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Volume 20, Issue 10
Displaying 1-17 of 17 articles from this issue
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Ichiji Obinata, Satoshi Kugasa1956 Volume 20 Issue 10 Pages 533-536
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of titanium on the recrystallization behaviour of cold rolled aluminium as well as aluminium-magnesium alloy has been studied, by mean chiefly of microscopic and X-ray method. An addition of titanium elevates recrystallization-temperatures of aluminium and aluminium-magnesium alloy to the extent of about 50° and makes their grain-size after annealing finer, especially when they are annealed at high temperatures. These effects of titanium, however, are remarkable till the content of titanium reaches 0.1∼0.2%, showing probably the limit of solid solubility of titanium in aluminium. The recrystallized grain-size of Al-1.7% Mg alloy containing more than 0.1% of titanium is fairly fine and almost constant against the change of annealing temperature as well as cold-reduction over 20%. Recrystallization diagrams for Al-Ti and Al-Mg-Ti alloys have been proposed based on the determination of the grain-size after annealing as a function of rolling reduction and temperature of annealing.View full abstractDownload PDF (648K) -
Shiro Terai1956 Volume 20 Issue 10 Pages 536-540
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this report, the influence of hot working on the cast structure of Al and some Al binary alloys refined by addition of small quantity of Ti with or without B was investigated. The results obtained were as follows: (a) The cast grain size grew according to the preheating of ingot before hot rolling, especially in 99.6% Al and Al-2.5% Mg, but the addition of grain refining element reduced the grain growth. (b) As in hot-rolled condition, both preheated and non-preheated materials, the grain size of rolled materials was relative to that of cast one; in other words, grain refining elements for cast structure refined the rolled structure as well as the cast structure. (c) When reheated after hot rolling, the grains were recrystalized and very fine grains were obtained, except in non-preheated Al-1.5% Mn alloy. In this case, the grain refiner for cast structure had less influence on the rolled structure.View full abstractDownload PDF (897K) -
Waichi Ota1956 Volume 20 Issue 10 Pages 540-544
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of low-temperature annealing upon the distribution of hardness and structure and the magnetic properties of cold worked Armco iron were studied. The effects were found influenced by the degree of cold working and different according to the position of transverse section. The changes in the residual stresses, the distribution of hardness and structure and the magnetic properties due to the low-temperature annealing were also discussed.View full abstractDownload PDF (919K) -
Waichi Ota1956 Volume 20 Issue 10 Pages 544-547
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of thermal stress upon the hardness distribution and the mechanical properties of Armco iron, cooled from 850° in three different rates were studied. The hardness was the higher, the larger the thermal stress was. The increase of hardness due to thermal stress was large in the region from the surface to the middle and small in the region from the middle to the central, and the discontinuous step appeared among them. The relationship btweeen the distribution of residual stress and hardness was considered. The effects of external force upon the hardness distribution caused by thermal stress were measured. The changes in mechanical properties were proportional to the degree of thermal stress and its tendency was somewhat similar to that due to light cold working.View full abstractDownload PDF (524K) -
Takashi Araki, Jô Isono1956 Volume 20 Issue 10 Pages 547-550
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe hardness of various Ti-base alloys was measured in high vacuum at temperatures up to 700° for the purpose of finding useful heat-resistant alloys. The results of the measurement are summarized as follows: (1) The hot hardness of annealed alloys increases with increasing Al contents. (2) The hardness of some alloys water-quenched from 900° is shown to be very high. This extraordinary hardness is ascertained to be due to tempering at 500°. Such alloys contain at least 6 pct. Al and 4 pct. Cr (or Cr+Mo). (3) The X-ray diffraction photographs for those temper-hardened alloys show that the β-phase retained in water quenching becomes rich in the content of Cr and Mo by tempering, while they give no evidence of the presence of the ω-phase. Thus it is supposed that the hardening is due to the precipitation of fine α particles from the original β solid solution.View full abstractDownload PDF (536K) -
