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Volume 20, Issue 5
Displaying 1-16 of 16 articles from this issue
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Tomo-o Sato, Saburo Toya1956 Volume 20 Issue 5 Pages 239-243
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the 1st report, the standard composition of graphitic steel was determined as 1.5% C and 1.0∼1.5% Si, but its graphitizing characteristics may be changed by adding other alloying elements to it. Therefore, the experimental researches were carried out on the forgeability of an ingot and the graphitization, the change of hardness and the micro-structured of the standard composition graphitic steel containing 0.4∼2.1% W, 0.09∼0.73% Mo, 0.10∼1.02% Cr and 0.51∼1.37% Ni separately, by annealing the samples at various temperatures. With an increase of the content of W, Mo and Cr in the graphitic steels the forgeability of them were improved, while addition of Ni made it poor. The power of graphitization in graphitic steel, just as in cast iron, was retarded slightly by W and Mo and strongly by Cr, and accelerated by Ni. The suitable composition of graphitic steels containing special elements separately was determined as follows; about 2.5% W, 1.5% Mo, 2% Ni and under 0.3% Cr (1.5% C and 1.5% Si being common to all).View full abstractDownload PDF (1175K) -
Tadashi Nemoto1956 Volume 20 Issue 5 Pages 243-247
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe hardenability of four kinds of low alloy steels, containing 0.5% Mo, 1.0% Cr 0.5% Mo, 1.0% Cr 1.0% Mo and 2% Cr 1.0% Mo, respectively, was investigated by the Jominy test and dilatometric method, together with the measurement of hardness and the observation of their microstructure. Then the relation between the cooling rate in quenching and the amount of retained austenite was clarified through magnetic analysis for studying the anomaly in hardenability curves. The results of these experiments are summarized as follows: (1) The quenching diagrams for each of the above mentioned steels were determined. (2) The hardenablity increases with the increase of Cr and Mo. (3) The transformation ratein Ar′ nose is larger than that in Ar1 nose. (4) The amount of retained austenite is maximum in the range of cooling rate where abnormal shapes appear in Jominy hardenability curves. (5) Two separate Ar″ transformation temperature curves are given in the diagram for each steel, one at rapid cooling and the other at slow cooling.View full abstractDownload PDF (1000K) -
Tatsuo Fujiwara1956 Volume 20 Issue 5 Pages 247-251
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDisk-like specimens and press mandrels made of 0.35% C, 5% Cr, 1.5% Mo, 1% Si hot-die steel were examined. The specimens were heated and cooled repeatedly by an induction surface hardening apparatus, and the mandrels were used for hot-pressing 0.3% C carbon steel. The formation and the propagation of the heat-checks was studied, and the results obtaind are as follows: (1) The formation of the heat-checks is affected by inter-granular oxidation of the surface in heat treated state. (2) The depth and the width of the checks distribute in exponential formula. (3) The heat-checks propagate gradually to the core and the distribution coefficient decreases in response to repetition of the heating and cooling cycle. (4) The heat-checks propagate mainly about the boundaries of the primary crystals.View full abstractDownload PDF (936K) -
Ryohei Tanaka1956 Volume 20 Issue 5 Pages 251-255
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSStatic bending test was used to evaluate the toughness of the bearing steel SUJ 2. The results obtained are as follows: (1) Both in oil-quenching and marquenching, maximum hardness was obtained after austenitizing at 900° for 5 min, whereas the toughness decreases remarkably with higher temperature of austenitizing, and above 900° the superiority of marquenching in increasing the toughness diminishes. (2) It is desirable from the effect on toughness that austenitizing time should be as short as possible. (3) Subzero-treatment increases the hardness but reduces the toughness of hardened steel. (4) Oil-quenching and marquenching with or without subzero-treatment followed by tempering up to 200° were compared in their effect on toughness and hardness of heat-treated steels, and it was found that on the hardness level of Rc 59∼61 of these methods, the best properties were obtained by marquenching after austenitizing of 830° 5 mm with or without subzero-treatment followed by tempering, and on the hardness level of Rc 61∼64, by marquenching after austenitizing of 830° 5 min or 860° 5 min followed by tempering.View full abstractDownload PDF (597K) -
Ôhiko Kammori1956 Volume 20 Issue 5 Pages 255-258
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe author studied the photometric method for the determination of small amounts of chromium and nickel in iron and steel and found the following most suitable: Cr; Dissolve a sample in a mixture of HNO3, H2SO4 and H3PO4, add KMnO4, reduce the excess of KMnO4 with urea and NaNO2, add diphenylcarbazide, add HF to prevent the interference of Fe+++ and measure the extinction. This method requires only 12 to 13 minutes and is applicable to iron and steel containing 0.005 to 0.78% of Cr. Ni; Dissolve a sample in HNO3 and HClO4, evaporate to fume, cool, add water to dissolve salts, dilute to 250 mL, take 25 mL of the supernatant liquid into a measuring flask of 100 mL, add citric acid and NH4OH, mix well, cool, then add I2 and dimethylglyoxime NaOH solution, dilute to the mark and measure the extinction. The time for analysis is only 10 to 12 minutes and 0.001 to 0.7% of Ni can be determined by this method.View full abstractDownload PDF (686K) -
