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Volume 42, Issue 10
Displaying 1-16 of 16 articles from this issue
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Michio Iseki, Hiroyuki Kubota, Tomoo Kirihara1978 Volume 42 Issue 10 Pages 925-930
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe absorption spectra of pure silver chloride from molten to solid state were measured in the range of wave-lengths from 400 to 800 nm at temperatures between room temperature and 600°C.
The observed spectra of silver chloride exhibited a large absorption band edges based on indirect transition from the L3′ to the Γ1 energy state at about 450 nm and broad peaks at 510 nm and about 650 nm. These peaks are affected by the conditions of measurements and temperatures. The wavelength of maximum absorption in the region of 600∼670 nm is shifted to longer wavelength with increasing temperature of the solid and melt. With this shift, the intensity of maximum absorption increases and the band edge shifts to a longer wavelength. The 510 nm band continues to grow with the exposure time to ultraviolet irradiation.
These bands are interpreted by assuming some defects in AgCl.
The results obtained are as follows:
(1) The 510 nm band corresponds to a well-known silver colloid band (Ag0) in solid.
(2) The 600∼670 nm band in solid silver chloride corresponds to that of the 680∼690 nm band in liquid. This band is thought to be due to the F or F-like center which is an anion vacancy trapping an electron.View full abstractDownload PDF (524K) -
Tetsuro Ishizaki, Takeshi Ono1978 Volume 42 Issue 10 Pages 931-936
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe compositions of ferrite and austenite in two-phase stainless steels have been studied by an electron probe microanalyser. The relation between the amount of ferrite and the Ni and Cr equivalents of sample composition coincided with Schaeffler’s diagram. The Cr and Mo contents in ferrite decreased and the Ni content in ferrite increased with increasing solution temperature. The Cr content increased and the Mo content decreased with increasing Cr composition of sample. The Ni, Cr and Mo contents in austenite did not change with increasing solution temperature. In the austenite phase, increasing the amount of frrite or the Cr composition of sample resulted in an increase in the N content. The structural diagram of the Fe-Ni-Cr system is presented relating in terms of the Ni and Cr equivalents of the ferrite and austenite phases.View full abstractDownload PDF (421K) -
Mizuo Edamura, Minoru Makimura, Takashi Kajikawa, K\={o}ichi Imai, Sat ...1978 Volume 42 Issue 10 Pages 936-941
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIon-softnitriding is one of the method of surface-hardening which uses a few percent of hydrocarbon gas (i.e. propane gas) with nitrogen-haydrogen mixing gas as another ionic bombarding element.
The tentative standard condition of ion-softnitriding was initially determined, and then the effects of gas composition, total gas pressure, current density and voltage on the metallurgical properties of the nitrided layers in S15C, S48C, SCM3, and SACM1 steels were investigated by means of optical microscopy and X-ray analysis. The obtained results were compared with those for the ordinary ion-nitriding. The main results were as follows.
(1) When the C3H8 gas content in the mixing gas was increased, the amount of the ε-Fe2-3N phase in the compound layer was increased. When the C3H8 gas increased more than 1 vol.%, the Fe3C phase was formed.
(2) The thickest compound layer was obtained when the concentration of N2 gas was around 50 vol.%, and a similar tendency was observed at the C3H8 gas concentration up to 1 vol.%.
(3) When the total gas pressure was increased, the voltage and the thickness of the compound layer were decreased.
(4) When the current density was increased, the voltage and the thickness of the compound layer were increased.
(5) The depth of the diffusion zone was hardly affected by such conditions as gas composition, total gas pressure, current density, and voltage, when the nitriding temperature and time were constant.View full abstractDownload PDF (581K) -
Mizuo Edamura, Minoru Makimura, Takashi Kajikawa, K\={o}ichi Imai, Sat ...1978 Volume 42 Issue 10 Pages 942-946
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe volume ratio of ε-Fe2-3N phase to the sum of ε-Fe2-3N and γ′-Fe4N phases in the compound layers in ion-nitrided and ion-softnitrided S15C, S48C, SCM3, and SACM1 steels were measured using the X-ray diffraction pattern. The microstructures of ε-Fe2-3N, γ′-Fe4N and Fe3C phases were observed by transmission electron microscopy and electron diffraction. The main results were as follows.
