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Volume 21, Issue 3
Displaying 1-16 of 16 articles from this issue
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R. Yamada, K. Yokoyama, T. Nakamura, F. Urushibara1957 Volume 21 Issue 3 Pages 141-145
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe quench age-hardening of carbon steel melted and cast in vacuum was investigated by use of 11 species of vacuum-melted and atmospheric-melted steels with different carbon contents ranging from about 0.02 to 0.87% and 7 species of commercial steel specimens chosen for the sake of comparison. According to the experimental results, (1) The as-annealed hardness and the as-quenched hardness of vacuum-melted steel showed lower values than those of steels melted in atmosphere and those of commercial steels. (2) No distinct change of hardness was observed with any specimen in this experiment in the case of quenching from temperatures less than 500°. However, the change of hardness due to aging was most conspicuously observed when specimens with carbon content of about 0.05∼0.1% were quenched from temperatures around 700°. (3) The hardness increase and the increasing rate of hardness of vacuum-melted steel due to aging were lower than those of steel specimens melted in atmosphere or specimens of commercial steels.View full abstractDownload PDF (693K) -
Masayoshi Tagaya, Imao Tamura, Katsutaro Akamatsu1957 Volume 21 Issue 3 Pages 145-149
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBall-Bearing steel containing 0.98% carbon and 1.40% chromium has been subjected to the continuous-cooling transformation study in order to determine the continuous cooling transformation diagram with Liedholm’s method in view of the fact that although many of the continuous cooling transformation diagrams for various kinds of steel have been determined, few curves for high carbon and low alloy steel have been established,and also intending to establish better relationships among the hardenability of steel, its dimension and the cooling ability of coolant than that by M. A. Grossmann according to the findings derived from the continuous cooling transformation diagram and the “Mother Cooling Curve”. The diagram determined here is as shown in Fig. 8. With a view of checking the validity of the diagram so determined, the cooling curves of round bars quenched in various coolants were also measured and compared with the diagram.View full abstractDownload PDF (981K) -
Tatsuo Fujiwara1957 Volume 21 Issue 3 Pages 149-153
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influence of finish condition of the surface such as intergranular oxidation and mechanical scar etc. on the heat-check formation has been studied by disk-like specimens and mandrels made of 5%Cr-Mo-Si Steel. The specimens were heated by induction heating in the same manner as in the 1st report, and the mandrels were used for 10∼life number times hot-pressing. The results obtained are as follows : (1) Heat-treating in lead bath covered with charcoal, the intergranular oxidation proceeded, and the heat-checks formed at austenite grain boundaries. This inclination became more remarkable in heat-treatment in oxidizing atomosphere. (2) Surface scars produced by lathe-tool cutting or emery-paper polishing also effected the heat-check formation (3) Even specimens of which the mechanical scars were removed by electrolytic polishing after being removed perfectly defects in heat-treating did not prevent the heat-checking. However the heat-check decreased under this cond ition and the mandrels’life was prolonged remarkably. (4) The behaviors of the heat-checks of the mandrels were similar to those of the specimens produced by induction heating. (5) The growth of the checks became once slow at a certain depth under the surface, and then sped up again.View full abstractDownload PDF (956K) -
Mayumi Someno1957 Volume 21 Issue 3 Pages 153-157
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA hydrogen or nitrogen atmosphere which contains titanium chloride or silicon chloride vapor is useful for bright heating of stainless steels. The weight changes, the microstructure, the corrosion beh aviores and mechanical properties of stainless steel treated in such atmospheres were observed.View full abstractDownload PDF (682K) -
Sadao Koshiba, Tsuneo Kuno1957 Volume 21 Issue 3 Pages 157-160
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSLately, the demand for dies steel for die casting of aluminum, zinc and their alloys has considerably increased. In the present investigation the authors took up five samples of dies steels containing various quantities vanadium and tungsten, and a series of experiments has been carried out to study the transformation point of the samples and afterward the hardness, the rate of deformation, the tensile strength at elevated temperature, the hot hardness and the microstructure of the samples subjected to different heat treatment were measured. They ascertained from this investigation that the appropriate content of vanadium is about 0.65% at the range of 0.30∼1.10%V, and then adding of about 1.30%W increases the tensile strength at the high temperature of 500∼700°.View full abstractDownload PDF (531K) -
Takao Kawakita1957 Volume 21 Issue 3 Pages 160-163
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been found by the present writer that the initial sharpness of finished cutleries degenerates as time elapses. The string cutting value goes down rapidly in 4 days and thereafter the change becomes very slow.It takes 16 days for the degeneration of the paper cutting value to become very slow.The time-sharpness curves were taken with various samples under various conditions. 30 minutes′ heating at 100° is sufficient to produce remarkable degeneration of the sharpness.The degeneration of sharpness means the increase in the radius of curvature of the top edge of the blade.The change may possibly be considered to be physical. But the writer is inclined to conclude that chemical change is the important factor in the degeneration of initial sharpness of cutleries by ageing.View full abstractDownload PDF (492K) -
