption that SDC is proportional to the volume swept by twin boundaries in compliance with the strain induced re-orientation of their tetragonal lattice distortion. Preferred orientations in the sheet necessary for this calculation are estimated from the pole figure data and the observed anisotropy of rigidity modulus. The observed anisotropy of the strain dependent SDC has been revealed to be affected by the ageing condition and to be always smaller than the calculated one.
The damping capacity of this alloy should be therefore interpreted as consisting of three components, i.e. the component independent of both strain and crystal orientation, the component dependent on strain but not on crystal orientation, and the component dependent on the two.
The contribution of each of these three components is expressed as a function of ageing time and damping measurement temperature, and the corresponding mechanism is discussed.View full abstractDownload PDF (322K) -
Hideo Suda, Tohru Watanabe, Yoshinari Misaki, Yoshimi Tanabe1981 Volume 45 Issue 1 Pages 5-12
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe structure of the deposited alloy film by the electroless plating method changes continuously from crystalline, which is the aggregation of very fine crystals, to amorphous with increasing boron or phosphorous contents in the deposited film. In this investigation, the deposit condition to make the amorphous alloy in the electroless plating bath using dimethylamine borane (DMAB) as a reducing agent was studied. The increase of reducing agent concentration in the plating bath increases the boron content in the deposited film and contributed to make an amorphous film. Furthermore, the decrease of pH and the increase of temperature of the plating bath also had the same effect. The added other agent for reduction of internal stress in the deposited film and to stabilize the pH of the plating bath did not show any pronounced effect on the concentration of boron in the deposited film. Finally, the Ni-B alloy film prepared in this investigation contained a maximum amount of 16.2 at%B and showed an amorphous-like structure with a small amount of fine nickel crystals.View full abstractDownload PDF (955K) -
Kunio Nagaoka, Toyojiro Isano, Yasunori Kawai1981 Volume 45 Issue 1 Pages 13-19
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAnodic polarization behaviors at the local region near a grain boundary groove of Al-Zn-Mg alloys in 3%NaCl aqueous solution containing K2Cr2O7, and the relation between stress-corrosion (SC) and hydrogen were discussed. The break-down potential was shifted to the noble side by soluble oxygen in the electrolyte, and the potential in the grain boundary groove became more noble than that on the grain, and the break-down potential was shifted to the less noble side by the applied stress. Anodic polarization in the grain boundary perpendicular to the applied stress deteriorated in reproducibility with increasing stress. The tensile strength of the specimens subjected to the SC treatment (147.1 MPa, 3.6 ks, 3%NaCl+5 kg/m3 K2Cr2O7 at 323 K) were measured as tensile strength at intervals of 0 s, 86.4 ks, 172.8 ks and 1.728 Ms. The tensile strength decreased up to 172.8 ks, but gradually recovered to the previous strength at 1.728 Ms. Thus, this will be inferred from absorption, diffusion and release of hydrogen gas in the specimen. Tensile fracture surfaces are observed by scanning electron microscopy. Specimens which were not treated with SC generated chemically reactive micro-cracks at the intergranular, but in the SC treatment, cracks initiated at the edges of three adjacent grains, and the former fracture surface showed intergranular cracking, but the latter showed a both intergranular cracking and transgranular cracking.View full abstractDownload PDF (823K) -
Yuji Sadakane, Tetsuo Abe, Ken-ichi Hirano1981 Volume 45 Issue 1 Pages 20-28
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe diffusion behavior of the terrace-adatoms on the (431) and (321) planes and the ledge-adatoms on the (211) and (321) planes of tungsten in the temperature range between 270 and 350 K has been studied using a field-ion microscope and a newly developed theoretical treatment of the probability density of adatom displacement. It has been found that edge of the terrace acts as a trapping boundary for the diffusing terrace-adatoms on the (431) and (321) planes below about 300 K. Diffusion of the ledge-adatoms on the (211) and (321) planes resembles that of the terrace-adatom on the (321) plane.View full abstractDownload PDF (881K) -
Hideto Koga, Yasuo Uchiyama, Hiroaki Inokuchi, Osamu Koge1981 Volume 45 Issue 1 Pages 29-34
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of Si concentration on the reaction between iron and zinc was studied to obtain information about the Si effect on this reaction. Eight Fe-Zn alloys with different Si concentration were immersed into pure molten zinc for 600 s at 733, 773 and 873 K. Iron loss and the alloy layer thickness were measured and the alloy layer structure was examined. The results are as follows:
(1) δ1 was formed next to Γ under all experimental conditions, and its thickness did not depend on the Si concentration except a few conditions.
