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Volume 36, Issue 5
Displaying 1-20 of 20 articles from this issue
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Shushi Kinoshita, Takeshi Ueda, Akira Suzuki1972 Volume 36 Issue 5 Pages 403-409
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA low carbon chromium molybdenum steel has been used for a study of the austenitic grain coarsening temperature influenced by hot rolling.
Hot rolling causes the austenitic grain coarsening temperature to lower in proportion to reduction in hot roll. The lower the hot rolling temperature the lower becomes the austenitic grain coarsening temperature.
There are found many needle-like particles of aluminum nitride in the austenite subjected to austenitizing, followed by hot rolling at 1000°C after solution treatment and quenching. On the other hand, polygonals are observed in the austenite subjected to austenitizing after solution treatment and subsequently to hot rolling at 1000°C and quenching.
Particle size measurement of aluminum nitride has shown that the average particle size after the former treatment is smaller than that after the latter.
Since there is no remarkable difference in AlN particle size with and without hot rolling, it is considered that a finer initial austenitic grain size produced by hot rolling is the cause for the reduction of the austenitic grain coarsening temperature.View full abstractDownload PDF (2706K) -
Mitsunori Sato, Masayuki Hijikata, Ichiro Morimoto1972 Volume 36 Issue 5 Pages 410-418
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe silver base contacts containing magnesium, aluminium, manganese, zirconium and cadmium oxides were prepared by internal oxidation. The material transfer and the erosion characteristics of these contacts have been measured in a range of applied voltages from 40 to 212 volts and short circuit currents from 6.4 to 80.1 amperes in direct current, alternating current and full wave rectification circuits.
The characteristics of material transfer and erosion for switching contacts in the direct current and the alternating current circuits can be clarified mostly by a switching test of the full wave rectification circuits. In the switching of the full wave rectification circuit, the direction of material transfer depends on the circuit current. In the region of lower circuit currents than the critical current materials transfer from cathode to anode, and in the higher circuit current region materials moves from anode to cathode. The direction of material transfer and the amount of erosion are affected remarkably by the oxides contained, and depend on the materials of electrodes on the erosion side. In the region where materials transfer from cathode to anode in the direct current and the full wave rectification circuit, the amount of cathode loss is approximately proportional to the arc energy in contact breaking at constant voltage. On the other hand, the ratio of the amount of material transfer or erosion to the arc energy in contact breaking vary with oxides contained.View full abstractDownload PDF (2401K) -
Kazuo Hosokawa, Hiroaki Nishimura, Masuzo Ueda, Fumio Seki1972 Volume 36 Issue 5 Pages 418-424
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA boro-carburizing method impregnating iron with boron and carbon simultaneously by dipping into a hot bath containing ferroboron and Na2CO3 was studied in order to modify the usual boronization of iron.
The results obtained are summarized as follows:
(1) When iron was dipped into a Na2CO3 bath at a temperature of 1000°C, the FeO film alone was formed on the surface and no carburized layer was observed. In a hot bath containing ferroboron and Na2CO3, iron was impregnated simultaneously with boron and carbon which would be produced by the reduction of CO2 with aluminum contained as an impurity in ferroboron.
(2) When iron was dipped into a hot bath consisting of 50% ferroborn and 50%Na2CO3, the Fe2B layer was formed on the surface and below it, a boro-carburized layer showing martensitic structure similar to that of a low carbon steel was observed. In these layers, no pores were found and the hardness of the boro-carburized layer decreased gradually with increasing distance from the surface.
(3) In a hot bath consisting of 40% ferroboron and 60%Na2CO3, the boro-carburized layer alone was formed and its hardness decreased gradually from Hv 1200∼1400 at the surface to Hv 150 at the matrix. The thickness of the layer was 0.7∼1.7 mm for 1∼5 hr at a temperature of 1000°C.View full abstractDownload PDF (2468K) -
Kenzi Mihara, Yasuzi Kataura, Tohei Ototani1972 Volume 36 Issue 5 Pages 424-430
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe graphitizing reaction has been studied by means of a dilatometric method using a number of hyper-eutectoid steels treated with calcium or barium in the temperature range 550° to 700°C. The results obtained were summarized as follows:
(1) The cementite-graphite inversion at 650° to 700°C in the steels treated with calcium or barium was sufficiently rapid and exhibited “C” curve behavior in the T.T.T. relationships except where graphite itself was present before the start of the reaction.
