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Volume 27, Issue 9
Displaying 1-10 of 10 articles from this issue
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Hisayoshi Maeda, Toshio Kawabe, Yoshihito Endo1963 Volume 27 Issue 9 Pages 415-418
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDie Schmiedestücken des Baustahls werden oft nach Erhitzung im Härteofen gehärtet. Meistens aber werden sie mit der Angst für Härtespannung und Härteriss im verhältnismässig langsam kühlenden Öl abgeschreckt. Unter diesen Umständen beim Stahl mit hohen Umwandlungs-geschwindigkeit wie Kohlenstoffstahl wird die Neigung zur Undurchhärtung grösser.
Aber das gewachste Austenit-Korn verringert die Umwandlungs geschwindigkeit.
Nach die verschiedenen Versuche haben wir an den Stahl mit mittelerem Kohlenstoffgehalt die grund-legenden Daten über die Härtbarkeit von Schmiedestücken festgestellt: (1) Je höher die Erhitzungstemperatur wird, desto grösser wird die austenitische Korngrösse. Es ist sehr merkwürdig bei der Temperatur mehr als 1000°C. Mit dem Aufstieg der Temperatur wird die Umwandlungs geschwindgkeit in der Regel langsam. (2) Da die austenitische Korngrösse des Schmiede-Härtungsstahls kurz vor der Härtung grösser als die Korngrösse des ordentlichen Härtungsstahls ist, so steigt die Härtbarkeit auf und wird seine Härteeignungseigenschaft 3 bis 4-fach wirksamer.View full abstractDownload PDF (412K) -
Kunio Shiobara, Yoshinobu Sawada, Susumu Morioka1963 Volume 27 Issue 9 Pages 419-423
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe anodic behaviour of seventeen annealed iron-chromium alloys ranging in composition from 0 to 100%Cr in deaerated sulphuric acid solution at 25°C was investigated systematically. The semi-conductor type potentiostat was used for polarization messurement. A number of properies such as spontaneous or corrosion potential, passivation potential, Flade potential, initial and secondary maximum corrosion currents (passivation current), passive current, trans-passive current were compared with the change in composition of alloys. It has been found that the alloys with more than 22%Cr give a negative loop in anodic polarization curve at potential range between −0.4 volt and 0 volt (vs S.C.E), indicating that these alloys, at these potential range, become spontaneously passive by hydrogen iron.View full abstractDownload PDF (717K) -
Kensuke Mutsuzaki, Masatoshi Suzuki, Eiichiro Kawai1963 Volume 27 Issue 9 Pages 424-427
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe metal surfaces eroded by electrical-discharge machining are heated and subsequently cooled so extraordinarily rapid that they show many abnormal characteristics never found by other treatments.
Ag-Cu binary alloys, which forms a typical partially soluble eutectic system in equilibrium were selected in this study. They were eroded by electrical-discharge machining, and their surface layers were examined by X-ray diffraction.
They were rapidly heated and cooled between gaseous state and solid state at room temperature for only several micro-seconds during the spark discharge were maintained. As a result of the fact, the super-saturated solid solution of face-centered-cubic lattice were produced over the whole range of composition.View full abstractDownload PDF (303K) -
Kensuke Mutsuzaki, Masatoshi Suzuki, Eiichiro Kawai1963 Volume 27 Issue 9 Pages 427-432
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe surfaces of sintered carbide alloys eroded by the electrical-discharge machining were examined by X-ray diffraction.
The results obtained were as follows:
(1) In WC-Co series, the carbide WC, which has a hexagonal lattice in normal state, was transformed to a close-packed structure (either face-centered-cubic or hexagonal-close-packed) in the eroded surfaces.
(2) In WC-TiC-Co series, the continuous series of solid solution of WC (abnormal face-centered-cubic structure above mentioned) and TiC (face-centered-cubic structure originally) were discovered.View full abstractDownload PDF (497K) -
Fumitoshi Nakamura, Seizo Saito, Kunio Okabayashi1963 Volume 27 Issue 9 Pages 433-438
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the experiment of wear, the wear phenomena will change its behaviour when the experiment is carried out under different conditions from the initial conditions in the midst of experiment, and also the same circumstance will occur when the one side of a specimen that was rubbed each other is replaced by the new one.
These phenomena may depend upon the history of wear.
It is the purpose of this paper to show that the prewearing has an important effect on the subsequent wear.
Experiments were done under the dry condition with carbon steel, and the temperature of wearing surface and frictional force were measured.
