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Volume 25, Issue 8
Displaying 1-16 of 16 articles from this issue
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Masataka Sugiyama, Noboru Makino, Hitoshi Shitara1961 Volume 25 Issue 8 Pages 489-493
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAlloys used for essential parts of air-crafts and missiles are often required to have both high strength and high electric conductivity at high temperature in order to stand the severe conditions such as high speed rotation, etc. The copper-zirconium alloys have been spot lighted as new alloys that can cope with such severe conditions. The authors have made a systematical study of the electrical properties and temperature characteristics of these alloys. At first, the effect of zirconium contents to the electrical and mechanical properties of copper-zirconium alloys was studied and then the best conditions for heat treatment were searched. The specimens were at first hot-rolled, and then they were given solution treatment at 800∼850°C, cold-rolled 50∼75% and then aged at 400∼450°C. When the alloy was heated between 100°C and 600°C after solution treatment, a little hardening by aging was observed, but when cold-rolled after solution treatment, fairly remarkable hardening by aging was observed in the case of alloys with minimum 0.1% of zirconium. Consequently, such alloys have high heat resistance and have hardness of no less than VHN 130∼140 and the tensile strength of 60 kg/mm2 after heating at the temperature of up to 400°C. The electrical conductivity was reduced as the content of zirconium increased, but it recovered considerably by aging treatment. For example it recovered to IACS 90% at minimum in the case of alloy containing 0.1% zirconium. On the contrary, the mechanical strength increased as the content of zirconium increased. According to the results of the study on solution-temperatures, the electrical conductivity was reduced as the solution-temperature rose, while the hardness rose to maximum at about 900°C. Taking both factors into consideration, the temperature from 800°C to 850°C is the most suitable. The softening temperature leaped up when the zirconium content went over 0.1% and softening did not begin until the temperature rose above 500°C.View full abstractDownload PDF (468K) -
Kiyokazu Ogawa, Eiichi Takeuchi1961 Volume 25 Issue 8 Pages 494-498
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe experiments were carried out with several lubricating oils of the same group, which were of different viscosities and were separated by reduced pressure distillation. The results obtained were as follows; (1) The reasonable experimental conditions for wear testing were determined by preliminary experiments in which the relations between the contact pressure or the friction velocity and the wear loss were observed. For these experiments hardened bearing steel was used as test specimens in combination with S55C sorbitic carbon steel. The degree of adhesional wear depended on the strength of the oil film formed on the metal surface; when the strength of the oil film increased, the adhesional wear was observed in the higher velocity of pressure region. (2) The efficiency of lubricating oils for the reduction of wear loss depended remarkably on the oil film strength and the coefficient of boundary friction. Experiments under conditions of prolonged mechanical wear also was carried out to verify the above mentioned relation and to compare the lubricating efficiency various lubricating oils.View full abstractDownload PDF (465K) -
Kiyokazu Ogawa, Eiichi Takeuchi1961 Volume 25 Issue 8 Pages 498-501
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn continuation of the preceding paper, the wear of metals lubricated by oil, to which a small amount of fatty acid was added,was observed. The results obtained were as follows; (1) The addition of fatty acids to lubricating oils resulted in a remarkable decrease of the coefficient of boundary friction. (2) Saturated fatty acids decreased the coefficient of boundary friction with increasing oil temperature. In the case of unsaturated fatty acids, however, the maximum coefficient value was obtained at 100°C. (3) Fatty acid improved the lubricating properties of oils used below 50°C. On the other hand, when higher temperatures were used, adhesional wear was observed. Saturated fatty acids were more useful than the unsaturated acids for the improvement of the lubricating properties of oils.View full abstractDownload PDF (470K) -
Mikio Yamamoto, Ryôfu Miyasawa1961 Volume 25 Issue 8 Pages 502-506