(2) Graphitization occurred at a maximum rate at an additional amount of 1.0% calcium for the steels of 1.3 and 1.5% carbon and was promoted markedly by the prior heat treatment at 400°C.
(3) It was considered that the reaction exponent n (2.5 to 4.0) and the overall activation energies (19 to 34 kcal/mol) for reaction derived from the present work seem to be combined with the diffusion of carbon through ferrite and solution of cementite being the rate-controlling process during subcritical graphitization.View full abstractDownload PDF (1322K) -
Shigeo Zaima, Yasuo Suzuki, Takashi Kamo1972 Volume 36 Issue 5 Pages 430-434
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSLow orthogonal dry cutting tests were performed on commercial pure aluminium (1100) plate to investigate the influence of the cutting conditions on the characteristics of the machined surface in regard to the depth of cut, cutting speed and tool nose radius. The results obtained are summarized as follows:
The deformed layer increases its hardness and thickness with increase in the depth of cut. The roughness of the machined surface increases with increase in the depth of cut if the tool nose is round, but if the tool nose is not round, there is no difference in the surface roughness regardless of the depth of cut when the depth of cut is small and the surface roughness is suddenly deteriorated beyond a certain degree of the depth of cut. As long as the tool nose radius is small, the cutting resistance and the surface roughness increase, but when the tool nose is over a certain radius, the cutting resistance and the surface roughness remain almost constant. The main cause is considered as follows. The contour radius of the built-up edge, which grows and adheres on the negative rake side of the tool nose and participates in cutting, is nearly equal regardless of the nose radius if the tool nose is over a certain radius. In the experimental cutting speed range, the surface roughness is not so affected by cutting speed.View full abstractDownload PDF (1268K) -
Kazuyoshi Sekine1972 Volume 36 Issue 5 Pages 435-440
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to examine the mechanisms of the texture transition in fcc metals, copper single crystals having a near (133)[\bar1\bar44] orientation were rolled up to 97 pct at room and liquid-nitrogen temperatures, and the orientation changes occurring during rolling were followed by determination of X-ray pole figures for various degrees of reduction in thickness.
When rolled at room temperature, the crystal initially rotated toward (011)[\bar1\bar11] orientation by the operation of normal slip systems with the highest resolved shear stress. After the rolling plane normal had arrived at the vicinity of (011), it displaced toward (\bar121) with increasing rolling reduction. Eventually the (1\bar32)[\bar1\bar11] texture was developed by 97 pct rolling. When rolled at the liquid-nitrogen temperature, the main component crystal decreased mainly by mechanical twinning on the way of slip rotation toward (\bar121)[\bar1\bar11], and the near alloy type rolling texture was developed at a high rolling reduction. The results obtained in the present investigation indicate that the mechanical twinning is the major mechanism responsible for the texture transition of fcc metals.View full abstractDownload PDF (1992K) -
Satoru Asawa, Shiro Haruyama, Kyuya Nagasaki1972 Volume 36 Issue 5 Pages 440-444
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of plastic deformation on the electrochemical behavior of copper was investigated in copper sulfate solution and in sulfuric acid solution.
The electrode potential was restrained to either the reversible potential or the corrosion potential by an electronic potentiostat. The electrode was elongated at a constant strain rate with an Instron type testing machine.
It was found that the electrode yielded anodic current during the plastic deformation. There was no appreciable slip lines after the deformation of specimen in solution, whereas the distinct slip lines were visible after the deformation in air.
