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Volume 28, Issue 7
Displaying 1-13 of 13 articles from this issue
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Toshimasa Morooka1964 Volume 28 Issue 7 Pages 361-366
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is known that mechanical strength of 6-4 brass is stronger than 65-35 or 7-3 brass, but the cold-workability is less than α brass. The author has studied on the improvement of cold-workability and other properties. It seems possible to change the structure and some properties by combined heat treatments with cold rolling.
One of the effective conditions is to carry out tempering from 500°C to 600°C after 70% cold rolling following quenching at 820°C. When the rolling reduction is less than 50%, these treatments are not effective.
In consequence of these treatment, 6-4 brass has more elongation in comparison with ordinaty 6-4 brass which has the same strength. It is also found that the variation of the Erichsen value is not clear, but the deep drawability and bending workability are clearly changed with the tempering temperature and time.View full abstractDownload PDF (1867K) -
Nobumitsu \={O}hashi, Kenzo Igaki1964 Volume 28 Issue 7 Pages 366-371
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSingle crystals of PbSe were grown by the Bridgman technique. Specimens were heat-treated at various temperatures and under various selenium vapor pressures in order to control the deviation from stoichiometry. Cooling along the p-n transition i-boundary by the simultaneous control of the specimen temperature and of selenium reservoir is found to be efficacious in obtaining the uniform specimen with a low carrier concentration. The carrier concentration of the specimen was determind from the Hall effect measurement and was shown as a function of the partial pressure of selenium during heat-treatment. The P (selenium pressure)-T (temperature)-x (composition) diagram for PbSe and its stable range were given. From the analysis of the experimental results, the concentration of vacancies on lead and selenium sites in thermal equilibrium can be represented as KS=[VPb−][VSe+]=1043.8exp(−1.78⁄kT).View full abstractDownload PDF (1656K) -
Yûnoshin Imai, Hiroshi Sasaki1964 Volume 28 Issue 7 Pages 371-378
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of some prior heat treatment on the austenitic grain size and grain growth characteristics of steel and the behavior of aluminum nitride in steel were studied. The correlation between aluminum nitride and austenitic grain size were studied in detail. As a result, the coarsening temperature of austenitic grain was found to decrease by heat treatment in the temperature range at which aluminum nitride aggregates or dissolves in the matrix. However, fine grains were obtained by heat treatment in the temperature range of the maximum precipitation of aluminum nitride: these phenomena were observed only in the aluminum treated steel, not in the Si+Mn treated steel.View full abstractDownload PDF (1884K) -
Minoru Nemoto, Shigeyasu Koda1964 Volume 28 Issue 7 Pages 378-384
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn investigation has been carried out on preferential precipitation phenomena in an aluminium-5.5 wt% silver alloy using transmission electron microscopy. During aging at temperatures below 250°C of quenched and a few per cent tensile deformed specimens, narrow stacking faults were formed in each dislocation induced by the tensile deformation before aging and these stacking faults acted as nuclei for γ′ precipitates. When thin foils prepared from the same specimens were heated in the electron microscope using a hot stage, all dislocations were extended, but most of their configurations remained unchanged during the early aging. However, at the same time, nucleation of γ′ precipitates was observed at the surface of the foils and it reduced the preferential precipitation at dislocations. Observations of interaction between dislocations and precipitates in the deformed and aged specimens showed that most moving dislocations cut through these narrow stacking faults of dislocations and the dislocation cell structures were formed in a smilar way to those observed in the solid solution state of the alloy.View full abstractDownload PDF (3537K) -
Toranosuke Kawaguchi, Mitsuru Nagakura, Kimiyuki Kamino, Shigeo Yoshiz ...1964 Volume 28 Issue 7 Pages 384-390
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis study deals with the improvement of Magnetic properties of Mn-Al Magnet. 72 wt%Mn-Al alloys to which 0.5∼16 wt%B, Mo, Se, Te, W, and Zr were added, were prepared by means of melting in Argon atmosphere. Magnetic properties were measured on the specimens water-quenched from 1100°C, and subsequently tempered at the temperatures of 250° to 600°C for 2 hrs.
