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Volume 26, Issue 7
Displaying 1-15 of 15 articles from this issue
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Hifumi Hotta, Yoshiroh Iwama1962 Volume 26 Issue 7 Pages 407-412
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe variation with temperature of the internal friction of aluminum alloys was studied by torsion pendulum method. In temperature ranges, 40°C to 150°C and 200°C to 280°C, the decrement of solution treated alloys exhibited a first peak and a second peak. The height of the two peaks varied with aging conditions, components of the alloying element and grain sizes of the specimen. An explanation of such a behavior on age-hardening processes was developed. In the first peak, the initial increase of the decrement with temperature was attributed to the thermally activated motion of dislocation lines, and the subsequent decrease to the supression of the dislocation motion by a formation of Guinier-Preston zone. The second peak was attributed to variation of the grain-boundary relaxation due to a precipitation of θ′ (or S′) compound at the boundaries.View full abstractDownload PDF (824K) -
Kazuaki Iijima1962 Volume 26 Issue 7 Pages 412-416
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of austenitizing conditions, such as austenitizing temperature, austenitizing time and the austenitizing temperature in previous heat treatment, on the hardenability and the mechanical properties of hardened eutectoid carbon steel were determined, and the relations between those properties and the austenitic grain size were ascertained, with the following results: (i) The higher the austenitizing temperature, the lower the toughness of hardened steel, the greater its hardenability, and the coarser its austenitic grain size; (ii) a longer austenitizing time gives the same effect as higher austenitizing temperature on those properties, but in some cases, an abrupt change in toughness and hardenability unrelated with austenitic grain size was observed; (iii) even if the austenitizing temperature in final hardening was maintained constant (800°C), the toughness and the hardenability were remarkably affected by the austenitizing temperature in previous heat treatment, such as annealing, hardening and annealing after hardening, where the higher was the austenitizing temperature, the toughness fell the lower and the hardenability rose the higher. But, in all cases, the austenitic grain size was scarcely affected by previous heat treatment; (iv) the above results suggest that decrease in toughness and increase in hardenability due to overheating would be attributed to some change in austenite produced by the overheating process itself, in addition to austenitic grain coarsening.View full abstractDownload PDF (575K) -
Kazuyoshi Nishino1962 Volume 26 Issue 7 Pages 416-420
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe strain age hardening of austenitic Ni-Cr steels was studied chiefly by the comparison between the one-phase alloy and two-phase alloys containing martensite. The results obtained were as follows. (1) The strain age hardening occurs in two stages on annealing below 475°C after cold work, and there seems to be no difference in the nature of the hardenings between the one-phase and the two-phase alloys. (2) The strain age hardening is as hardly accompanied by a rise of yield point as in the cases of carbon steels and copper alloys, when measured under a stress of the same kind and direction as those of prior working, probably indicating that the rise is directional. (3) The degrees of strain age hardening and inelastic effect observed on unloading after extension are approximately proportional to f3⁄2 in the range where the volume fraction of martensite (f) is relatively small, leading to the presumption that the hardening is closely related with the pile-up dislocation and the back stress.View full abstractDownload PDF (620K) -
Kazuyoshi Nishino1962 Volume 26 Issue 7 Pages 420-425
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen a heavily rolled specimen of austenitic Ni-Cr seels is bent, the hardness increases markedly beyond the expected effect of work hardening. This hardening, say, secondary work hardening, is generally obtained by slight application of a secondary working differing in type from the primary, and it is presumed that the strain age hardening and the secondary work hardening are induced by nearly the same cause, irrespective of presence and absence of the second phase, in other words, the hardening does not necessarily need a diffusion of solute atoms. The possible mechanism for the hardening may be as follows. During cold working, a large number of pile-up dislocations are formed around the barriers. After low temperature annealing, the dislocations move back and react with the other groups under the influence of the back stress originated in the pile-ups, so that they become difficult to move. The higher the dislocation density the easier the rearrangement. The martensite phase is a strong barrier, and its presence brings about a marked strain age hardening.View full abstractDownload PDF (853K) -