Ôhiko Kammori1956 Volume 20 Issue 5 Pages 258-262
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe author studied the photometric methods for rapid and accurate determination of small amounts of vanadium in iron and steel and obtained good results by the following procedure: when vanadium content is more than 0.1%, dissolve the sample in perchloric acid and nitric acid evaporate to fume, add hydrogen peroxide, add hydrofluoric acid to eliminate the interference of titanium and measure the extinction. This method requires about ten minutes, and Cr up to about 0.7%, Ni up to about 5%, W up to about 0.6%, and Mo up to about 0.5% were found to have no influence. In the presence of 0.001 to 0.07% vanadium, dissolve the sample in sulphuric acid and hydrogen peroxide, expel the hydrogen peroxide by boiling, add potassium permanganate to decompose the carbide, reduce the excess of permanganate with hydrogen peroxide, boil off hydrogen peroxide, cool to the room temperature, oxidize vanadyl ion to vanadate with potassium permanganate, reduce the excess of permanganate with urea and sodium nitrite, add sulphuric acid and phosphoric acid, add diphenylamine at about 40°, mix well, dilute, and measure the extinction. This method requires only twelve to thirteen minutes and W up to about 0.1% was found to have no influence.View full abstractDownload PDF (746K) -
Shigeo Wakamatsu1956 Volume 20 Issue 5 Pages 262-265
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe most generally used methods of determining alumina in steel are those in which the sample is dissolved in an inorganic acid. Virtually all of the inorganic acids have been used to dissolve steel and isolate alumina, but of the many acids sulfuric acid is most widely used. Alumina was separated from the metal with a 10% aqueous solution of sulfuric acid and 15% hydrogen peroxide and carbonaceous materials and aluminium nitride was destroyed by oxidation with potassium parmanganate. It appears that alumina are sufficiently stable so that dilute sulfuric acid is not critical. The residues have been recovered by filtration and analyzed by aluminium quinolate method. The method is admirably suitable for routine work.View full abstractDownload PDF (637K) -
Hideo Takaki, Masashige Koyama, Hidekiyo Fujihira1956 Volume 20 Issue 5 Pages 266-269
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn examination was performed microscopically with single crystals of 99.995% pure tin in order to clarify the relation between the purity and the direction of formation of “corrugations” and “partial dendrites” which had been observed in single crystals of tin grown from the melt. It has been found that the directions of corrugations and partial dendrites deviate from the direction of easy growth, [110], towards that of heat flow more than in single crystals of 99.87% pure tin studied in the previous reports. On the free top surface of the specimens grown in the [110] and [100] directions, an appearance similar to the step structure recently reported by Elbaum et al. was observed.View full abstractDownload PDF (939K) -
Mikio Yamamoto, Jirô Watanabé1956 Volume 20 Issue 5 Pages 270-274
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe light figures revealed and crystal planes developed by etching in single crystals of copper and α-brass have been studied and the suitability of the observed light figures for determining orientation has been examimed. Distinct {100}, {110} and {111} light figures, suitable for orientation determination, are produced in copper and its all alloy crystals etched with 20% (NH4)2S2O8 solution and in alloy crystals containing more than about 20%Zn etched with 50% aqua regia, with 1:1 mixture of cone. HCl and sat. FeCl3·6H2O solution, or with 99:1 mixture of 50% H2SO4 and K2Cr2O7. It has been found that crystal faces developed by etching vary systematically with the etching condition and the composition of the crystals.View full abstractDownload PDF (1025K) -
Seiichi Karashima1956 Volume 20 Issue 5 Pages 274-277
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the extension test of an aluminium single crystal plate whose primary slip direction lies in the direction of its width, it happens that the primary slips occur only in the regions near its side surface and that the greater part of its top surface is covered by unpredicted slips. This singularity is attributed to the relief process of the bending stresses induced by primary slips, and this view is verified by the extension tests with supplementary bending moments and by the uniform bending test.View full abstractDownload PDF (675K) -
Yasuji Kawai1956 Volume 20 Issue 5 Pages 277-281
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influence of silicon and manganese on the rate of sulphur transfer across a slag-metal interface has been studied at a temperature range from 1490 to 1560° in graphite crucibles. The experimental method was the same as in the previous report. The rate of sulphur-transfer from metal to slag increases with increasing silicon and manganese in metal, while that from slag to metal does not change appreciably. Therefore, the rate of desulphurization of molten iron by slag increases with increasing silicon and manganese. The consideration of sulphur activity does not account for the increase of the rate of desulphurization. The mechanism of sulphur transfer and the influence of silicon and manganese are discussed.View full abstractDownload PDF (640K) -