The behaviors were explained in terms of the anodic dissolution of an active slip zone formed by plastic deformation.View full abstractDownload PDF (1178K) -
Tatsuhiko Shigematsu, Sanji Nishimura, Teruo Tanabe, Yoshio Kondo1972 Volume 36 Issue 5 Pages 445-450
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe equilibrium in the solvent extraction of europium by Versatic Acid 911 was studied. The organic phase was composed of Versatic Acid and benzene, and the aqueous solution of Eu(NO3)3 and HNO3 was used. The ionic strength of the latter solution was maintained at a unity by adding NaNO3. Radioactive Eu152 was used as a tracer. From the measurements carried out at 25°C, the equation of extraction and the apparent equilibrium constant was determined as follows:
(This article is not displayable. Please see full text pdf.)
where R2H2 refers the dimeric form of Versatic Acid in benzene solution.View full abstractDownload PDF (1223K) -
Yoshiichi Sakamoto1972 Volume 36 Issue 5 Pages 450-457
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe electrodeposition from chromic acid solutions has been investigated under various conditions. The results obtained are as follows:
(1) The depositions with hcp and fcc types tend to deposit under the following conditions; (i) high concentration of chromic acid in the bath, (ii) low temperature of the bath, (iii) high current density and (iv) the use of pulsating direct current. The effects of addition agents which may reduce the trivalent chromium are not essential to form these deposits.
(2) Both the hcp and fcc type deposits are chromium hydride CrHx(x\simeq1) but not CrH2 which was reported by Snavely for the fcc type deposits.
(3) The current efficiency for the hcp type deposits is 27∼37% and that for the fcc type deposits is 7∼13%.
(4) The lattice constant of the hcp type deposits is a=2.722±0.003 Å, c⁄a=1.629±0.01 and that of the fcc type is a=3.8585±0.0003 Å. However, the lattice constant of bcc chromium deposited from a standard chromic acid bath increases from about 2.8809 to 2.8880 Å with increasing bath temperature from 40° to 75°C.View full abstractDownload PDF (2335K) -
Yoshiichi Sakamoto1972 Volume 36 Issue 5 Pages 458-463
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of heating time and temperature on the transition of electrodeposited chromium hydrides with the structures of hcp and fcc types to bcc chromium and the changes in micro-strain and domain size in deposits were investigated by X-ray diffraction before and after the transition. With increasing temperature, both the hcp and fcc type deposits are rapidly transformed into bcc chromium by thermal decomposition. The fcc type deposit transforms into bcc chromium indirectly after forming hcp structure intermediately. The transition is accompanied with the increase of micro-strain and the decrease of domain size. These phenomena are related to the formation of cracks due to the reduction of volume.View full abstractDownload PDF (1603K) -
Hideya Okada, Yuzo Hosoi, Seizaburo Abe1972 Volume 36 Issue 5 Pages 464-470
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe metal dissolution and the change in couple current (flowing between non-stressed and stressed specimens) have been measured in the process of stress corrosion cracking of austenitic stainless steels in MgCl2 solution boiling at 143°C.
\ oindentThe results obtained are as follows:
(1) The metal dissolution occurs when the material is stressed beyond yield stress, (2) the metals dissolved during stress corrosion cracking are Fe and Ni, whereas the dissolution of Cr is not detected, (3) it is found that the increases in the metal dissolution and the couple current are closely related to the propagation of cracks, (4) non-sensitive material to stress corrosion cracking does not show any metal dissolution and flowing of the couple current, (5) the cracks initiate at the slip steps where fresh surfaces are exposed by plastic deformation, and (6) the propagation of cracks is stopped by the addition of a small amount of NaNO3 in the test solution and by the cathodic polarization.