Hideo Takei1956 Volume 20 Issue 10 Pages 550-553
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe well-known methods to avoid the temper brittleness of Ni-Cr steel are (1) to add Mo to the steel, (2) to cool it rapidly after tempering at the temperature above 600°, avoiding the low tempering temperature ranging from 450° to 575°, or (3) to cool it rapidly after short time tempering at 450∼575°. This experiment is carried out to obtain the practical data on the third method. The results obtained are as follows: (1) At the tempering temperature ranging from 450° to 575°, the shorter the tempering time is the smaller the degree of the first temper brittleness is. So the short time tempering can eliminate the first temper brittleness. (2) If the hardness is taken as the measure of the degree of tempering, the effects of tempering are remarkable at the initial stage. So for the softening of the steel, the tempering time of about 1 hr is enough for ordinary purposes. (3) Accordingly, if Ni-Cr steel is cooled in water after tempering for a time less than 1 hr, both the first and the second temper brittleness are avoidable. (4) Hollomon and Jaffe’s experimental formula on the hardness of tempered steel is also applicable to the steel used in this experiment. (5) The quenching temperature vs. impact value curve shown in this paper, is theoritically equivalent to the equilibrium impact value curve proposed by Greaves and Jones.View full abstractDownload PDF (641K) -
Yûnoshin Imai, Hikotarô Imai1956 Volume 20 Issue 10 Pages 554-558
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFollowing the preceding papers, this paper describes the results of mechanical tests on several samples of the series of 0.15% C, 1.0% Cr, 1.0% Mn, 0.3∼0.7% Si-steels and 0.15% C, 1.0% Cr, 1.0% Mn, 0.3∼0.5% Mo-steels containing boron, tested in normalized or quenched and tempered conditions. In the normalized conditions, the former series did not show any effects of boron-addition, but the latters showed considerably good effects of boron-addition. In the quenched and tempered conditions, the former show the fairly good effects of boron-addition when the amount of Ti was increased to the degree of 0.3% and the content of Si was in the order of 0.3∼0.5%, while the latter the showed the good effects of boron when the amount of Ti added was limitted within 0.2%.View full abstractDownload PDF (684K) -
Takuro Saga, Ohmi Miyakawa1956 Volume 20 Issue 10 Pages 558-562
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe prevention of porosity in hot dipped aluminum coating on the steel sheet is of great importance since in many environments steel is anodic to aluminum and will corrode at an accelerated rate at any discontinuity in the coating. The occurrence of pinholes may be caused either by the character or cleanness of the steel surface, or by factors associated with the aluminum bath. The origins of pinholes to be associated with the aluminum bath have been investigated in this report and the following results are obtained: (1) Among the factors which may lead to pinholes, aluminum oxide on the aluminum bath has a very remarked effect. (2) Aluminum oxide is dissolved gradually with an addition of fluoride (NaF-AlF3 system) to the flux and the great improvement of surface appearance is attained with an addition of about 20% of fluoride. (3) Occurrence of pinholes decreases with the decreasing quantity of aluminum oxide using the same flux in the same quantity. (4) The porosity decreases with an increase of the dipping time. The appearance of the coating is also improved by the shaking of the sheet in the aluminum bath. (5) In the presence of the flux, no accelerated rate of the diffusion of aluminum to the base metal is observed.View full abstractDownload PDF (1025K) -
T. Saga, O. Miyakawa1956 Volume 20 Issue 10 Pages 562-566