The remarkable improvements in magnetic properties were found by the addition of B, Te, and Zr. Especially by the addition of B, some interesting phenomena were observed: A considerable amount of ferromagnetic phase appeared at the water quenched state, and the hysteresis loop showed a snaky form.
In the microscopic observation, a needle shape compound appeared as the secondary phase in the alloys containing B.View full abstractDownload PDF (2338K) -
Hakaru Masumoto, Takeo Kobayashi, Kiyoshi Watanabe1964 Volume 28 Issue 7 Pages 390-396
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present investigators already measured the magnetic properties of cobalt-rich Co-Al alloys, and found a new magnet alloy “Malcolloy” three years ago, which has a high coercive force of 1,200 Oe. So they further have investigated the influence of the addition of nickel on their properties, and have found that the coercive force of Co-Al alloys has been increased generally by the addition of nickel: an alloy with the content of 65.46%Co, 14.74%Al and 19.80%Ni shows a coercive force of 1,500 Oe, a residual magnetic flux density of 3,200G and a maximum energy product of 1.45×106 G·Oe when tempered at 525°C for 15 hours after water-quenching from 1370°C and is forgeable at high temperatures. These alloys consist of many ferromagnetic elongated particles about 200∼1000Å in mean diameter dispersed in the matrix of non-magnetic β phase. Consequently it may be concluded that the high coercivity of these alloys is mainly caused by the existence of the small particles, each of them being composed of a single magnetic domain.View full abstractDownload PDF (2027K) -
Fumitoshi Nakamura, Seizo Saito, Kunio Okabayashi1964 Volume 28 Issue 7 Pages 396-402
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn general, the wear tests have been done at an arbitrary frictional interval. However, the effect of the frictional interval on wear has never been clear and it is not too much to say that this is a blind point of the wear study.
This study was designed to clarify the relation between frictional interval and wear.
The wear tests were carried out with carbon steel by dry friction, the results of which are as follows.
(1) There is the frictional interval or the transition point which changes the wear mechanism.
(2) The frictional interval is considered a chief factor of wear and has close relation with the temperature of the worn surface.
(3) The stationary wear loss at a short frictional interval is greater than that at a long frictional interval and the initial wear loss shows an opposite tendency.View full abstractDownload PDF (1730K) -
Zenji Nishiyama, Muneo Oka, Hiroshi Nakagawa1964 Volume 28 Issue 7 Pages 403-407
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe structure of cold-rolled Hadfield steels (1.17%C, 12.48%Mn) subjected to 30% cold-rolling at room temperature has been studied by means of transmission electron microscopy. In the electron micrograph a number of parallel fine bands (50∼100Å) are found, in addition to stacking faults and plates of ε-martensite (called ε′-phase) which were previously observed. From the result of the analysis by selected-area electron diffraction, the fine bands newly found are interpreted as deformation twins formed on (111) planes of the matrix. The formation of such fine deformation twins is considered to cause the work hardening of Hadfield steel with the ε′-phase and the stacking faults.View full abstractDownload PDF (919K) -
Zensaku K\={o}zuka, Y\={o}ichi Nakai, Jyoichir\={o} Moriyama1964 Volume 28 Issue 7 Pages 407-412
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe thermodynamic properties of the liquid Zn-Pb alloys above 1000°C and the vapor-liquid equilibrium composition of this system at an atmospheric pressure have been determined by the application of EMF measurements. The cell used in this work was a closed type and made of quartz. Measurements were carried out over a temperature range of 850° to 1050°C. From these experimental results the liquid alloys were found to exhibit considerable positive deviations from Raoult’s Law and nonregular behavior. On the basis of these experimental results and some other results, the following equations were derived for ln γ as a function of temperature and alloy composition.