From the experimental results it was found that the prewearing was very important and that, when the large specimen was replaced by the new one in the midst of experiment, the secondary initial wear was regenerated on the small specimen.View full abstractDownload PDF (518K) -
Minoru Tanaka, Shigetomo Nunomura1963 Volume 27 Issue 9 Pages 439-444
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe purpose of this study is that the loads and the shapes of the load-time curves in the Charpy standard impact test are compared with the tensile strength data for the structural steel in three grained conditions (ASTM GS No. 4, 8 and 9). And three types of notched specimen were used in the Charpy impact test. The upper tensile yield stresses of these steels have been determined experimentally under three constant rates of stress, about 1, 102 and 107 kg/mm2sec, at temperatures of −196°C, −70°C and 16°C. A characteristic value σ0, i.e. the critical tensile strength divided by the plastic stress concentration factor, is easily obtained from the load-time curve in the Charpy impact test. The transition temperatures of steel in the Charpy impact test are predicted as the temperature at which the upper yield stress is equal to the value of σ0 obtained for the of stress rate at the root of notch. These predicted temperatures were found to agree remarkably well with the 15 ft-lb transition temperatures. The results of this study also provide that the Charpy impact test becomes more quantitative by observing the load-time curves, and may be used in place of the tensile test under high stress rate of about 106 kg/mm2sec.View full abstractDownload PDF (627K) -
Takasi Sakaki1963 Volume 27 Issue 9 Pages 445-449
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn experiment was conducted on the photometric method with sodium diethyl dithio carbamate, for the purpose of establishing a rapid and accurate determining method for obtaining the amount of cobalt in metallic nickel and ferro-nickel. When cobalt coexists with EDTA in the sample solution, the complex salt of cobalt diethyl dithio carbamate will form quantitatively in an acetic acid solution of pH 3.0∼3.7. This complex salt can be extracted quantitatively and readily by the use of carbon tetra chloride. This extracted solution has an absorption maximun at 365 milli microns. However, since the maximum absorption of the blank solution is also in the same wave length range, it will be suitable to use a wave length of about 390 milli microns where the absorption of the blank solution is comparatively small. At pH 3.0∼3.7, the effect of copper, bismuth, certain irons, nickel and manganese which can not be masked by EDTA, can be eliminated by the use of mercuric acetate.
As a result of the experiment, the author was able to establish a method in which 0.02 to 2 per cent of cobalt can be measured quantitatively and accurately in about fifteen minutes. The amount of cobalt in actual samples was measured by this method, and satisfactory results were obtained.View full abstractDownload PDF (311K) -
Takasi Sakaki1963 Volume 27 Issue 9 Pages 449-453
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis experiment was conducted for the purpose of establishing a method for a simple and accurate quantitative analysis of copper and bismuth in ferro-tungsten. First of all, the precipitation condition for copper and bismuth when using thionalide, a reagent in lieu of hydrogen sulfide, was studied. Next, the effect of the elements coexisting at the time of Cu-DDTC Method and BiI4− Method was observed.
Thionalide is easier to handle and higher in separation accuracy compared with hydrogen sulfide.
The thionalide complex salt of copper and bismuth will form quantitatively in a short period in a 1 to 2 N sulfuric acid solution containing tartaric acid. These complex salts are readily filtered, and the filtered precipitation can be washed with distilled water. As for the Cu-DDTC Method, there is no significant effect even if 0.5 mg each of antimony, tin, arsenic and lead, and 10 mg of tungsten are contained in the separated sample solution. The existence of bismuth will be harmful.
However, if the determination of bismuth is performed, and corrections are made, it will not be necessary to separate the bismuth.
In the BiI4− Method, there is no significant effect even in case 5 mg of copper and 0.5 mg each of antimony, tin, arsenic, and lead are contained in the separated solution.
As a result of the experiment, the author was able to establish an analysing method which can be done in only one-third of the time required by the JIS Method and has a comparatively high accuracy. A quantitative analysis of copper and bismuth in actual samples were performed and satisfactory results were obtained.View full abstractDownload PDF (385K) -
Toshio Doi1963 Volume 27 Issue 9 Pages 454-459
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffect of zirconium upon the softening, ageing, grain size and micro structure of Cu-1.1%Ni-0.22%P alloy has been investigated.
Age hardenability of copper alloys containing 1.0∼1.2% nickel, 0.20∼0.24% phosphor and 0.1∼0.2% zirconium are large, while grain growth is suppressed.
Grain refinement of Cu-Ni-P alloys by addition of zirconium is due to the presence of precipitate containing zirconium atom.
Relation among volume fraction of precipitate f, mean curvature of precipitate Ri and mean curvature of grain boundary R is given by R⁄Ri=0.15⁄f.
Precipitation has been found in the alloys containing zirconium up to 0.2% at temperatures of 300° and 500°C respectively, but crystal structure of the precipitates can not be identified by X-ray diffraction technique.View full abstractDownload PDF (1075K) -
Hakaru Masumoto, Takeo Kobayashi1963 Volume 27 Issue 9 Pages 459-460
Published: 1963
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe thermal expansion coefficient and the temperature coefficient of Young’s modulus of the iron-platinum alloys have been determined with a vertical dilatometer previously designed by the present investigators and by means of a vibrator-controlled oscillator, using electrostatic transducer system, respectively. It has been found that the alloys containing about 53.5∼57.0% of platinum have a negative coefficient of thermal expansion; the largest mean value in the temperature range 0∼40°C is −23.68×10−6 for the alloy containing 56.0% of platinum, and that the alloys containing about 51.0∼69.0% of platinum have a positive coefficient of Young’s modulus; the largest mean value in the same temperature range is +161.5×10−5 for the alloy containing 55.0% of platinum.View full abstractDownload PDF (145K)
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