(2) At 733 K, ζ was formed next to δ1 up to 0.25%Si, while above this Si concentration (δ1+η) mixture was formed next to δ1, followed by ζ. ζ formed on 0.10%Si alloy was an aggregate of small crystals.
(3) (δ1+η) was formed at 733 and 773 K, and grew faster in the Si concentration range of 1.0∼1.15%Si.
(4) The reaction between iron and zinc proceeded rapidly in the region of 0.1%Si at 733 K, as Sandelin reported, and also in the range of 1.0∼1.15%Si at 733 K and 773 K.
(5) The reaction at 873 K did not depend on the Si concentration.View full abstractDownload PDF (674K) -
Shinji Takayama, Mitsuhiro Kudo1981 Volume 45 Issue 1 Pages 34-39
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCalorimetric thermograms of amorphous alloys were obtained with a differential scanning calorimeter under high sensitivity. With this method, the structure relaxation of amorphous alloys can be easily detected as an apparent broad exotherm spectrum at a relatively low temperature far below the crystalization temperature.
The structure relaxation of Fe-based (i.e., Fe80B20, Fe80P20, Fe40Ni40B20, Fe40Ni40P14B6) or Ni-based (Ni80P20, Ni80P10B10) amorphous alloys takes place over wide temperature range, from relatively low temperature (373∼423 K) to crystallization temperature. The temperature at which the exotherm reaction starts to occur due to the structure relaxation in an amorphous structure, Tn, and the total amount of exothermal heat due to the structure relaxation vary with both alloy composition and heat treatment. It was suggested that the embrittlement at low temperatures are (likely to be) related to the structure relaxation in the amorphous structure.View full abstractDownload PDF (753K) -
Tokuzou Tsujimoto1981 Volume 45 Issue 1 Pages 40-49
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSExpanding composition variations in supersaturated solid solutions of a symmetric alloy into Fourier series whose component of wavenumber hβ is denoted by Q(h), we obtain as diffusion equation
(This article is not displayable. Please see full text pdf.)
\ oindentD0⁄D2=−0.0676 for equilibrium compositions of 0.50±0.45 and K is (gradient energy coefficient)×(mobility of atoms). S(h) is a function which is obtained by convoluting Q(h) twice. Calculation using this equation depicts all the process of one-dimensional structure change with aging: decomposition by amplification in amplitude of composition variations and aggregation of precipitates, and generation of modulated structure and improvement of the periodicity with aging. The second term acts effectively in a large amplitude of composition variations, and this term gives multiplication of Fourier waves, along with such functions as self-control for amplification of Fourier waves, interference against amplification of other waves, and linkage with other waves.
Composition variations amplifies by virtue of the first term and stops amplifying at the equilibrium composition by virtue of the self-control and the interference effect. The interference gives rise to competition among the Fourier waves. Under the action of the linkage effect at a later stage of aging, the competition progresses through repetition of formation of a pseudo-equilibrium Fourier spectrum and its destruction. Spectra shift to low frequency side by this process, which corresponds to the aggregation process of precipitates. Modulated structure of diffuse periodicity is produced by the action of the first term and the periodicity is improved by the interference and the linkage effect.View full abstractDownload PDF (863K) -
Jirô Watanabé1981 Volume 45 Issue 1 Pages 49-54
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn apparatus for producing an image of light figure on a television has been designed and applied for the orientation determination of metal crystals. The apparatus consists of two main parts: one is a light-figure microscope which is provided with an optical system for producing the optical image of light figure and a goniometric mechanism for measuring the orientation angles by the light figure, and the other a television system which converts the optical image into the electrical signal and displays the light figure on television. Full accounts are given of the construction of the apparatus and the procedure and accuracy of the orientation determination with some actual examples. It is shown that a clear-cut light figure can be observed on a television by adjusting properly its contrast and brightness. The orientation work can be conducted without a dark room. The accuracy of the determination of crystal orientations is well within 0.017 rad (1°).View full abstractDownload PDF (727K) -
Fumio Kurosawa, Isamu Taguchi, Ryutaro Matsumoto1981 Volume 45 Issue 1 Pages 55-63
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe sigma phase in austenitic stainless steels has been studied using the non-aqueous electrolyte-potentiostatic etching method (the SPEED method) and the potentiostatic isolation method.
The results obtained are summarized as follows.
(1) Three-dimensional observation of sigma phase on grain boundaries in austenitic stainless steel are successfully conducted by the SPEED method.
(2) Sigma phase, carbide (Cr23C6) and nitride (β-Cr2N) are found to be stable when the steel matrix is electrolyzed at +100∼+300 mV vs SCE in 10% acetylacetone-1% tetramethy-lammonium chloride-methyl alcohol electrolyte.