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe initial magnetic susceptibility, χ0, has been studied at ordinary temperatures, using the ballistic method, with single crystal and polycrystal rods of iron containing 0.53%Al in thermally demagnetized (TD) state and in alternating-current demagnetized (AD) state. The results of measurements and conclusions obtained are as follows: Either in single crystals or in polycrystal, irrespective of crystal orientation, (χ0)TD>(χ0)AD and, regardless of the method of demagnetization, χ0[100]>χ0[110]>χ0[111] and (χ0)poly>(χ0)single. The measured facts concerning the difference in the method of demagnetization may be explained by an idea of small uniaxal ferromagnetic anisotropies with negative and postive anisotropy constants induced, respectively, by TD and AD, and the observed relation between polycrystal and single crystal data may be interpreted in terms of the magnetic interaction between crystal grains. For both of TD and AD states, the observed anisotropy of χ0 accords well with the formula χ0=χ0[100][2(∑\limitsiβi3⁄∑\limitsiβi)−{∑\limitsiβi3⁄(∑\limitsiβi)2}], which is derived from Brown’s theory of domain wall displacements, for the case where the assembly of 180° domains is present and the relative volumes of domains in unmagnetized state are given by vi0=(1⁄2)(βi⁄∑jβj).View full abstractDownload PDF (399K) -
J\={u}ro Watanabe1961 Volume 25 Issue 8 Pages 506-510
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffects of sulfides on the tensile, notch impact and fatigue properties of twelve samples of 3%Ni-Mo-V steels, having four different sulfur contents and three forging rates, were investigated. The test results were as follows; (i) the decrease of transverse ductility is proportionate to the forging rate and sulfur content; (ii) the effect of small amount of sulfur on the longitudinal notch toughness is remarkable; (iii) the anisotropy of endurance strength increases with the sulfur content, and the transverse strength of the most dirty (0.090%S) steel is 73% of the longitudinal strength; and (iv) no general relationship could be established between the mechanical properties and the inclusion counts by the usual method.View full abstractDownload PDF (388K) -
J\={u}ro Watanabe1961 Volume 25 Issue 8 Pages 510-515
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate the effects of non-metallic inclusions on the strength of steels, the behavior of non-metallic inclusions under tensile stress was studied by microscopic observations and the fatigue properties of several 3%Ni-Mo-V steels made by different processes were tested. The results were as follows: (i) At a slight excess load over the yielding point, microcracks are found at the corners of non-metallic inclusions, especially on the transverse specimen; (ii) between the elongated type inclusions, silicate is more harmful than sulfide to transverse fatigue properties; and this is borne out by the higher strain concentration evident at the silicate during tensile test; (iii) the effect of sulfide on fatigue properties does not exceed 10%, even though the sulfide content is rather high and vacuum-poured electric-arc furnace steel has good cleanliness and good fatigue properties; and (iv) the notched fatigue strength shows little anisotropy.View full abstractDownload PDF (732K) -
Shigeo Owaku, Hideo Akasu1961 Volume 25 Issue 8 Pages 515-519
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn austenitizing diagram representing the austenitizing process in the high frequency-or flame-hardening of carbon steels was obtained. This diagram is provisionally called T-T-A Diagram (Time Temperature-Austenitization Diagram) by the authors. The specimen steels (with C-contents: 0.20, 0.40 and 0.69%) were preliminarily heat-treated to give them various structures: fine pearlite, coarse pearlite and spheroidized cementite. In the experiments, the specimens were heated in a lead bath followed by rapid quenching in the water. Then the T-T-A Diagram was obtained from the change in hardness (Hv). The results were as follows: (1) Under the same pre-heat-treatment with different C-contents, austenitization starts at the same time, but finishes differently that is, the later with the less C-content. (2) Under different pre-heat-treatments with the same C-content, the specimen with a spheroidized cementite structure starts and finishes earliest, followed by one with a fine pearlite and one with a coarse pearlite in that order. (3) In rapid heating and quenching, if the specimen is heated up to the specified temperature, a very short holding time is sufficient for hardening. The spheroidized cementite structure is found effective.View full abstractDownload PDF (1193K) -
Masazo Okamoto, \={O}mi Miyakawa1961 Volume 25 Issue 8 Pages 520-524
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStudies were made on the nitrogen absorption of 20%Cr-Fe alloys containing aluminium up to 4% during heating at high temperatures in pure nitrogen or in air. The results obtained were as follows: (1) As the aluminium content of 20%Cr-Fe alloys was increased, more nitrogen was absorbed during heating in pure nitrogen. (2) When alloys containing aluminum were heated in pure nitrogen, the absorbed nitrogen combines preferentially with aluminium in alloys as AlN. Nitrogen-bearing austenite is not formed until aluminium is consumed as AlN. (3) When nitrogen is absorbed into the alloys containing aluminium, the beneficial effect of it on the resistance to oxidation is significantly deteriorated, and the ductility of such alloys is also reduced considerably. (4) The oxide film preformed on the surface of alloys containing 4% or more aluminium appreciably inhibited the nitrogen absorption in pure nitrogen. (5) In alloys containing 4% or more of aluminium, little amount of nitrogen was absorbed by heating in air due to the formation of the tight film of aluminium oxide. However, in alloys of lower aluminium content, nitrogen was absorbed considerably during prolonged heating in air and the resistance to oxidation as well as to nitrogenization caused by virtue of alloyed aluminium became lost.View full abstractDownload PDF (631K) -