(1) The ratio of cε⁄(cε+cγ′) for ion-nitrided SACM1 steel was relatively large (about 0.4∼0.7), but those for ion-nitrided SCM3, S48C, and S15C steels were less than 0.4, 0.25, and 0.15 respectively. Here cε and cγ′ were the volume fractions of ε-Fe2-3N phase and γ′-Fe4N phase in the compound layer.
(2) The ratio of cε⁄(cε+cγ′) for ion-softnitrided steels were larger than those for ion-nitrided steels.
(3) When the nitriding temperature raised, the ratio of cε⁄(cε+cγ′) was increased.
(4) The hardness of the surface in ion-nitrided and ion-soft-nitrided steels generally increased with increase in the value of cε⁄(cε+cγ′).
(5) The shape and amount of ε-Fe2-3N, γ′-Fe4N and Fe3C phases in the compound layers were observed by transmission electron microscopy. Each phase was detected by the electron diffraction pattern.View full abstractDownload PDF (535K) -
Mutsuo Ohta, Masuo Yamada, Teruto Kanadani, Moritaka Hida, Akira Sakak ...1978 Volume 42 Issue 10 Pages 946-954
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAl-10 wt%Zn alloy was studied by measurements of electrical resistivity and X-ray small-angle scattering intensity and by transmission electron microscopy. Specimens were quenched from mainly 300°C (TQ1) into lower quenching temperature (TQ2, 110∼230°C), maintained for various lengths of time at TQ2, quenched into ice-water and aged isothermally at 0° or 40°C. Results obtained are: (1) When the specimen was maintained at TQ2 for a length of sufficient time and aged at relatively high temperature (e.g. 1 h at 125°C and aged at 40°C), a two-step increment of both resistivity and integrated intensity was recognized. (2) Each of the steps has the characteristics of the formation of G.P.zones by the spinodal decomposition. (3) The maximum resistivity (ρmax) changes with the maintenance period at TQ2. It decreases at the beginning, then rises gradually through the minimum, and finally attains a constant value. (4) When ρmax takes a minimum, the width of the size distribution of the G.P.zones estimated from the difference between the Guinier and Porod radii is considerably large compared with that at ρmax in the usual case of direct quenching. (5) When the period at TQ2 is longer enough, the width at ρmax is similar to that at the same step of the usual treatment. (6) After a prolonged ageing under the condition to make ρmax minimum, G.P.zones grow markedly and become oblate ellipsoids with a major axis of about 20 nm. (7) These results are consistently understood in terms of the fluctuation of solute concentration at TQ2 and the changes in the concentration of vacancies during annealing at TQ2. That is, it is considered that these results are due to the difference in ageing behaviour between the relatively concentrated region and the relatively dilute region induced by fluctuation.View full abstractDownload PDF (1304K) -
Mutsuo Ohta, Teruto Kanadani, Akira Sakakibara, Masuo Yamada1978 Volume 42 Issue 10 Pages 954-960
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAl-2.0 wt%Zn and Al-4.0 wt%Zn alloys were studied by measurements of electrical resistivity and intensity of X-ray small-angle scattering. The results obtained are: (1) There are two stages in the isochronal annealing curves when the alloys are aged at low temperature after quenching from 400°C. The amount of the change in resistivity in the second stage increases as the aging time increases, while that in the first stage decreases. (2) The second-stage reversion starts at least 10°C higher than the finishing temperature of the first stage. (3) The X-ray S.A.S. intensity from the zones reverted at the first stage can not be represented by Porod’s approximation, while that at the second stage can be approximated. (4) G.P.zones formed by the nucleation-and-growth mechanism were recognized when Al-2.0 wt%Zn alloy was aged at 0°C and Al-4.0 wt%Zn alloy at 40°C. These zones are reverted nearly in the same temperature range as the range of reversion of G.P.zones formed in the low-temperature aging from which the X-ray intensity curves can be represented by Porod’s approximation.View full abstractDownload PDF (585K) -
