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Volume 23, Issue 3
Displaying 1-16 of 16 articles from this issue
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Sigeru Yonetani1959 Volume 23 Issue 3 Pages 137-141
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSLow-carbon steel of the composition of C 0.13∼0.2%, Mn 0.7∼2%, is used for large-size chains. It is sometimes quenched and tempered, after welding, for the purpose of increasing its strength. Because of the low content of C, this sort of steels in such a structure, is not completely martensitized. Its mechanical property is influenced to a large extent in the cooling state, according to the quenching method. At the same time it is affected by the mode of heat treatment, that is pre-treatment, heating temperature and heating time in the quenching. These are very important affairs in the practical production. Nevertheless these seem to be neglected and the studies on the quenching of this sort of structure are very rare. This experiment first intend to describe the state how the mechanical properties of this sort of steel are changed by heat treatment.This is considered in relation to the growth of γ grains in the austenite region. Then follows an inspection of the tendency of the ferrite precipitation in the cooling process from the various heating conditions being expressed as the functions of temperature and time. We come to the conclusion that, the rate of ferrite precipitation at the subcritical temperature and its hardness after quenching is closely related with the state of Al, N and AlN which are dissolved or precipitated in the γ region.View full abstractDownload PDF (749K) -
Tadashi Kawasaki, Hisashi Izumi, Tadakazu Sakurai1959 Volume 23 Issue 3 Pages 141-144
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt was confirmed in the previous papers that the static strength of mild steel was markedly improved by stress-aging (strain-aging under a stress), because the stress imposed on the specimen during strain-aging may accelerate the aging phenomena. A further study was made to examine the effect of stress on the process of strain-aging of mild steel. Specimens (0.05%C mild steel) were strained to 9% in tension and then aged under tensile stresses at various temperatures, from 55°C up to 250°C. The results obtained are as follows: (1) It is sure that strain-aging of mild steel is accelerated by stress imposed on the specimen. (2) The maximum increase of hardness caused by strain-aging increases, and time when the hardness reaches its maximum value decreases with the increase of stress imposed on the specimen. (3) The activation energy for the process of strain agang is unaltered whether a stress is applied or not during strain-aging, so that the main process of strain-aging under stresses seems to be the same in itself as that of conventional strain-aging.View full abstractDownload PDF (683K) -
Makoto Osawa1959 Volume 23 Issue 3 Pages 145-149
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe mean lengths of ferrite grains and pearlite colonies were measured quantitatively under a microscope, in the main direction of rolling in cold-rolled low-carbon steel sheets. These mean values measured were always smaller than the values estimated from the external shapes of the sheets. This means that the mean deformation of the grains and the colonies was not similar to that of the shape of the sheet. From this result, we conclude that the pearlite colonies and the ferrite grains were split into smaller ones by cold-rolling. This split of a ferrite grain was always larger than that of a pearlite colony, for example, at 53.1% reduction of thickness a grain and a colony split into 3.8 grains and 2.4 colonies on the average, respectively.View full abstractDownload PDF (785K) -
Makoto Osawa1959 Volume 23 Issue 3 Pages 149-152
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe quantitative measurments, as previous by reported, were performed on pearlite colonies and ferrite grain of cold-rolled low-carbon steel sheets. The observed mean distances between the pearlite colonies were greately different from the values estimated from the changes of the external dimension of the specimen. The degree of elongation (ratio of the mean length in the direction of rolling to that of the thickness) of the ferrite grains and the pearlite colonies was also different from the estimated value. Between the logarithms of the degree of elongation and the hardness of ferrite and pearlite a linear relation was observed.View full abstractDownload PDF (631K) -
Masao Ikeda1959 Volume 23 Issue 3 Pages 152-156