From these experimental facts, the process of stress corrosion cracking of austenitics stainless steel in MgCl2 solution can be considered as follows: At the beginning, the fresh surface exposed by slip is preferentially attacked by a corrosive environment and a groove is formed by the metal dissolution at this area, resulting in the crack initiation. At the crack tip, slip accompanied by the metal dissolution occurs again; thus the crack propagates by a cooperative action of the slip and the metal dissolution and finally the material is fractured.View full abstractDownload PDF (2460K) -
Kunio Shiobara, Susumu Morioka1972 Volume 36 Issue 5 Pages 471-476
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this paper, the effects of halogen ions and temperature were investigated on the pitting and crevice corrosion of 18Cr-8Ni stainless steel. The results obtained were summarized as follows. (1) In the anodic polarization curves of 18Cr-8Ni stainless steels in 0.1 M NaCl solution below 10°C, stable repassivation was observed at the potentials above 1.1 V (Eh), whereas in those of specimens in the crevice, no similar phenomenon was observed. (2) Apparent activation energies obtained for the onset of pitting and crevice corrosion were about 98.6 and 86.4 kcal/mol, respectively, and those for stationary state were about 4 kcal/mol for both. (3) The critical pitting potentials of 18Cr-8Ni stainless steel in the halide solutions were in the following order: Cl−≥Br−>I−, and the crevice corrosion potentials were, on the contrary, in the order: Cl−<Br−<I−. (4) From the results mentioned above, it is considered that the major cause for the crevice corrosion is the restricted supply of H2O and OH− ions in the narrow crevice, and that the higher EX0 of the hologen ions in the solution, the higher becomes the critical pitting potential because of the easy supply of H2O and OH− ions on the open surface which contributes to the repair of the surface film.View full abstractDownload PDF (1820K) -
Hideo Abe, Kineo Takagi, Katsuhiro Itayama1972 Volume 36 Issue 5 Pages 476-481
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSChanges in (222), (112), (200) and (110) pole intensities and average intercept length \barD of recrystallized grains during isothermal annealing at 750°, 800° and 850°C have been observed in low carbon rimming steel sheets cold rolled by 60, 70 and 80% reductions in thickness. Linear relations exist between \barD and (222) pole intensity. The values of exponent n in an empirical equation \barD=ktn, where k is a parameter and t is the annealing time, for the isothermal annealing are 0.25∼0.27, which are in good agreement with the values obtained by Wiener in high purity iron. The average intercept length \barD111 of the recrystallized grains with {111} orientation is always larger than \barD, whereas the values of exponent n obtained from both measurements are nearly the same (n=0.25). The amount of the {111} component after the primary recrystallization is increased by processing from the hot strip with a structure of finely dispersed cementite particles, and the increase of the {111} component is maintained during the subsequent grain growth process.View full abstractDownload PDF (1599K) -
Toshio Oishi, Takashi Hiruma, Joichiro Moriyama1972 Volume 36 Issue 5 Pages 481-485
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSElectromotive force measurement of galvanic cells involving oxide electrolytes have been made in order to obtain the standard free energy of formation of SnO2 in the temperature range 900°∼1100°C and the thermodynamic properties of copper and tin in liquid Cu-Sn alloys at 1100°C.
The standard free energy of formation of SnO2 was determined: ΔF(SnO2)°=−134.7+46.9×10−3T (kcal/mol) between 900° and 1100°C. The activity of tin in liquid Cu-Sn alloys showed a negative deviation from Raoult’s law at copper rich alloys and a slight positive deviation in the tin-rich alloys, and that of copper showed a negative deviation in the whole concentration range. Furthermore, other thermodynamic properties were also calculated.View full abstractDownload PDF (1206K) -
Masamichi Kowaka, Sabro Nagata1972 Volume 36 Issue 5 Pages 486-492
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe oxidation of commercial austenitic stainless steels for boiler superheater tubes has been investigated in steam at a temperature range of 600°∼650°C. The results obtained are as follows:
(1) The oxidation rate of austenitic stainless steels decreased with time and increased with temperature.
(2) The oxidation rate of austenitic stainless steels in steam, was greatly affected by the grain size of the steels. The grain size of the steels was inversely related to the oxidation in steam, and it was explained by the formation of a protective Cr2O3 film due to the accelerated diffusion of chromium in the grain boundaries.
(3) The thickness of scale on the surface was proportional to the amount of oxidation in steam, and the outer scale was spalled off after growing to a definite thickness.
(4) The grinding of the metal surface reduced considerably the oxidation rate in steam.
(5) The rate of oxidation in steam was markedly greater than that in air.