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe origins of pinholes due to the uncleanness of the steel surface have been studied in this report and the following results are obtained: (1) Oil on the steel surface, though in a small quantity, is a dominant factor of the occurrence of pinholes. (2) The cause of pinholes is also to be sought in the presence of iron oxides on the surface. Moreover, the adherent molten aluminum does not run uniformly from the surface, but contracts into drops. (3) Carbon deposited on the surface prevents remarkably the reaction between the molten aluminum and the steel. (4) The reaction product of the pickling process may be only of secondary importance as the cause of pinholes. (5) A great improvement in the appearance is obtained by an employment of the hot dipping process in which the sheet is preheated in the molten flux and then dipped into the aluminum bath.View full abstractDownload PDF (896K) -
Satoru Mito1956 Volume 20 Issue 10 Pages 566-569
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFernico alloys are now being used for glass sealing because of its low expansion coefficient fitted to hard glasses. These alloys transform from γ to α phase at low temperature on cooling. Sometimes glasses are broken after sealing by the stress induced with the martensitic transformation of Fernico at near room temperature. In this experiment the effects of heat treatments on the suppressing of the transformation of Fernico were examined. The results obtained are as follows: (1) The transformation processes in Fernico are considered as the same as in Fe-Ni binary system which consist of transformation by diffusion at high temperature and of martensitic transformation at low temperature. (2) By annealing at γ+α region after cold working, the transformation point falls remarkably as compared with normal high temperature treatment. (3) The expansion coefficient of the specimen annealed at γ+α region does not so differ from normal that of a specimen. Thus such a heat treatment may be useful for glass sealing with Fernico.View full abstractDownload PDF (610K) -
Satoru Mito1956 Volume 20 Issue 10 Pages 569-573
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPure nickel is used in vacuum tubes as lead wires. In the stem making process or glass sealing processes, they often become brittle by heating in city gas. This brittlness is generally considered as an effect of impurities included in nickel. In this experiment the brittleness of several specimen wires, namely, Inco nickel, Mond Nickel, Falconbridge nickel, Driver Harris nickel and Domestic nickel wires were examined and it was clarified that the brittleness observed in these specimens are due to micro cracks formed along the grain boundaries by the gas attack. When heated in a gas purified through a NaOH and P2O5 tower and a hot copper furnace, the brittleness was not observed. An addition of some alloying elements, i,e, Mg, Si, Cr, Ti, Al and Mn was found very useful for the prevention of brittle fracture in pure nickel.View full abstractDownload PDF (661K) -
Yoshiaki Miura1956 Volume 20 Issue 10 Pages 573-576
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe rapid polarographic determination of lead in brass and bronze was carried out as follows: After the sample was dissolved in aqua regia, the solution was boiled with excess sodium hydroxide solution and diluted to a definite volume. Then, lead in the supernatant solution was determined polarographically. If the solution was filtered, lead was partially absorbed on the filter paper, and the result was not well reproducible, so the sample and the calibration solutions should be taken from the supernatant solution. The presence of iron, aluminium and manganese over about 0.5% caused interferences.View full abstractDownload PDF (536K) -
Yoshiaki Miura1956 Volume 20 Issue 10 Pages 576-578
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe sample was dissolved in hydrochloric and nitric acid mixture and tin was separeted as hydroxide in an ammoniacal ammonium chloride medium. Then, the precipitated hydroxides were dissolved in hydrochloric acid and tin was determined polarographically in 1 mol hydrochloric acid-4 mol ammonium chloride solution. As lead in samples was partially coprecipitated with tin and the lead wave overlapped the second tin wave, the coprecipitated lead was estimated separately in an ammoniacal tartarate medium and subtracted.View full abstractDownload PDF (370K) -
Hisato Hagiwara1956 Volume 20 Issue 10 Pages 579-582