Kichinosuke Hirokawa, Hidehiro Goto1961 Volume 25 Issue 8 Pages 524-527
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSimultaneous determination of chromium and manganese in some low alloy steels and stainless steels was investigated. The background correction method was applied to chromium Kβ line and manganese Kα line. The equation for the correction of background were obtained as follows, XMn=CMn−0.226CCr⁄0.951 and YCr=CCr−0.219CMn⁄0.951. (X,Y…true X-ray intensity, C…observed X-ray intensity). with these equations and calibration curves, chromium and manganese in low alloy steels and 25% chromium-20% nickel steels were determined.View full abstractDownload PDF (258K) -
Yachiyo Kakita, Michiko Namiki1961 Volume 25 Issue 8 Pages 527-530
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAfter dissolving iron-chromium electrical heating alloy sample, most amount of Fe and Cr was separated from the solution by extracting it with methyl isobutyl ketone and then the residual ferric iron in the aqueous phase was reduced to ferrous iron with SnCl2. Co thiocyanate was extracted with methyl isobutyl ketone and the amount of Co was determined by measuring its absorbancy without any influence of small amount of Fe. In the case of nickel-chromium electrical heating alloy, most amount of Cr was volatilized by heating the sample solution to fumes of HClO4. Then, Co and Fe thiocyanates were extracted with methyl isobutyl ketone and simultaneous determination of both elements was carried out photometrically. By this method, 0.5∼0.001% of Co was easily determined. Samples containing over 0.01% of Co and Fe less than a half amount of Co are suitable for simultaneous determination of Co and Fe by this method.View full abstractDownload PDF (337K) -
Takami Maruta1961 Volume 25 Issue 8 Pages 531-535
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influences of various conditions on the aging effects of Cu-Zr binary alloys, such as quenching and aging temperatures, the amount of zirconium as an alloying element and degrees of cold work, have been studied. Zirconium contents of these alloys were in the range of 0.1∼1.0% and the specimens were always melted in vacuum and air. The results are summarised as follows: (1) The higher the quenching temperature is, the better the aging effects are. The quenching temperature in practice lies between 950°C and 970°C. (2) In the aging-treatments for 1 hr at testing temperatures, maximum values of hardness and electrical conductivity apear at 550°C and 600°C respectively. (3) The aging effects are remarkable in alloys cold-worked by more than 60%. (4) The alloys that contain 0.2∼0.3% zirconium have excellent electrical and mechanical properties. (5) The preciptation in Cu-Zr alloys begins at about 550°C and finishes at 650°C or so. (6) These properties are good up to 550°C.View full abstractDownload PDF (396K) -
Michio Arakawa1961 Volume 25 Issue 8 Pages 535-539
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt was attempted, at first,to apply the photometric method with using curcumin for determination of trace amounts of boron in iron and steel, especially heat-resisting steel and alloy. However, the application of the conventional method usually gave fluctuating unstable results because of the unstable nature of alcoholic reagent solution, the adsorption of coloured complex by the dried residue and the continuous variation in atmospheric humidity. Therefore, in the present investigation, the conditions to develop colour with boron by using acetone reagent solution were investigated. Some modifications shown below were adopted. (1) The constant atmospheric humidity surrounding dried residue was maintained throughout the procedure. (2) M.I.B.K. and water were adopted as extractants and sodium hydroxide or sodium carbonate to form soluble salt as fixing agent for boron in order to prevent the turbidity and the decrease in the absorbancy of the coloured complex solution and for the complete recovery of the coloured complex adsorbed by dried residue. (3) In place of the conventional hydrochloric acid+water (1+4) mixture, a hydrochloric acid+ethylacetate (1+2) mixture was used as the accelerator for the development of colour to improve the reliability of the results, to increase the absorbancy of coloured complex and to reduce the duration of evaporation. As a result of these modifications, the reliable results were obtained reproducibly and the conditions to develop the colour for boron were securely established.View full abstractDownload PDF (410K) -