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy studing the reduction of MgO·CaO by Fe-Si, the following results were obtained. (1) The yield of magnesium increases with temperature and the activation energy is found to be 55,000 cal/mol. (2) The amount of magnesium produced per unit charge shows a maximum at about mol ratio MgO/Si=1. (3) The addition of CaO increases the yield of magnesium and of Al2O3 or Fe2O3 decreases it. (4) By X-ray diffraction method, not only 2CaO·SiO2 but also 3CaO·2SiO2 were found in the residue produced in the reduction of MgO-CaO by Fe-Si. (5) There is not a great difference between Fe-Si and Ca-Si reduction in yield of magnesium and activation energy, but the cost of the reducing material Ca-Si is about 1.4 times as high as that of Fe-Si.View full abstractDownload PDF (598K) -
Yûnoshin Imai, Masao Izumiyama1959 Volume 23 Issue 3 Pages 156-160
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe stabilization of retained austenite after partial transformation to martensite has been investigated using 1.12%C, 4.98%Ni steel. The stabilization degree was expressed by the temperature lag θ of transformation point or the stabilized austenite %δ. It was observed that the temperature lag θ is a function of aging time. In this steel, the following empirical equation expresses the relation between θ and aging time at room temperature: θ=52−48t−0.34 where θ is the temperature lag in centigrade degrees and t is the aging time in minute. It has been found that the recovery of martensite transformation occurred during subsequent cooling after aging in the early stage of stabilization, but did not occur in the last stage of it. Accordingly the correlation between θ and δ is not a linear relation. The stabilization proceeds very rapidly when the previously transformed martensite increases to more than 65%.View full abstractDownload PDF (659K) -
Kazuo Ota1959 Volume 23 Issue 3 Pages 160-164
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBricker’s double extraction method for determination of Zn in steel was modified and simplified by studing the conditions of extracting and washing the zinc dithizonate. Extracting the Zn for once with 25 mL of benzene solution of 0.01% dithizone for 2 minutes and washing the extracting layer 6 times with 10 mL of 0.05%Na2S is the most suitable condition for the determination of Zn. The use of benzene as the solvent of dithizone has more advantages for Zn as well as Pb than that of CHCl3 or CCl4, for with the former a single extraction is effective enough and the washing is easy, etc. The color of zinc dithizonate is stable for at least 4 days. Other elements in cast iron or carbon steel do not interfere except over 0.4% of Cu. The proposed method is suitable for the determination of 0.0002∼0.04% of Zn contained in cast iron and carbon steel.View full abstractDownload PDF (635K) -
Toshinori Kuroda, Haruki Kondo1959 Volume 23 Issue 3 Pages 164-168
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA trial electrolytic hardening machine of dipping type of 20 kW capacity was constructed with special regard to equality of heating and modulation of quenching speed. Equality of heating was accomplished by generating electric arc at the surface of the cathode immediately after dipping it into the solution. For that purpose a gas burner was provided and the work was heated to about 200°C before being heated electrolytically. The quenching speed was changed by either dropping or standing still the work in the solution, by varying the time in which the work is being cooled in the solution,or by changing the voltage between the terminals to which the heating voltage is switched down when the heating is over and at which the work is cooled gently in the solution. The last quenching process was studied qualitatively by analysing the voltage-current curve in the case of electrolytic heating, and the availability was comfirmed by experiments. Machine saws, plus screw drivers, and rings of travellers were satisfactorily hardened electrolytically by this machine. The circuit diagram of the machine and the conditions and the results of the hardening are given in the text.View full abstractDownload PDF (707K) -
Yoshiro Hori, Ikuzo Uezawa1959 Volume 23 Issue 3 Pages 168-172