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFrom the metallurgical and practical viewpoints, removal of copper from Pb-Cu alloy is one of the important reaction in lead refining process. Concerning this, the author measured directly the equilibrium constant of equation (A) using a porcelain crucible in evacuated quartz tube at the temperature range from 420° to 800°. Cu2S(S)+Pb(l) \ ightleftarrows2Cu(in l-Pb) +PbS(s)............ \ agA When the two phases of Cu2S and PbS exist in the melt, the equilibrium constant for the reaction (A) is expressed as follows: logK_Cu = log[% Cu]^2 From the experimental results, the following equation is obtained as the temperature function of the equilibrium constant. logK_Cu = -2910.4/T+2.280; ΔF° = 13.301-10.420 T When the melt is saturated with Cu2S and PbS remains in the melt, the equilibrium constant for the reaction (A) is expressed as follows: logK_Cu-S = log[% Cu]^2 [% S] From the experimental results, the next relation is also obtained. logK_Cu-S = -4442.8/T+3.378; ΔF°=20.304-15.44 T Further, the saturated value of % Cu can be calculated by combining the free energy change of the next three equations. Cu2S (S) + H2 \ ightleftarrowsH2S + 2 Cu (s)
PbS(S) + H2 \ ightleftarrowsH2S + Pb(l)
Cu(S) \ ightleftarrowsCu(in 1-Pb) Comparison of these calculated values with the experimental values shows comparatively good agreement.View full abstractDownload PDF (512K) -
Hisato Hagiwara1956 Volume 20 Issue 10 Pages 582-584
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe chemical activity of sulphur in liquid lead containing element X (either Ag, Cu, Bi or Sb) was measured by means of the reaction formula. S(in liq. Pb containing X) + H2=H2S at the temperature range of 800∼900°. From the results obtained, it was concluded that the activity coefficient of sulphur in liquid lead increases with Ag, Sb and Bi content, and was lowered with Cu content. The effect of coexistence of Sb and Bi was also measured.View full abstractDownload PDF (392K) -
Tsuneo Satow, Sukeji Kachi, Keizô Iwase1956 Volume 20 Issue 10 Pages 584-588
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe thermodynamic properties of γ, α and the superlattice phase of iron-cobalt alloys were derived from equilibrium measurements between H2O, H2 and alloys of various compositions. In the field of γ phase, the entropy of mixing and the heat of mixing showed almost ideal behaviors, and the activity obeyed Raoult’s law. In the α phase, the activity showed negative deviation from Raoult’s line, the heat of mixing was negative (ΔHmax=−1.9 kcal/g·atom at 740°), and the excess entropy showed a large negative value. It is considered that this anomalous entropy shows an inapplicability of Neumann-Kopp’s law for this alloy system, which may be seen also clearly in the fact that curie temperatures of alloys are different from that of pure iron. The effect of superlattice FeCo. formation was found in the ‾ΔG vs. temp. diagram, that is, the sign of the partial molar configurational entropies for 49.7 at% and 51.9 at% were found to be inverse, and whose numerical value showed a good agreement with the calculated value. The heat of α-γ transformation at 50 at% was derived from the difference of ΔH for above and below the transition temperature.View full abstractDownload PDF (711K) -
Hideo Nishimura, Hirozo Kimura1956 Volume 20 Issue 10 Pages 589-592
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe equilibrium diagram of the binary systems, titanium-oxygen and titanium-carbon have been thoroughly investigated by the present authors. Following these investigations, the ternary equiliblium diagram of titanium-oxygen-carbon system has been studied similarly. In this ternary system, there exist the following solid phases; α-titanium, β-titanium, carbon, δ(TiC-TiO), ε(Ti2O3), and η(TiO2).
The α-phase containing about 10% oxygen dissolves about 1.5% of carbon as its solid solution, and the β-phase is considered to be produced at the titanium rich side of this ternary system by a ternary peritectic reaction; Liquid+δ(TiC-TiO)+α(Ti,O,C)\ ightleftarrowsβ(Ti,O,C) and the β-phase exists at the temperature higher than the transformation temperature α\ ightleftarrowsβ of titanium at 885°. The δ-phase is a continuous solid solution of NaCl type cubic stracture, and existing in the wide range of composition between TiC(δ) phase in the titanium-carbon binary system and TiO(δ) phase in the titanium-oxygen binary system. In this ternary system, three invariant reactions containing gaseous phases as; & Liquid + Graphite \ ightleftarrowsδ Phase + Vapour at about 3000°
& Liquid + ε phase \ ightleftarrowsδ phase + Vapour at about 1800°
& Liquid \ ightleftarrowsη phase + δ phase + Vapour at about 1670° are considered to exist.View full abstractDownload PDF (670K)
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