Hakaru Masumoto, Naoji Nakamura, Yuetsu Murakami1978 Volume 42 Issue 10 Pages 960-966
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMagnetic properties, thermal expansion coefficient, electrical resistivity and hardness have been studied for Fe-Nb-Co alloys containing less than about 4%Nb and less than 25%Co or Fe-Ta-Co alloy scontaining less than about 8%Ta and less than 30%Co. All alloys used in this study were water quenched from 1050°C, cold drawn by 97.2% reduction in area and subsequently reheated at 400∼1000°C for less than 5 h. The magnetic properties for Fe-Nb-Co and Fe-Ta-Co alloys depend remarkably on the cobalt concentration, reheating temperature and reheating time. With increasing Co content of these alloys in both systems, the thermal expansion coefficient decreases monotonously, the hardness increases monotonously, and the electrical resistivity shows a maximum at the composition of 15%Co content. The magnetic properties of Recalloys, which were water quenched, cold drawn and subsequently reheated at 700°C for 30 min, exhibit very superior values as follows. For Fe-about 3%Nb-20%Co alloy: B8(at 8 kA·m−1)=1.95 T, Br=1.80 T, Br⁄B8=0.923, Hc=1.10 kA·m−1 and \sqrt(BH)max⁄BrHc=0.935; for Fe-about 3%Ta-20%Co alloy: B8=2.10 T, Br=1.95 T, Br⁄B8=0.924, Hc=1.29 kA·m−1 and \sqrt(BH)max⁄BrHc=0.907. α at 0∼40°C, ρ and Hv in the above alloys are 110×10−7, 0.206 μΩ·m and 345 or 115×10−7, 0.169 μΩ·m and 381, respectively.View full abstractDownload PDF (547K) -
Junichi Kaneko, Makoto Sugamata, Ken-ichiro Aoki1978 Volume 42 Issue 10 Pages 966-972
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIsothermal holding of an Al-19 wt%Si alloy containing 0.02%P has been carried out at 620°C to determine the rate of Ostwald ripening of primary Si crystals in Al melt. It is shown that the average radius of these crystals during isothermal holding can be expressed by an equation; R3−R03=kt, where a constant k is determined to be 1.6×10−12 cm3/s. When the specimens are solidified at a constant cooling rate of ΔT⁄Δt, both solidification growth and Ostwald ripening take place simultaneously. This can be approximated as repetitions of quenching from Tn to Tn−ΔT followed by isothermal holding for the period Δt. The change of the average radius of primary Si crystals during solidification at constant cooling rate has been numerically analyzed by separating Ostwald ripening during isothermal holding from solidification growth during quenching. It is shown that contribution of Ostwald ripening increases with decreasing cooling rate and/or with increasing number of primary Si crystals formed at the onset of solidification. The number of primary Si crystals after complete solidification is primarily dependent on their number at the onset of solidification, and the effect of Ostwald ripening is of minor importance. These results obtained on primary Si crystals are also discussed in comparison with those on primary dendrites.View full abstractDownload PDF (713K) -
Hiroaki Kurishita, Sadakichi Kitajima1978 Volume 42 Issue 10 Pages 973-980
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA refined technique for etch-pitting in copper crystals has been developed in order to distinguish between different kinds of dislocations and to produce stainless, well-defined etch-pits in multiple etching. The technique has been applied to study the configurations of grown-in dislocations emerging on a {111} crystal surface of well-annealed copper crystals. The results obtained are as follows.