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\ oindentFrom these equations the vapor-liquid equilibrium of the Zn-Pb system at an atmospheric pressure was determined and it has been found that the ratio of NPb(g)⁄NPb(l) for the infinite dilute solution was nearly equall to 0.012. Furthermore it has been confirmed that some calculated values from these equations were in good agreement with reliable experimental data over a temperature range from 600° to 1100°C.View full abstractDownload PDF (1239K) -
Tatsuro Kunitake1964 Volume 28 Issue 7 Pages 413-420
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of austenitizing temperatures, from 800°C to 1000°C, on (a) the transformation regions in the CCT diagram and (b) the critical cooling rates for various amounts of bainite and pearlite formation, has been determined for a 0.6%C Cr-Mo-V low-alloy steel with bainitic hardenability. The observations on the variation in the state of austenite with austenitizing conditions were also conducted. The relation between the transformation characteristics and the state of austenite was discussed. The austenite grain size affected pearlite-range transformation remarkably, but its effect on bainite and martensite transformation was very small. The effect of a small amount of undissolved carbide which was observed when austenitizing temperatures were low existed in two ways: One was the decrease in the alloy content, especially the lowering of the C content in the austenite matrix, which accelerated both pearlite and bainite transformations and raised the Ms temperature. The other was the accelerating effect arising from the existence of carbide itself. This effect was observed in the bainite transformation as the increase in critical cooling rates for the small amount of transformation and the elevation of transformation temperature.View full abstractDownload PDF (1532K) -
Emiko Sudo, Haruno Ogawa1964 Volume 28 Issue 7 Pages 421-425
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe method of S.W. polarographic determination of tin in iron and steel is interfered with lead, chromium, etc. The authors solved this problem by using the EDTA mask-Be (OH)2 precipitation technique. In addition, the sensitivity of this method was increased. A procedure was recomended as follows.
0.5 g of iron or steel sample was dissolved in hydrochloric acid and then nitric acid was added to oxidize ferrous ion. The solution was treated with EDTA and beryllium solution for masking of iron and others. Heating just to the boiling point, ammonia water was added until the precipitation of beryllium hydroxide completed. After cooling, the precipitation was filtered and washed with (2+100) ammonia water until the red color of Fe-EDTA chelate was disappeared. The precipitate was dissolved with 25 mL of (1+1) hydrochloric acid and the solution was transferred to a 50 mL volumetric flask. After 1 mL of 0.5 v/v% polyacrylamide (PAA) aqueous solution was added and diluted to volum, tin was determined by the S.W. polarograph (−0.3 V∼−0.6 V vs.Hg pool). Otherwise, instead of PAA, 10 mL of 2.5×10−3 M tetraphenylarsoniumchloride-50% ethanol solution might be used. In this case, tin was determined by the A.C. polarograph.
Using the 0.5 g sample, it was possible to determine 0.002% tin by the S.W. polarographic method, 0.005% tin by the A.C. polarographic method with tetraphenylarsoniumchloride-hydrochloric acid supporting electrolyte and 0.01% tin by the A.C. polarographic method with hydrochloric acid supporting electrolyte.View full abstractDownload PDF (931K) -
Seiichi Karashima, Hiroshi Oikawa1964 Volume 28 Issue 7 Pages 426-431
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDislocation configurations in a commercial molybdenum deformed in tension (1∼11%) at various temperatures (R.T.∼700°C) have been studied by transmission electron microscopy. Dislocations are usually joggy and nonuniformly distributed. Even at small strain many dislocation loops and cusps are observed. As the amount of strain is increased, dislocations become tangled and a cell-structure is clearly developed. The cell dimension seems to depend neither on the amount of strain nor on the temperature of deformation, having a size of 2∼3 μ.
Little changes in general features of dislocation arrangement occur when varied the temperature of deformation. With increase in the temperature of deformation, the average dislocation density decreases, while the dislocation density in cell-walls remains nearly constant within the temperature range examined.
A linear relationship is found between the flow stress and the square root of the average- and/or cell-wall-dislocation density at room-temperature deformation.View full abstractDownload PDF (726K) -
Yoshihiro Tsunoda, Hidemaro Araki, Hisashi Seki1964 Volume 28 Issue 7 Pages 431-432
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (280K)
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