Kinji Yokoyama, Tomoo Suzuki1962 Volume 26 Issue 7 Pages 426-429
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate into the fact that, with various tool steels, the quenching-deformation is anisotropic against the rolling direction, some specimens were cut out from seven species of tool steel bars A (JIS SKD 1), B (SKD 2), C (SKD 12), D and E (SKS3), F (SKS 2) and G (SUJ 2) either in the longitudinal or in the transversal direction and subjected to quenching under various conditions. The change of length of the specimens then was measured with a Carl Zeiss U.M.M. and a Leitz dilatometer as well as the hardness and the structure were observed. The results obtained were as follows: (1) In the case of quenching specimens of the first group (steel A & B), the linear expansion of the longitudinal specimens was larger than that of the transversal specimens, while if a contraction occurred owing to quenching, the linear contraction of the longitudinal specimens was less than that of the transversal ones. On the contrary, in the case of quenching specimens of the second group (steel C, D, E, F & G), linear expansion of the longitudinal specimens was less than that of the transverse specimens, while if a contraction occurred also due to quenching, the linear contraction of the longitudinal specimens was larger than that of the transversal ones. Namely, the behavior of deformation was found to be opposite in the two groups. (2) After investigation into the experimental results of dilatometric and structural observations with steels A & D, the cause of deformations described above was made clear.View full abstractDownload PDF (581K) -
Tomoo Suzuki1962 Volume 26 Issue 7 Pages 429-433
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy using specimens of 8 kinds of melted high Cr-steels containing a structure within α+η carbide and specimens of commercial JIS SKD 1 and SKD 12 steels, some investigation was carried out by measurements of the length-change with a Zeiss U.M.M. and a thermal dilatometer, hardness as well as by microscopic observation. The experimental results obtained were as follows: (1) With specimens containing the less C, the less Cr and the less carbide, the expansion due to quenching was the more marked in the transversal specimens than in the longitudinal specimens. On the contrary, with steel specimens containing more C and more Cr, the expansion behavior was reversed. And e.g. with steel specimens containing about 1%C and 7%Cr in the case of oil-quenching from 950°C, the quenching-deformation of longitudinal and transversal specimens becomes equal. (2) From the result of dilatometric method, in existence of various phenomena that were presumed to be caused by carbide particles present in the structure and arranged in the rolling direction was clearly shown.View full abstractDownload PDF (761K) -
Gunji Shinoda, Yoshitsugu Amano1962 Volume 26 Issue 7 Pages 433-437
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCorrosion in a condenser tube sheet made of Cu-Al-Fe-Ni alloy was investigated. The fillings between α phase were preferentially corroded and became red. This red part was confirmed by X-ray diffractmeter as pure copper. By X-ray transmission photographs it was determined that the direction of its growth is ⟨001⟩ and coincides with the fibre axis of electroplated copper. Therefore, copper preferentially deposited from the solution containing Cu, Al, Ni, etc. From the differences of lattice constants of α phase of original material and that of corroded part, it was concluded that the compositions of the α phase has a certain range and the concentration of Al is lowest in the centre of grain.View full abstractDownload PDF (1130K) -
Kôichi Aoki, Shôzô Sekino, Toshiyuki Fujishima1962 Volume 26 Issue 7 Pages 437-442
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThree Al-killed deep drawing steel sheets (sol. Al: 0.04, 0.02, 0.003∼6%) were solution-treated (1250°C×1.5′) and kept isothermally between 200°∼900°C. Precipitation of C and N in the specimens were investigated by chemical analysis, and internal friction. It was found that the rate of N precipitation is the fastest at about 770°C, and there is no simple relation between NIF (interstitially solved N determined by internal friction) and N as AlN, and with increasing sol. Al, CIF at equilibrium decreases over 300°C, and NIF decreases especially between 600°∼700°C,View full abstractDownload PDF (1070K) -