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of ultrasonic waves during solidification of melt on the structure of Al-Si alloys was studied with a 28 kC magnetostrictive vibrator. The results obtained were as follows: (1) In the hypereutectic alloys ultrasonic waves seem to favor the separation of Si primary crystals, and in the hypereutectic alloys they effectively serve in forming primary crystals finer than without the treatment. (2) The crystal refinement is independent on the rate of solidification. (3) The crystal refinement is not proportional to the vibrational intensity. Below a certain intensity value, no additional crystal refinement is observed. (4) The mechanism of the refinement seems to be due not only to the breaking of crystals by frictional force of the vibrated melt, but also to a direct effect of ultrasonic waves on their nucleation.View full abstractDownload PDF (1198K) -
Ryoichi Nozato1959 Volume 23 Issue 3 Pages 173-177
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe aging process of 10%Sn-Pb alloy at 50°, 75°, 100° and 110° was studied by tracing the specific heat- versus-temperature curves. (1) At a temperature lower than about 112°, the precipitation of tin from lead takes place in two stages. At a higher temperature than about 112°, the precipitation of tin seems to be completed in one stage. (2) The kinetic law for the 2nd stage of the precipitation seems to be represented as follows; p=Ktn+C, where n is a constant independent of temperature and has the value of about 0.5. The activation energy for the 2nd stage was obtained from the relation between the rate constant K and the aging temperature T. The activation energy for the 2nd stage obtained in this investigation is ca. 18 kcal/mol and is in fair agreement with the earlier estimation of the activation energy for the 2nd stage obtained from the micro-hardness measurements, ca. 22 kcal/mol. These values of the activation energy for the 2nd stage are appreciably different from the activation energy for the 1st stage, ca. 9 kcal/mol.View full abstractDownload PDF (747K) -
Mutsuo Ohta1959 Volume 23 Issue 3 Pages 177-181
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe deformation parameter k(=Ra⁄Ra, Ra: radius of ellipsoid of deformed zones parallel to the rolling direction, Rb: radius parallel to the rolling plane and perpendicular to the rolling direction) of various size of zones, which were formed in the quenched Al-30 wt%Ag alloy under different annealing conditions, were measured by the X-ray small-angle-scattering effects. The following results was obtained: (1) When the reduction of thickness by cold-rolling was 50%, the values of k were 1.6∼1.2 for all specimens, on the other hand, the deformation parameter k′ for crystal grains was 2.20∼1.94. (2) When the reduction of thickness was the same as (1), the values of k for the specimens annealed at the reversion temperatures (190° and 210°) and cold-rolled were about 1.5, and the values of k for specimens annealed at the temperature of low-temperature aging (110°, 130° and 150°) and cold-rolled did not exceed 1.35. (3) These facts show that the zones formed by low-temperature aging are more difficult to deform, and that the zones must be one of the main causes of low-temperature age-hardening. (4) The sizes of zones do not affect the deformability of the zones.View full abstractDownload PDF (699K) -
Toshio Doi1959 Volume 23 Issue 3 Pages 181-184
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNickel alloy ingots containing aluminum up to 6% and titanium up to 7.5% respectively, were made by vacuum melting. The alloy ingots were made into 1 mm dia. and 0.5 mm dia. wires by forging and drawing. The changes in tensile strength, elongation and grain size by annealing, the tensile strength at elevated temperature, the anti-corrosion and the anti-oxidation properties were measured. It was disclosed that the tensile strength at moderate temperature of Ni-6%Al alloy and Ni-7.5%Ti alloy was larger than that of special steels and the tensile strength at elevated temperature of these alloys was larger than that of tungsten and molybdenum. The difference between the atomic radii of nickel atom and titanium atom being larger than that between the radii of nickel atom and aluminum atom, titanium addition to nickel was more effective for increasing the strength than aluminum addition. The larger the aluminum content, the slightly larger the anti-corrosion and the anti-oxidation properties, but a special behaviour was disclosed by Ni-4.5%Al alloy, namely that its anti-corrosion and anti-oxidation properties were very small. On the otherhand, the larger the titanium content, the slightly smaller the anti-corrosion property and the slightly larger the anti-oxidation property.View full abstractDownload PDF (639K) -
Susumu Morioka, Akimi Umezono1959 Volume 23 Issue 3 Pages 185-189