Masuji Kyotani1957 Volume 21 Issue 3 Pages 163-166
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been reported in the previous papers that the mechanical properties of metals are improved by “KRK” process which is applied in combination with heating and mechanical force for short periods of time such as a few minutes or shorter. The present paper deals with the effects of “KRK” process on the changes of anisotropy of 2.6% silicon-iron alloy strip. The anisotropy was quantitatively determined by means of torque magnetometer. The results obtained are as follows : The magnetic characteristics of silicon-iron alloy are effectively improved by applying this treatment to the treated strip. That is, the larger torque value is obtained under the conditions in which the tension over the elastic limit at that temperature is applied at a temperature between its recrystallization temperature and 1050° for 5 sec∼15 min. In the case in which strain tempering is applied after the skin pass of few percent cold reduction, this treatment is most effective in magnetic anisotropy. The rotation of crystalline orientation to the direction of magnetization is considered to be accelerated by this treatment.View full abstractDownload PDF (542K) -
Sadao Koshiba, Terumi Nishinuma1957 Volume 21 Issue 3 Pages 166-169
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe writers carried out a series of experiments on the effect of Si on the magnetic properites with four varieties of typical precipitation magnetic alloys, namely, Fe-Ni-Al alloy, Fe-Ni-Al-Co-Cu alloy, anisotropic Fe-Ni-Al-Co-Cu, and Fe-Ni-Al-Co-Cu-Ti alloys. From this experiments,the following results were obtained. Generally,the coercive force decreases as the Si content increases for each magnetic alloys.The residual induction increases as the Si content increases for the magnet alloys of non-magnetic field treatment. In the case of anisotropic Fe-Ni-Al-Co-Cu and Fe-Ni-Al-Co-Cu-Ti alloys,residual induction increases as the Si content increases up to about 1%, but decreases remarkably when it rises beyond 1%.And then the desirable Si content for each type of magnet alloys was decided.View full abstractDownload PDF (488K) -
Riitsu Takagi, Kiyoshi Tamura1957 Volume 21 Issue 3 Pages 169-172
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe construction and the performance of an experimental vacuum-hot press for refractory hard metals is described. A cylindrical graphite die,up to 6 cm in diameter, is directly heated by passing an electric current supplied by a 50 kVA-transformer, the secondary voltage of which is controlled by a 25 kVA-induction regulator in the range 0∼10 V. The density, electrical resistivity, hot hardness, resistance against corrosion, oxidation and thermal shock as well as the high temperature modulus of rupture of the specimen produced in this apparatus at the optimum temperature of 1430° were measured. It is concluded that the properties of the specimen so produced are superior to those of the specimen produced by cold-pressing of powders and subsequent vacuum-sintering.View full abstractDownload PDF (638K) -
Yoshikazu Hosoi, Eiichi Sawato, Mamoru Yukawa1957 Volume 21 Issue 3 Pages 172-176
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this experiment the Vickers hardness was measured on the Al rods extruded with the 88.6% reduction circle die at 400° and 500° and its hardness changes in annealing so that we might investigate how extension and compression of the rod extruded at high temperature have effect upon its annealing process. Results obtained are as follows : (1) When worked below the plastic deformation range, the extruded Al rod becomes soft and when worked more it is hardened as cold worked Al. This is remarkably observed in the case of the rod extruded at 500°. (2) The rod softened by slight working is hardened in lower temperature annealing, while the rod hardened by more working is soften just like rods simply extruded. (3) The softening point,by recrystallization may-be, is no effected by such slight working as makes the rods soften. When worked more it shifts to considerably lower temperature and it is remarkable in the rod extruded at 400°. The details mentioned above are also discussed referring to X-ray photographs (by CuKα line).View full abstractDownload PDF (790K) -
Hiroshi Asada, Eihachiro Tanaka, Kichizo Koike, Saburo Morimoto1957 Volume 21 Issue 3 Pages 176-180
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSExtrusion pressure and the form of the pressure curve for wrought aluminium alloys were investigated by an automatic recorder on 300 ton extrusion press. Aluminium alloys have a strong tendency to adhere to the working tool and their deformation resistance varies delicately in accordsnce with cooling of the billet. Therefore the initial pressure has a linear relation with the logarithmic extrusion ratio, but the pressure curves for the extrusion by direct and inverted methods into rods or tubes do not show the ideal form. The influence of extrusion speed, temperature and soaking of billet on the extrusion pressure and the form of pressure curve were examined and discussed in connection of the results obtained. The values of resistance of extrusion at 450° for 2S, 3S, 63S, 53S, 61S, 17S, 24S and 52S were measured as 9.39-6.34, 9.86-9.28, 11.8-9,8, 12.9-9.78, 14.5-12.55, 20.7-16.86, 24.2-19, 25 and 23.1-20.95, respectively.View full abstractDownload PDF (555K) -