(1) Two etchants (modified Young’s etchant), [A] (FeCl3·6H2O:28 g, HBr:2.1 cm3, HCl:120 cm3 and H2O:80 cm3) at the working temperature 281.5 K and [B] (FeCl3·6H2O:43 g, HBr:4.3 cm3, HCl:100 cm3 and H2O:100 cm3) at the working temperature 293 K, are found most suitable for distinction between edge and screw dislocations and between opposite edge dislocations, respectively. (2) Multiple etching can be successfully performed by the use of intermediate etching in a solution of chromic acid and HCl. (3) Grown-in dislocations both in edge orientation and in near-screw orientation frequently have large super-jogs as high as 40∼60 μm. (4) Grown-in dislocations in a surface layer within a depth of 20 μm are perpendicular to the trace of the slip plane on the surface, but in the interior beyond that depth they are often bent on individual slip planes. (5) Threefold nodes occasionally exist very close to the as-annealed surface. (6) Edge dislocation dipoles have been observed on the as-annealed surface. (7) Ratio of grown-in dislocations in 30°-screw orientation to those in edge orientation is about 2 in crystals with a dislocation density higher than 5×103/cm2, but it decreases to about 0.7 in crystals with a dislocation density of 5×102/cm2.View full abstractDownload PDF (2074K) -
Hisaaki Fukushima, Tetsuya Akiyama, Susumu Akagi, Kei Higashi1978 Volume 42 Issue 10 Pages 980-985
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBinary and ternary alloys of molybdenum with iron-group metals were electrodeposited on the copper cathode from baths containing molybdic acid, iron-group metal (II) sulfate, potassium sodium tartrate (as a complexing agent) and ammonium hydroxide (for adjusting pH of the solution 10.5) under galvanostatic conditions, and the relationships between the composition of electrodeposited alloys and the cathode current efficiency were studied. With increasing molybdenum content of the alloys, the partial current efficiency of molybdenum tended to increase first and then decrease to nearly zero after a maximum was achieved. This showed the existence of two characteristic alloy compositions, i.e., the content of molybdenum at a maximum partial current efficiency of molybdenum and the one at the upper limit of molybdenum deposition. These characteristic composition were in good agreement with the calculated ones based on the number of unpaired 3 d electrons of iron-group metals. Further studies on the electrodeposition of nickel-zinc-molybdenum alloys indicated that electrodeposition of molybdenum ceased when the alloy composition was achieved, in which atomic ratio of zinc to nickel corresponded to the one that the positive holes in 3 d band of nickel were filled up with 4 s electrons of zinc. Thus, unpaired 3 d electrons of freshly deposited iron-group metals appeared to play an important roles in the induced codeposition of molybdenum.View full abstractDownload PDF (490K) -
Kozo Osamura, Masaki Kitagawa, Mahoto Takeda, Yotaro Murakami1978 Volume 42 Issue 10 Pages 986-992
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen a Cu-4.66 wt%Sn-0.86 wt%Mg ternary alloy was aged below 623 K, the precipitates, Cu4SnMg, were uniformly nucleated in the matrix, of which the external form was observed as a regular tetrahedron. Attempts were made to accelerate the reaction of precipitation and to improve the mechanical and electrical properties. When the alloy was pre-aged at 373 a short time after the homogenization treatment and then aged at 573 K, the number of precipitates increased about two times without the change in average size. This means that the increased secondary defects act as the preferential nucleation sites for heterogeneous precipitation. When the alloy was cold-rolled at room temperature and then aged below 623 K, both the number and the size of precipitates increased remarkably. It was found out that their external form is not a tetrahedron but a rhombohedron, and those particles precipitate on the introduced dislocations or their complexes. After the thermo-mechanical treatment (TMT) was applied to the present alloy, a large number of fine particles precipitated uniformly and therefore the mechanical and electrical properties were improved quite well.View full abstractDownload PDF (1051K) -
Nobutoshi Maruyama, Shiro Ban-ya1978 Volume 42 Issue 10 Pages 992-999
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe activities in liquid Fe-Ni, Fe-Co and Ni-Co alloys were determined by a modified transportation method at 1873 K. The activity coefficients of each system can be calculated by a graphical integration of the following equation:
(This article is not displayable. Please see full text pdf.)