(3) The amounts of carbide (Cr23C6) and nitride (β-Cr2N) are calculated from carbon and nitrogen contents, respectively, which are obtained from the analytical results of the residues isolated by the potentiostatic method.
(4) The amount of the sigma phase is calculated by subtraction of the carbide and nitride amounts from the total amount of the precipitates isolated potentiostatically.
(5) The precipitation behavior of the sigma phase, Cr23C6 and β-Cr2N as a function of the aging time is clear by the above-mentioned analytical data.
(6) Relationship between sigma phase contents determined by the proposed method and the charpy impact values is evident and the sigma phase plays a major role in lowering the toughness.View full abstractDownload PDF (1515K) -
Fumio Kurosawa, Isamu Taguchi, Mitsuru Tanino, Ryutaro Matsumoto1981 Volume 45 Issue 1 Pages 63-71
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNitrides in carbon steels and stainless steels were observed and analyzed using the non-aqueous electrolyte-potentiostatic etching method (the SPEED method).
The results obtained are summarized as follows:
(1) Polarization curves of nitrides were measured by the electric conductive paint method in 10% acetylacetone-1% tetramethylammonium chloride-methyl alcohol electrolyte. Nitrides such as AlN, BN, β-Cr2N, Z-phase and TiN are found to be stable when the steel matrix is etched at potentials lower than +800 mV vs SCE.
(2) In situ observation and analysis of the nitrides, especially film-like nitrides and duplex nitrides in steels were successfully conducted by the SPEED method.
(3) The precipitation behavior and the morphology of the following nitrides were made clear by the SPEED method.
(a) Fine AlN in low carbon steel heat-treated in a high temperature region (1100∼1500 K),
(b) Z-phase in highly purified ferritic stainless steel (19%Cr-2%Mo-0.09%Nb) heat-treated in the temperature range of 650∼1300 K,
(c) Dice-shaped Ti(C,N) in ferritic siainless steel (17%Cr-0.42%Ti).View full abstractDownload PDF (1061K) -
Fumio Kurosawa, Isamu Taguchi, Mitsuru Tanino, Hirowo G. Suzuki, Ryuta ...1981 Volume 45 Issue 1 Pages 72-81
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe precipitates formed at elevated temperatures in carbon steels and stainless steels were observed and analyzed using the non-aqueous electrolyte-potentiostatic etching method (the SPEED method).
The results obtained are summarized as follows:
(1) In situ observation of precipitates and inclusions, such as phosphides and complex inclusions formed at elevated temperatures, were successfully conducted by the SPEED method.
(2) The morphology of complex inclusions in carbon steel samples simulated of continuous casting were made clear; the complex inclusions were mainly composed of MnO, Mn(O, S) and (Mn, Al)O.
MnO containing phosphorus was found as the nucleus in the center of the complex inclusions.
(3) Iron-manganese phosphide was newly observed in high carbon steels. The phosphide was thin film-like and eutectic and was found on fracture surface of the samples strained at high temperatures. The phosphide morphology was changed from a thin film-like into a sphere-like shape during holding time at 1173 K.
From the results obtained by the X-ray diffraction and EDX analysis of the residues isolated from the carbon steels, the phosphide was identified as (Fe, Mn)3P (Tetragonal).
(4) Niobium phosphide was found in SUS 347 (0.018%P).
The thin film-like and eutectic phosphide was found on fracture surface of the continuously cast slab of SUS 347.
The cross-section of structure of the eutectic niobium phosphide was also revealed.View full abstractDownload PDF (1658K) -
Kazuhiro Kumasaka, Kenichi Ono1981 Volume 45 Issue 1 Pages 82-86
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe relation between magnetic anisotropy and magnetic properties was investigated in Fe-12%Co-10%W alloy by measuring X-ray pole figures, magnetic torque curves and magnetic properties. Specimens were aged at 823∼1273 K after cold rolling by 72∼98% reduction ratio in area. The results obtained are summarized as follows.
(1) Residual induction, squareness ratio and coercive force are maximized by aging at 923∼973 K.
(2) Cold rolling texture consists of (100)[011] and (111)[1\bar10]. The (100)[011] component is much stronger than the (111)[1\bar10] component. This texture persists up to 1173 K. The (200) peak intensity in X-ray pole figure increases gradually with rising temperature.
(3) In cold rolling state, magnetocrystalline anisotropy is dominant. The easy magnetizing direction of this magnetocrystalline anisotropy is ⟨100⟩, which is π⁄4 from the rolling direction.
