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Volume 28, Issue 3
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Masanobu Miyake1964 Volume 28 Issue 3 Pages 111-116
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA kinetic study of the dissolution of solid Ni and Cu in liquid Bi has been made under the dynamic and isothermal conditions. The experiments were carried out at given temperatures in the range of 370°∼475°C and at constant peripheral speeds of rotating solid specimen in the range of 0∼52 cm/sec, following the dissolution process was examined by analyzing the whole sample drawn from a reaction vessel after the predetermined time of dissolution. The rates of dissolution of Ni and Cu in liquid Bi thus obtained have been found to conform to an unimolecular reaction law expressed in the form of n=ns{1−exp(−k·S⁄V·t)}, which is identical to one applied previously to these systems under the static condition. The values of the solution rate constant obtained for both systems were significantly higher than those under the static condition and increased in proportion to about six-tenths power of the peripheral speed. From these facts it was confirmed that the rates of dissolution of Ni and Cu in liquid Bi can be determined by the rate of transfer of dissolved particle through the diffusion layer in solid-liquid interface. It was also shown that the evaluated values of activation energy for dissolution of both systems were appreciably lower than those obtained under the static condition and decreased slightly with the increase in peripheral speed. These results are reviewed on the basis of the diffusion mechanism in liquid.View full abstractDownload PDF (775K) -
Masanobu Miyake1964 Volume 28 Issue 3 Pages 116-121
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA Kinetic study has been made on the dissolution of solid Ni in liquid Cu-Bi and Cu in Ni-Bi solutions of various concentrations. The experiments were carried out under the static and isothermal conditions in the temperature range of 450°∼550°C and the dissolution process was followed by analyzing small samples drawn successively from the liquid solution during the course of a run. It was found that the dissolution process for these systems followed the same expression of the form of n=ns{1−exp(−k·S⁄V·t)} as that which was applied to the dissolution process of these solid metals in pure liquid Bi, and that the obtained values of solution rate constant decreased linearly with the increasing Cu or Ni concentration in solutions. On the other hand, it was shown that the solubilities of Ni in Cu-Bi solutions decreased with the increasing Cu concentration in solution, while those of Cu in Ni-Bi solutions increased with the increase in Ni concentration. Assuming a stronger mutual interaction between Ni and Cu atoms coexisting in solution, an explanation for the dissolution mechanism of these systems are proposed.View full abstractDownload PDF (1037K) -
Tooru Furukawa1964 Volume 28 Issue 3 Pages 121-128
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of austenitizing, cold rolling and aging conditions on the mechanical properties, corrosion resistivity and microstructure of 17-7 PH stainless steel containing 1.15%Al or 1.54%Al were investigated. The results obtained are summarized as follows: (1) When the austenitizing temperature was in the range of 750°∼825°C, no remarkable difference was observed in the mechanical properties of this steel after aging.
(2) As for the steels containing 0.73∼1.54%Al, a rapid increase in hardness took place in the early stage of aging, following which a slow hardening continued to the maximum hardness. While the increase in the Al content which promoted the hardness augmentation in the early stage delayed the peak hardness to be reached.
(3) An experimental formula for the relation between the Al content and the aging time required to obtain the best mechanical properties at each aging temperature is as follows: t = 5.144×(Al%)^1.476×10^10438/T-14
(4) In 40 wt% nitric acid solution (boiling), all the specimens attained a passive state and showed excellent corrosion resistance.
(5) In 10 wt% sulfuric acid solution (30°C), specimens which were aged at 400°∼500°C after austenitizing treatment for the duration in sufficient to get the maximum hardness or aged after cold rolling, attained a passive state and showed good corrosion resistance.View full abstractDownload PDF (2432K) -
Shunichiro Abe1964 Volume 28 Issue 3 Pages 129-136
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to clarify the varying behaviors of toughness in highly hardned tool steels by different heat treatments, the author first devised static and impact torsion testers. Then the effects of both tempering and austenitizing temperature on the toughness of highly hardened carbon tool steels were examined with a test piece in a particular shape by these testers. In addition, several kinds of hardened high speed steels were also tested by the same method to compare the toughness with carbon tool steels.
According to the results, in carbon tool steels the several expressing values of toughness are gradually improved with the tempering temperature, but they have a peak in the vicinity of 200°C and a valley around 250°C in the tempering range up to 300°C and these changes have an analogous tendency in both tests except the clearer discrimination in the impact torsion values. On the other hand in the same hardness level an austenitizing temperature which gives the best mechanical properties in static torsion test is about 40°∼80°C lower than that for the maximum impact energy.
It is also revealed that high speed steels under a highly hardened condition are much tougher than hardened carbon tool steels in the same hardness level of about 64 Rc.
Thus it is probable that the high wear resistance of tools made from high speed steels may mainly owe to their higher toughness, because the excellent toughness at the tool edge markedly decreases the minute chipping during the cutting, and therefore this toughness in many hardned tools is believed to be one of the most important properties against premature wear.View full abstractDownload PDF (2533K) -
Shunichiro Abe1964 Volume 28 Issue 3 Pages 137-144
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to increase the reliability on the future measuring value of toughness of highly hardened tool steels, some experiments on the reproducibility and the accuracy of testing values measured by the static and impact torsion tester, devised by the author, have been repeatedly carried out with parallel specimens of the same composition and shape.
These specimens made from carbon tool steel containing 0.80%C were hardened under the same condition and tempered at different temperatures between 100° and 200°C.