Takashi Shimanuki, Kichinosuke Hirokawa, Hidehiro Gotô1962 Volume 26 Issue 7 Pages 443-446
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSApplications of calibration curve method and and calculation method by Hirokawa’s equation were tried for the determination of alloying elements in ferromanganese or ferrochromium. Non-destructive method in routine analysis was unsuccessful owing to the segregation and porosity generally existing in ferromanganese and ferrochromium. Moreover, they are poor in machinability. Therefore the authers examined the homogeneous samples by the following methods: (1) Powder; graphite powder ten times of the sample (Wg⁄Ws) was added to the nitric acid solution of ferromanganese and hydrochloric acid solution of ferrochromium, and then the mixture was evaporated and dried. (2) Solution; ferromanganese was dissolved in nitric acid, and ferrochromium was fused with sodium peroxide. By the powder method (1), the linear calibraton curves for ferromanganese and for ferrochromium up to about 50 per cent were obtained. By the solution method (2), the linear calibration curves for manganese from 60 to 90 per cent and for chromium from 50 to 70 per cent were obtained. The standard deviation for ferromanganese and ferrochromium were 3.45 and 2.67 by the method (1), and 1.16 and 0.93 by the method (2).View full abstractDownload PDF (477K) -
Sakae Takeuchi, Kenji Suzuki1962 Volume 26 Issue 7 Pages 447-452
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe hydrogen pressure-composition isotherms for plutonium-hydrogen system have been studied experimentally by Mulford and Sturdy. It has been considered that the stoichiometric plutonium dihydride phase has the fluorite structure, in which plutonium atoms occupy the face centred cubic lattice sites and hydrogen atoms are located in the tetrahedral sites of plutonium lattice, and the plutonium dihydride phase is a non-stoichiometric berthollide compound which can exist in the erange of composition from 1.8 to 2.75 hydrogen atoms per plutonium atom. But, it is expected that hydrogen atoms can occupy the tetrahedral and octahedral sites in the face centred cubic lattice of plutonium atoms. Based on the assumption described above, the equilibrium between the nonstoichiometric plutonium dihydride phase and hydrogen gas was investigated statistico-thermodynamically. The energies of the mutual interaction between hydrogen atoms in tetrahedral or octahedral sites and plutonium atoms surrounding them and the potential energies of pairs of hydrogen atoms were calculated, respectively. The ratio of hydrogen atoms in tetrahedral and octahedral sites was estimated as the function of temperature, hydrogen concentration and the difference between the energies of hydrogen atoms in both sites. From the results of the theoretical study, it was concluded that hydrogen atoms were located preferentially in tetrahedral sites and the number of hydrogen atoms in octahedral sites increased with increasing temperature and hydrogen concentration. It was found that the calculated hydrogen equilibrium pressure for the nonstoichiometric plutonium dihydride phase agreed well with the experimental results by Mulford and Sturdy.View full abstractDownload PDF (690K) -
Saburo Ishikawa, Teiji Mikami, Kazuo Nakazawa1962 Volume 26 Issue 7 Pages 452-456
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been found that Se whiskers grow on Mg and its alloys with Al and Zn immersed in an aqueous solution of selenious acid (H2SeO3), and the effects of the concentration of the solution and of the alloying elements on the whisker growth were studied under a metallurgical microscope and by X-ray analysis. Some whiskers appeared first on Mg or its alloys immersed in the solution for 20∼30 minutes, and after 1∼5 hours the number of the whiskers increased remarkably. Then, the whisker growth retarded and stopped after 24 hours. The time required for the growth of each whisker was 30∼120 seconds. In 2% solution whiskers hardly grew, and in 4% solution the number of the whiskers increased remarkably, but in more concentrated solutions the number of the whiskers remained almost the same. With increasing content of Zn and Al up to 8%, the number of the whiskers and their sizes became larger, while the whiskers hardly grew on Mg-40%Al alloy. The maximum length of the whiskers was 2 cm. The whiskers had round pipe-like section and their diameter was 0.1∼0.01 mm. The crystal structure of the whiskers is hexagonal and each whisker is not a single crystal but a polycrystal.View full abstractDownload PDF (760K) -