(4) Uniaxial magnetic anisotropy is induced by aging. Aged at 973 K, the easy magnetizing direction of this uniaxial magnetic anisotropy is perpendicular to the rolling direction at 72% reduction ratio in area by cold rolling. However, this easy magnetizing direction becomes parallel to the rolling direction at the more severe reduction ratio in area by cold rolling. Uniaxial magnetic anisotropy constant Ku developes mostly at the aging stage of maximized squareness ratio, and shows Ku=6.8×103 J·m−3 when aged at 973 K after cold rolling of 98% reduction in area.
(5) Ku induced by aging develops gradually with increasing reduction ratio. Developing Ku with increasing reduction ratio accompanies increasing squareness ratio. This indicates that developing unixial magnetic anisotropy with easy magnetizing direction in the rolling direction raises the squareness ratio.View full abstractDownload PDF (363K) -
Akihiko Nagata, Maolin Liu, Osamu Izumi1981 Volume 45 Issue 1 Pages 87-94
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSOverall Jc of in situ Cu-20 mass%Nb-Sn superconducting composites containing 2 and 4 mass% of Ga addition was studied with respect to the dependencies of Sn concentration, heat treatment condition and Ga addition. Microstructures were observed by SEM and EPMA, and the lattice constants of the Cu matrix and Nb3Sn were measured by an X-ray method.
The highest overall Jc of 9×108 A/m2 at 9 T and 4.2 K was obtained after heat treatment at 823 K, which was higher than that of the in situ Cu-22.5 mass%Nb-Sn composites without Ga. Furthermore, the Ga addition increases Tc about 0.3 K after heat treatment at 923 K and lowers the heat treatment temperature for obtaining the high overall Jc. It is considered that the improvement of Jc by the Ga addition is caused by the enhancement in Tc and by the grain refinement of Nb3Sn due to the lower heat treatment temperature.View full abstractDownload PDF (1102K) -
Hisashi Suzuki, Yasuro Taniguchi, Koji Hayashi, Chang Sanuan1981 Volume 45 Issue 1 Pages 95-99
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe reason why the β(WC-TiC solid solution)-free layer (β FL) was formed near the specimen surface was studied mainly for WC-β-TiN-Co alloys containing β and TiN up to 83 and 10%, respectively.
It was found that β FL was formed during vacuum-sintering under a liquid phase. The thickness of β FL was varied depending on the sintering condition and alloy composition, etc. The formation of β FL was related to the escape of nitrogen from specimen surface and was suggested to be rate-controlled by the diffusion of nitrogen through the liquid phase in β FL. The disappearance of the β phase in β FL would be understood, considering the following mechanism. The solute concentration in liquid phase around the β phase increases near the surface because of the lowering of the nitrogen concentration, so that the solutes such as W, Ti and C diffuse into the interior of the specimens.View full abstractDownload PDF (673K) -
Haruno Okochi, Katsuyuki Takahashi, Shunichi Suzuki, Emiko Sudo1981 Volume 45 Issue 1 Pages 100-106
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSUnification of calibration curves for analysing micro-amounts of elements (N,S,C,Mo,Si,Ni,Mn,Cu) in tool steels and high speed steels was investigated. Iron contents in them vary from ca. 65 to 95%, so that classified calibration curves or correction of amounts of iron are necessary in the case of the internal standard method, while satisfied results were obtained by the fixed time integration method.
For correction of interfering elements, iron base binary alloys were used for tool steels and multiple alloys were needed for high speed steels. Further, in order to decide coefficients of correction for high speed steels, the use of multiple regression analysis was investigated, using the calibration curves for only tool steels corrected with binary alloys, high speed steels were determined and the differences between the analytical values and the standared ones were used for calculation. Consequently, coefficients of correction were decided by using binary alloys for tool steels and by multiple regression analysis for high speed steels.
The relation between sensitivities of analysis and coefficients of correction was also examined. As sensitivities the gradients of the calibration curves were chosen, and when the calibration curves were not straight, the gradients of regression lines in the trace region were used. The relation of hyperbola was observed between them; the larger the sensitivities the smaller became the change of coefficients of correction, and the lesser the sensitivities the smaller became the number of interfering elements.
In tool steels, emission intensities were not affected by amounts of carbon from 0.2 to 1.4%, while they decreased in larger amounts of carbon (ca. 1.3%) in high speed steels.
Tool steels and high speed steels were analysed with unified calibration curves. According to the results of the F-test, it was not concluded that there were differences in variance between tool steels and high speed steels and the accuracies of analysis were sufficiently high.View full abstractDownload PDF (487K) -
Hakaru Masumoto, Michio Kikuchi, Takafumi Nakayama1981 Volume 45 Issue 1 Pages 107-108
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (106K) -
Toru Miyazaki, Hiroshi Imamura, Hirotaro Mori1981 Volume 45 Issue 1 Pages 109-110
Published: 1981
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (179K)
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