Michio Arakawa1961 Volume 25 Issue 8 Pages 539-543
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFollowing the previous paper, the various conditions required for the quantitative separation of boron from the other components in iron and steel, involved in methyl alcohol distillation and the fixation of boron in the distillate, were investigated. The following results were obtained. (1) The distillate should be kept in a closed vessel, because boron in distillate (as methylester) volatilized propertionaly with the time allowed to contact with flowing atmosphere, even at room temperature. (2) For fixation of boron in the distillate, the concentration of the sodium hydroxide solution should be 0.2 N at minimum, because boron tended to volatilize faster as the concentration of sodium hydroxide solution decreased. (3) A mixture of phoshoric acid and sulphuric acid was an effective solvent for iron and steel samples, especially for those of heat-fesisting steel and alloy, for the preven tion of loss of boron through the foaming of solution when methyl alchol was added. (4) In order to distill boron quantitatively from the mixture of phosphoric acid and sulphuric acid, sufficient cooling of the methyl alcohol vapour containing boron and the distillation until the distillate amounted to 25 mL after the addition of 40 mL of methyl alcohol were required. On the basis of these results and those of the previous paper the photometric method for the determinations of the trace amount of boron was established and satisfactory results were obtained by the application of this method to standard N.B.S. steels and some heat-resisting steels and alloys.View full abstractDownload PDF (410K) -
Shigehiro Inoue, Takashi Tsuchiya1961 Volume 25 Issue 8 Pages 544-548
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffect of C contents on the properties of Ni-Mo-Cr alloys has been investigated by hardness, tensile, microscopic tests and corrosion tests, made with specimens in boiling 10 and 2 wt%HCl for 24 hours. The following results have been obtained: (1) With increasing content of carbon, both the corrosion loss and the hardness of solution-treated Ni-Mo-Cr alloys increased, but the elongation was lowered. This may be attributable to an increase of eutectic carbide (M6C a=11.03 Å), the amount of which increased by addition of carbon. (2) After annealing at 700° and 800°C for 30 min, the higher carbon contents, the more appreciably deteriorated the corrosion resistance due to the continious precipitation of carbide on grain boundaries.View full abstractDownload PDF (702K) -
Shigehiro Inoue, Takashi Tsuchiya1961 Volume 25 Issue 8 Pages 548-551
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffect of V contents on the properties of Ni-Mo alloys has been investigated by hardness, tensile, microscopic tests and corrosion tests, made with specimens in boiling 20 wt%HCl for 24 hours. The following results have been obtained: (1) The corrosion loss and the tensile strength of solution-treated specimens increased lightly with increase of the V contents. (2) The corrosion resistance of Ni-Mo alloys containg 1.5∼3.0%V did not lower after annealing at 700°C for 1 hour, but deteriorated with lengthening the annealing time at 700°C. (3) When high strength and corrosion resistance were required, the most effective conditions were, V content 1.5∼2.0% aged at 850°C for over 25 hr.View full abstractDownload PDF (637K) -
Yoshimi Tanabe, Nobujiro Takamoto1961 Volume 25 Issue 8 Pages 552-556
Published: 1961
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWith an electron microscope, the present authors have studied the behaviour of precipitates in the case of aging of 0.018%C iron and 0.08%C steel at 100°C. In the age-hardening curve, two steps were not observed (Two steps were observed in the case of 70°C aging). The peak appeared at 1 hr aging and the quantity of precipitates was not maximum at this aging time, and the site of maximum quantity of precipitates was appeared at 2 hr aging at which hardness was coming down. From this experimental results and electron microscopic observations, the authors have concluded as follows: (1) The size and the quantity of precipitates have an influence upon the age-hardening curve, but the age-hardening curve was not determined by behaviour of precipitates alone, but probably by the synthetic effects of G.P. zone and the behaviour of precipitates. (2) In the 100°C aging, precipitates appeared comparatively more in ferrite matrix at 2.4 min aging, and precipitates did not appear particularly much along the grain boundary. (3) The size of precipitates was not determined by the aging time alone. That is, each specimen contained precipitates of various size. (4) The precipitates less than about 200 Å have a disk-like shape and those greater than about 200 Å were spherical. The latter grew to platelets of various shape in size of about 2.000 Å. (5) The precipitates were thought to consist of iron carbide.View full abstractDownload PDF (1076K)
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