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of halogen ions on the anodic passivation of titanium in acid, neutral and alkaline solutions has been studied. The results show that: (1) In the presence of F−, severe attack of titanium occurs in an acid solution due to the chemical dissolution of the oxide film by undissociated HF. However, in neutral and alkaline solutions titanium is not attacked. (2) Cl− does not prevent the passivation of titanium due to a very high discharge overvoltage on titanium. (3) Br− discharges from acid and neutral solutions with high overvoltage, giving a pitting corrosion in a neutral solution. (4) I− also shows high overvoltage discharges in acid and neutral solutions but not in an alkaline solution below the discharge potential of OH−. No pitting corrosion occurs by the discharge of I−, since the discharging points tend to spread all-over and to disperse the electrolytic current. The corrosion resistivity of titanium in halogen-bearing solutions is due to its larger affinity with oxygen than with halogen. Therefore, in aqueous solutions the amount of dissolved oxygen, OH− ion, or oxidizing agent has a significant effect on the corrosion resistivity of titanium. No pitting corrosion takes place unless a considerable external electrolytic current is applied, and in the natural environment corrosion is usually prevented.View full abstractDownload PDF (825K) -
The Solubility of Zr in Molten Mg. (On Al, Fe, Mn and Si as Impurities in Mg-Zr Alloys (1st Report))Riei Ichikawa1959 Volume 23 Issue 3 Pages 189-191
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe grain-refining effect of Zr on magnesium is caused by Zr which is soluble in molten magnesium and Al, Fe, Mn and Si as impurities have unfavorable effects on this grain refining by making insoluble compounds with Zr. The grain-refining effects of Zr on magnesium containing the unfavorable elements above depend on the amounts of Zr and Al, Fe, Mn and Si which are soluble in molten magnesium together. Upon researches on the relation between Zr and Al, Fe, Mn and Si which are solubl in magnesium together at 700° and 800° the results obtained were follows: The solubility of Zr in magnesium was drastically decreased by presence of Al, Fe, Mn and Si The limits of the solubility in these cases were determined. When Zn was contained as alloying elements, the solubility of Zr in magnesium containing Al, Fe, Mn and Si was not so much decreased as in the case without Zn. The liquidus of the phase diagrams of Mg-Al-Zr, Mg-Fe-Zr, Mg-Mn-Zr, Mg-Si-Zr and Mg-Zn-Zr systems at Mg corners at 700° and 800° were obtained.View full abstractDownload PDF (470K) -
Riei Ichikawa1959 Volume 23 Issue 3 Pages 192-194
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen Zr and unfavorable elements such as Al, Fe, Mn and Si over the solubility limits are present in molten magnesium, Zr and these elements make intermetallic compounds. Components of these compounds were investigated. and binary compounds such as Al3Zr in Mg-Al-Zr, Fe2Zr in Mg-Fe-Zr, Mg2Zr in Mg-Mn-Zr and SiZr2 in Mg-Si-Zr were found to exist,unconpounded metallic Zr was contained when alloying Zr over the solubility limit in molten Mg-Zr, Mg-Zn-Zr alloys.View full abstractDownload PDF (423K) -
Masao Terasawa1959 Volume 23 Issue 3 Pages 194-198
Published: 1959
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe author systematically studied lead-silicon and lead-antimony-silicon alloys for explanation of their corrosion resistances to the flash test by H2SO4, and H2SO4, HCl and (NH4)2SO4 solutions. The experimental results were as follows: (1) In respect of the flash point, lead-silicon alloys were generally less resistant than lead, and lead, and lead-antimony-silicon alloys were superior to lead-antimony alloys. (2) The corrosion rate of lead-silicon alloys was remarkably changed in the range of 0.008∼0.017% of silicon contents reqardless of concentrations and temperatures of the used acid solutions, and this tendency corresponded with the mechanical properties of these alloys. In H2SO4 solutions, the corrosion resistance was improved generally. In HCl solutions, the resistance was improved in proportion to silicon contents, and in (NH4)2SO4 solution, the corrosion rate showed almost a constant value in spite of silicon contents. (3) The corrosion rate of lead-antimony-silicon alloys was remarkably changed in the range of 1% and less of antimony contents for each concentration and temperature of the used acid solutions, and its tendency corresponded with their mechanical propreties. In H2SO4 at 30° and 75°C. lead-antimony-silicon alloys showed better resistance than lead-antimony alloys, and in HCl and (NH4)2SO4, these ternaly alloys were improved in proportion to antimony contents in respect of corrosion resistance.View full abstractDownload PDF (568K)
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