Seita Sakui, Kimiko Sato1956 Volume 20 Issue 5 Pages 281-285
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSpecimens of thin aluminum wires or foils were quenched in very short time of 0.01∼0.04 seconds after the completion of hot working, thus preventing the recrystallization after hot working. Thin wires of aluminum single crystals were also tested in the same manner. We investigated those specimens with X-ray taking Debye-Scherrer rings or Laue spots by Kα-lines of copper. The Debye-Scherrer rings showed remarkable internal stress and grain fragmentation, comparable to those of cold-worked specimens. Evidences of polygonization were found on both the polycrystalline specimens and single crystals, when elongated at very high temperatures. The sign of conventional recrystallization was not found in any of the specimens tested.View full abstractDownload PDF (589K) -
Masazo Okamoto, Ryohei Tanaka1956 Volume 20 Issue 5 Pages 285-288
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy measuring the differential dilatation at subzero-temperature between an oil-hardened high speed steel and an annealed steel specimens, it was concluded that martensite both as isothermal and athermal components is formed over a range of temperature on cooling, the existence of the former component being demonstrated by isothermal holding, and that during subsequent heating from −196° to room temperature after the cooling from the temperature of is othermal holding, an abnormal dilatation corresponding to the isothermal component takes place over the temperature range from −125° to −50°. The dilatation curves showed that the amount of transformation during isothermal holding on subzero-cooling increases with a lowering of the isothermal holding temperature “t”, passes through a maximum at a certain temperature, which is dependent upon aging time prior to subzero-cooling after oil-quenching, and then falls to nearly zero at t below −150°. On the other hand, the amount of abnormal dilatation in subsequent heating diminishes with a lowering of t of prior holding, reaches a minimum at t=−90°, independent of the aging time prior to subzero-cooling, and then increases with further lowering of t.View full abstractDownload PDF (621K) -
Tadayuki Nakayama1956 Volume 20 Issue 5 Pages 288-291
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present authors studied, by electron diffraction, the surface layers of 13-Cr, 25-Cr, 18-8 and high Mo (approximate 7% of Mo) stainless steels attacked by atomosphere containing NH3 gas and a little amount of air at 700°, and thereby explained the relation between the corrosion-resisting natures and the behaviors of Cr, Ni and Mo contained in these alloys. The present studies verified experimentally that iron nitrides (mainly Fe3N) and spinel type oxides are formed on the corrosion surfaces of 13-Cr and high Mo steels, and CrN crystals are produced inside these surface layers. It was also clarified by electron diffraction that the corrosion surfaces of 18-8 and 25-Cr steels are covered by protective spinel type oxides, and no nitrides can be observed inside these oxide films. In 18-8 stainless steel, Ni layers (or γ-phase layers containing high % of Ni) were detected inside the spinel type oxides. The compact Ni layers (or γ-phase layers) are considered to retard not only the diffusion of Fe, Cr and Ni from the substrate to the surface, but also the penetration of NH3 gas towards the substrate.View full abstractDownload PDF (629K) -
Hidehiko Yoshida1956 Volume 20 Issue 5 Pages 292-294
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn several titanium alloys the β phase, stable at high temperatures, can be retained on quenching. When re-heated at temperatures below 500°, the alloys become hard and brittle. This has been associated with the precipitation of an intermediate phase ω. To determine the structure of this ω phase, single crystal X-ray examination has been carried out on titanium-6 per cent iron alloy. The results obtained are as follows: (1) The ω structure has a complex body-centred cubic lattice and its lattice parameter is aω=9.76 Å. (2) The space group of ω structure is Im3m. (3) The orientation relationships between β phase and ω phase are (100)β\varparallel(100)ω, [010]β\varparallel[010]ω. (4) It is supposed that the ω phase may be an intermetallic compound but its situation on the equilibrium diagram is not clear.View full abstractDownload PDF (578K) -
Isamu Igarashi, Tamotsu Igarashi, Akio Kinukawa1956 Volume 20 Issue 5 Pages 294-295
Published: 1956
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAmmonia stress-cracking tests upon slowly solidified coarse-grained 70 Cu-Zn brass were carried out. At first, fine parallel cracks {111} or {110} appear, next, the cracking direction is changed transverse to the stress direction, finally, fine parallels connecting together as if they were single cracks appear transverse to the stress direction.View full abstractDownload PDF (358K)
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