Tohei Ototani, Yasuhiro Morooka, Yasuzi Kataura1962 Volume 26 Issue 7 Pages 456-461
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt has been found that nodular graphite steel may be more readily obtained in the as-cast condition by addition of a suitable iron-calcium base alloy to molten steel of hypereutectoid composition and of lower silicon content. Steel samples containing 1.1∼1.5%C were melted in a magnesia-lined high-frequency induction furnace. The melt was divided into two or three parts, each part being treated with 0.8 or 2.0% of the iron-calcium base alloy and cast into a CO2 sand mould or a dry sand mould of keel block type. After various heat treatments, test pieces were machined from these steel castings. The result of this experiment may be summarized as follows: (1) The mechanical properties of nodular graphite steel castings in the heat-treated condition were better than those of the as-cast condition. The specimens with spheroidized pearlite structure showed high tensile strength and high ductility such as tensile strength of 70∼85 kg/mm2 and elongation or reduction of area of about 10% respectively. (2) With increasing carbon contents, the ratio of graphitization increased and the specimens with ferrite structures showed stronger graphitization than those with any other structures.View full abstractDownload PDF (1157K) -
Kozo Morinaga, Teruo Ikeno, Masakazu Sugimori, Bunji Eto, Hideaki Soma1962 Volume 26 Issue 7 Pages 461-466
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPreviously the authors have reported on the configuration of Ti compounds in pig iron. This investigation was undertaken to study the mechanism of occurence of casting defects, such as to pin holes, in casting goods containing Ti. The results obtained were as follows: (1) The castings having 0.055∼0.13%Ti were apt to have casting defects like pin holes. This tendency was promoted by higher casting temperature and slower cooling velocity during solidification. (2) When a sample having casting defects like pin holes was divided into several parts, TiC(N) was rich in parts having much defects and TiN(C) rich in parts having little or no defects. (3) It is considered that defects like pin holes in castings containing Ti are due to N2, which is formed reaction TiN+C→TiC+1/2 N2.View full abstractDownload PDF (917K) -
Zen-ichi Tanabe1962 Volume 26 Issue 7 Pages 467-471
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe recent widespread use of aluminium bronze in industry may be attributed to its high mechanical properties and resistance to corrosion. In certain corrosive environments, however, aluminium bronze can suffer a selective corrosion known as dealuminization. This selective corrosion phenomenon results in a loss of aluminium from the alloy. Dealuminization in aluminium bronze is similar in mechanism to the dezincification that occurs in brass. Dealuminization was studied by means of rapid dipping tests and anodic polarization measurements on various Al-Cu alloys, in which the content of Al was not larger than 12%, in solutions of CuSO4(1/2 mol), CH3COONa(1/3 mol), KCl(1/3 mol) and CH3COOH(2/3 mol). The pH value of the above mentioned solution was 3.3. The results obtained were as follows: (1) The anodic current density at −0.05 V(vs. S.C.E.) corresponds to the dealuminization degree of each alloy. (2) Only alpha Al-Cu alloys have high resistivity to the dealuminization in aluminium bronze. (3) The other phases of Al-Cu alloys are more easily dealuminized than the alpha phase. (4) The dealuminization degree of 12%Al-Cu alloys is remarkably influenced by heat treatment.View full abstractDownload PDF (1165K) -
Yataro Saito1962 Volume 26 Issue 7 Pages 472-478
Published: 1962
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe redox potential of some etching reagents and the corrosion potential of various stainless steels and alloys were measured and the etching behavior of γ, α and σ phase in stainless steel were explained electrochemically. The results obtained were as follows: (a) In acid reagents, low-chromium ferritic and austenitic stainless steels are corroded but high chromium alloys fell into the passive state. For this reason when stainless steel containing σ phase is etched in acid reagents, γ or α phase are corroded and σ phase, higher in chromium than α or γ phase, is not corroded. (b) On the other hand, in alkaline reagents, low-chromium austenitic stainless steels are not corroded but high-chromium stainless steels and alloys are corroded and stained. For this reason, when stainless steel containing σ phase is etched in the alkaline reagents, γ phase is not corroded and α or σ phase are corroded and stained.View full abstractDownload PDF (1227K)
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