\ oindentwhere Ni and Xi are the mole fractions of the component i in the metal and vapor phases, respectively.
In the Fe-Ni system, the activities of iron and nickel were found to be negative deviations from Raoult’s law over the entire composition range and were in good agreement with previous works.
The liquid Fe-Co and Ni-Co solutions approximately show regular solution behavior, and the activity coefficients of the solutions are expressed by the following equations, respectively:
(This article is not displayable. Please see full text pdf.)View full abstractDownload PDF (603K) -
Hirofumi Miyaji, Satoshi Watanabe1978 Volume 42 Issue 10 Pages 999-1007
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo investigate the role of nitrogen on the formation process of {110}⟨001⟩ primary recrystallization texture in 17 Cr stainless steel sheet, the effects of precipitation treatment, cold-rolling reduction and annealing treatment have been studied.
The growing process of {110}⟨001⟩ oriented grains after the end of primary recrystallization is also discussed. The results obtained are as follows:
(1) {110}⟨001⟩ primary recrystallization texture develops remarkably in the following conditions: the hot-rolled sheet, in which nitrogen dissolved supersaturatedly is precipitation-treated at 650°C for 2 h and is cold-rolled by 60% and is annealed with a rapid rate at higher temperature and for a longer time.
(2) Suitably dispersed nitrides suppress the growth of {111}⟨110⟩ and {111}⟨112⟩ oriented grains which have nucleated in the unsystematically deformed region near the grain boundary. As the result, {110}⟨001⟩ oriented grains which have nucleated in the deformed band in the {111}⟨112⟩ deformed matrix grow selectively.
(3) Chromium nitrides have an effect of inhibitor for the development of secondary recrystallization.View full abstractDownload PDF (999K) -
Sumiko Sanuki, Toyoshi Yasukawa, Tosio Izaki1978 Volume 42 Issue 10 Pages 1007-1012
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe solvent extraction of Pb(II) from its perchlorate aqueous solution maintained at constant ionic strength was studied by using Versatic Acid 10 diluted in benzen. The extracted species in the equilibrated organic phase were identified as PbR24RH and PbR22RH, where RH represents the Versatic Acid 10 and R is the carboxylate ion. The apparent equilibrium constants of those extraction were determined to be 8.37×10−8, 6.51×10−8, respectively. The effects of nitrate or chloride ion on the extraction of Pb(II) were also investigated. The extraction of Pb(II) was hindered in the presense of those anions, owing to the complex formation with Pb(II) in the aqueous phase. And the stability constants of Pb(II) complexes with those anions were estimated from the extraction data.View full abstractDownload PDF (441K) -
Hiroshi Yamagata, Osamu Izumi1978 Volume 42 Issue 10 Pages 1012-1019
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDeformation behaviour and ductility of α brass single crystals were examined at elevated temperatures. The experimental results are summarized as follows:
(1) The high temperature yielding and serrated flow observed in single crystals are similar to those of polycrystalline α brass, and those phenomena are considered to be attributed to dynamic strain aging phenomena.
(2) The crystal axis rotation measured over an intermediate temperature range indicate that only the deformation due to the primary slip system proceeds up to the symmetrical line.
(3) Strain rate sensitivity exponent (m-value) increases with increasing temperature, showing a maximum value of about 0.21∼0.24 which is attributed to the viscous motion of dislocations dragging the solute atmosphere around them.
(4) The work hardening rate after a rapid strain rate change at the steady state deformation stage (Δσ-value) takes a maximum at a certain temperature and strain rate.
(5) The ductility of α brass single crystals shows a large temperature dependence. Two ductility maxima (up to about 200% elongation), even in the single crystals, are observed at intermediate and high temperatures, and each of them is correlated to the increased Δσ and m-values, respectively.View full abstractDownload PDF (726K) -
Seiichi Iwata, Akitoshi Ishizaka1978 Volume 42 Issue 10 Pages 1020-1021
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (132K)
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