Hiroshi Asada, Kichizo Koike, Saburo Morimoto, Eihachiro Tanaka1957 Volume 21 Issue 3 Pages 180-183
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of the die-shape upon the extrusion pressure for aluminium alloys were examined and the following results were obtained. (1) The extrusion pressure did not change by the variation of the shape of die-hole, while the circumference of hole was raised to 1.4 times. (2) Both the dies of which the lead-in has a radius of curvature and the conical die decrease the extrusion pressure in proportion to the increase of the radius of curvature and conicity. (3) The pressure when using a multiple-hole die was larger than that for the single hole die with the same total sectional area. (4) The bearing length of the die gives only very small influence to the initial pressure, but larger influence to the secondary pressure which is caused by the friction effect. The secondary pressure rises to twice the initial pressure, when the bearing length becomes 5.8 times.View full abstractDownload PDF (601K) -
Susumu Yoshida, Shigetake Okamoto, Takashi Araki1957 Volume 21 Issue 3 Pages 183-186
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe corrosion rates of binary titanium alloys were determined in sulphuric, hydrochloric and nitric acids, aqua regia, acetic, formic and oxalic acids, ammonia water and NaOH, NaCl, FeCl3, AlCl3 solutions at ordinary and boiling temperatures. The added elements were Al, Ag, Sn, Si, Cr, Mn, Fe, Co, Ni, Cu, W and Mo. The alloys were arc-melted in argon atmosphere. They were hot and cold rolled to 1 mm thick plates and then cut into specimens for the corrosion test. Among the tested alloys, Ti-Mo alloys containing more than 20%Mo were shown to be highly resistant to hydrochloric and sulphuric acids which attack pure titanium severely. But the superior corrosion resistance of titanium in nitric acid is deteriorated by addition of Mo. The comparatively poor corrosion resistance of titanium in formic and oxalic acids and AlCl3 solution was shown to be much improved by addition of appropriate elements.View full abstractDownload PDF (527K) -
Tokushichi Mishima, Ryukiti R. Hasiguti, Yasuo Kimura1957 Volume 21 Issue 3 Pages 187-190
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe magnetic properties of Alnico 5 magnet (8%Al, 14%Ni, 24%Co,3%Cu and Fe) depend sensitively on heat-treatment,that is cooling in magnetic field and subsequent aging. The changes of coercive force, residual induction, maximum energy products and powder patterns of the magnetic domain were observed during these processes. The coercive force (or residual induction) changes logarithmically with the cooling rate. This empirical relationship is satisfied with or without magnetic field when cooling from 1,000 to 700°. The changes of coercive force as a function of aging time after cooling in magnetic field can be expressed by Austin-Rickett’s formula. These results are explained qualitatively, if we consider that during cooling in magnetic field the nuclei of meta-stable phase are mainly formed and then the growth process takes place during subsequent aging. In the cooling rate between 0.8 and 7°/sec, the activation energy of subsequent aging process is 46,000±2,000 cal/mol which is independent of the cooling rate.View full abstractDownload PDF (678K) -
Shuichiro Takahashi1957 Volume 21 Issue 3 Pages 190-194
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe stress dependencies of the internal friction and Young’s modulus of cold-rolled and low-temperature-annealed specimens of α-copper alloys (mainly Cu-Zn alloys) were investigated at the frequencies of about kilocycle and at room temperature. It was found that there are two kinds of critical stresses; the one is the first critical stress beyond which a remarkable increase of the internal friction and a remarkable decrease of Young’s modulus begin to take place simultaneously, and the other is the second critical stress beyond which the internal friction and Young’s modulus do not change reversibly with the stress applied. The former corresponds with the micro yield point and the latter with the macro yield point. The “spring limit” or ”Federungsgrenze” is a little larger than this second critical stress. When a specimen is cold-rolled after annealing the internal friction increases and the first critical stress does not increase as the tensile strength. However, after low temperature annealing,the critical stress of a cold-rolled specimen increases remarkably, and this increament increases with the increasing concentration of solute atoms up to the solubility limit. These phenomena are discussed in terms of dislocation model.View full abstractDownload PDF (750K) -
Shuichiro Takahashi1957 Volume 21 Issue 3 Pages 194-198
Published: 1957
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of concentration of solute atoms, cold working, and low temperature annealing on the macro yield point (spring limit or “Federungsgrenze”) of α-copper alloys (Cu-Zn, Cu-Al, Cu-Ni-Zn, Cu-Sn-P alloys) were investigated. The results were as follows: (1) The spring limit of the rolled specimen initially increases with the degree of cold work, and finally reaches a saturation value. (2) After low temperature annealing, however, the spring limit of the specimen rises remarkably and increases continuously with the increasing pre-cold-rolling and with the concentration of solute atoms. (3) This increase of spring limit by low temperature annealing depends upon the density of valence electrons and seems to be not dependent upon the kinds of solute atoms as shown in Fig. 8. This phenomenon is explained qualitatively by the theory of chemical interaction between dislocations and solute atoms proposed by H. Suzuki.View full abstractDownload PDF (732K)
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