They were then fractured by both static torsion and impact torsion respectively to measure several mechanical properties in static test and torsion impact energy, following which the mean values and their standard deflections of the measured values obtained from eight or ten parallel specimens coresponding to the different temperings were calculated. The accuracy of the calculations was scrutinized performed by means of statistics.
As the results, it has been clarified that the yield strength, maximum torque, modulus of rigidity and elastic work of deformation consumed up to fracture can be reproduced in a smaller standard deflection than that of impact energy, and that, as the discrimination for these expressing values between temperings at 150° and at 200°C is far larger in impact energy than in the several properties of static torsion, impact torsion test may have better sensibility in detecting the toughness of highly hardened tool steels in spite of its larger scattering in the testing values.View full abstractDownload PDF (1897K) -
Toshisada Mori, Eiji Ichise1964 Volume 28 Issue 3 Pages 145-148
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe solubility of nitrogen in austenite was measured on iron-cobalt and iron-tungsten alloys in order to study the effects of alloying elements on the activity of nitrogen and to determine the interaction parameters of nitrogen with alloying elements. The measurements were performed within the austenite range: the experimental temperatures were 1050°, 1150° and 1250°C and the percentages of additives were up to ca. 80% for cobalt and up to 2.5% for tungsten. Solubility measurements were carried out by a quenching method. The results show that cobalt increases the activity of nitrogen, but tungsten decreases it. The interaction parameters are
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The relationship between interaction parameters and atomic number or temperatures was also discussed.View full abstractDownload PDF (939K) -
Yoshito Yamada1964 Volume 28 Issue 3 Pages 149-155
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSResidual resistance ratio was measured for the evaluation of the purity of a zone refined copper which had an original purity of 99.999%. Spectrographic analysis was also carried out. Size effect of wire specimens was studied, and ρB×l=7.6×10−12 ohm-cm2 was obtained, where ρB is the specific resistivity for bulk material and l is the mean free path of electrons. Two kinds of specimens obtained from the same ingot, namely drawn wire and chipped specimens were studied and the latter specimens indicated R4.2⁄R273=6.0×10−4, in the purest part of the ingot. The observed value is presumed to correspond to R4.2⁄R273=5.4×10−4 for bulk copper, if the size effect is taken into account. Comparing with the zone refined copper, residual resistance retio of three pieces of commercial copper wire were also measured.View full abstractDownload PDF (1695K) -
Takashi Kimura, Heihachiro Hirabayashi, Mutsuo Tokuyoshi1964 Volume 28 Issue 3 Pages 156-162
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe mechanical and physical properties of strips produced by the powder rolling method were investigated with three kinds of domestic iron powders, such as nitriding-process iron powder, sponge iron powder, and mill-scale reduced iron powder. In addition, the effect of particle size on the above properties was also investigated.
As reported in previous papers on Höganäs sponge iron powder, with the increasing powder feed in powder rolling, the rolling load, thickness and apparent density of green strip were increased and the various properties of sintered and cold rolled strips were improved. The rolling load and thickness of green strip were more affected by the flowability more than the particle size of powder. The better mechanical and physical properties of sintered and cold rolled strips were obtained in the order of purity of powder. The effect of particle size of powder on the properties of cold rolled strip was observed: With the decrease in particle size, the elongation increased, but, on the contrary, the larger the particle size, the better the magnetic properties of cold rolled strip.View full abstractDownload PDF (1472K) -
Takashi Kimura, Mutsuo Tokuyoshi, Heihachiro Hirabayashi1964 Volume 28 Issue 3 Pages 162-168
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSUsing the powder rolling method, an attempt has been made to clarify the relationship between the microstructure and the physical and mechanical properties of sintered and cold-rolled strips made from three kinds of domestic iron powders. In the case of sintered strips, the voids in strips were decreased with the increase in powder rolling load and with the decrease in particle size, but the grain size of strips was scarcely affected. The properties of sintered strips were affected mainly by the voids in strips rather than the grain size. In the case of sintered strips, the voids were diminished and the grain size of strips became finer as the powder rolling load increases and the size of powder particles becomes smaller. With the increase in purity of powder, the microstructure of strips showed more distinct polygonal structure, corresponding to the increase in apparent density and elongation of strips. The grain size of sintered strips was finer than original particle size of powder and that of cold-rolled strips was much finer than that of sintered ones. These results suggest that the high purity iron strips containing small grains can be produced by the powder rolling method.View full abstractDownload PDF (2092K) -
Eiji Miyoshi1964 Volume 28 Issue 3 Pages 168-174
Published: 1964
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is well known that the creep-rupture characteristics of 18-8 stainless steel stabilized by titanium is remarkably affected by its preliminary heat treatment. This is a part of the study persuing the reason of this characters from the metallographical point of view. The relation between carbide precipitated in steel and its heat treatment was studied. Carbides were extracted from steel and their composition was chemically analysed. Preliminarily all the samples were solution treated at the highest temperature of 1300°C, in order to eliminate effects of the carbide-residue in steel and grain size. The carbon and titanium contents change with the heating temperature and duration. Maximum precipitation was observed over the temperature range of 800° to 950°C. The titanium content dissolved in steel promote the carbide precipitation. The chromium content in carbides showed the maximum in steel containing a larger amount of titanium at the initial stage of heating at 700°C. The preliminary solution treatment at higher temperatures delays the initiation of the carbide precipitation.View full abstractDownload PDF (1684K)
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