(6) Electron microprobe analysis of the austenitic stainless steels oxidized in steam showed the distribution of Fe, Ni, Cr and O2 in the scale. The outer layer was composed of both α-Fe2O3 and Fe3O4, the inner layer being of the spinel type containing (Fe, Ni, Cr) oxides.View full abstractDownload PDF (2526K) -
Hakaru Masumoto, Shôhachi Sawaya, Michio Kikuchi1972 Volume 36 Issue 5 Pages 492-497
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMeasurements of Young’s modulus at −150°∼400°C and of rigidity modulus, thermal expansion and hardness at room temperature have been carried out with Mn-Cu-Mo alloys subjected to cold working and a variety of heat treatment. In the Young’s modulus vs temperature curves, Mn-Cu-Mo alloys of about 30.10∼60.22%Cu and 3.10∼20.35%Mo slow cooled after heating for 1 hr at 900°C showed distinct anomalous changes which seem to be related to the antiferromagnetic\ ightleftarrowsparamagnetic transformation. Young’s medulus at room temperature is generally higher in the annealed state than those in the cold worked or water quenched state and tends to increace with rise of reheating temperature after cold working or water quenching. The temperature coefficient of Young’s modulus shows a wide variation with the operations of annealing, water quenching, cold working, and reheating after water quenching or cold working, and also with alloy composition. It is to be noted that the temperature coefficient of Young’s modulus as a function of composition exhibits a large positive maximum, thus showing the Elinvar property. The variation in rigidity modulus and its temperature coefficient with heat treatment, cold working and composition shows a close similarity to that in Young’s modulus and its temperature coefficient. The hardness shows a very complicated change with composition, heat treatment and cold working of the alloys, showing Vickers hardness of about 130 to 700. The oxidation and corrosion resistances of Mn-Cu-Mo alloys are fairly good.View full abstractDownload PDF (1413K) -
Hakaru Masumoto, Shôhachi Sawaya, Michio Kikuchi1972 Volume 36 Issue 5 Pages 498-503
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMeasurements of Young’s modulus at −150°∼400°C and of rigidity modulus, thermal expansion and hardness at room temperature have been carried out with Mn-Cu-W alloys subjected to cold working and a variety of heat treatment. In the Young’s modulus vs temperature curves, the ternary alloys slow cooled after heating for 1 hr at 900°C showed distinct anomalous changes which seem to be related to the antiferromagnetic\ ightleftarrowsparamagnetic transformation. Young’s modulus at room temperature did not show a large difference among the annealed, cold worked or water quenched states, but this value tend to increace with increasing manganese or tungsten contents. The temperature coefficient of Young’s modulus shows a wide variation with the operation of annealing, water quenching, cold working or reheating after water quenching or cold working, and also with alloy composition. It is to be noted that the temperature coefficient of Young’s modulus as a function of composition exhibits large positive maximum, thus showing the existence of the Elinvar property. The variation in rigidity modulus and its temperature coefficient with the heat treatment, cold reduction rate and composition shows a close similarity to that in Young’s modulus and its temperature coefficient. The hardness shows a very complicated change with the heat treatment, cold reduction rate and composition of the alloys, showing Vickers hardness of about 100 to 660. The corrosion resistance of Mn-Cu-W alloys is fairly good.View full abstractDownload PDF (1862K) -
Masahisa Otsuka, Ryo Horiuchi1972 Volume 36 Issue 5 Pages 504-508
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA remarkable solution softening phenomenon was found in the tensile test of Al-Mg-Zn alloys at high temperatures. The effect of zinc addition was studied and the softening mechanism is discussed.
\ oindentThe results are summarized as follows:
(1) The flow stress level decreased linearly with increase in the concentration of zinc. The decreasing rate was about 4% per 1 at% of zinc.
(2) The high temperature deformation behavior of Al-Mg alloy was not changed essentially by the addition of zinc. For both binary and ternary alloys, the mechanical equation of state is given as
(This article is not displayable. Please see full text pdf.)
where A is a constant depending on the concentration of zinc, n=3.3 and Q=36∼37 kcal/mol.
(3) The high temperature deformation of Al-Mg-Zn alloys as well as that of Al-Mg alloys depends on the viscous motion of dislocations which drag magnesium atmospheres formed around them. The solution softening observed can be attributed to the enhanced diffusivity of magnesium which is caused by the addition of zinc.View full abstractDownload PDF (876K) -
Hideo Suzuki, Yusaku Masuda, Keizo Nishida1972 Volume 36 Issue 5 Pages 509-513
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAn iron test piece was diffusion annealed in an evacuated two-stage capsule with pure Zn metal as a vapor source at 700°∼980°C and each diffusion-penetration curve with the ordinate of a volume fraction unit was analyzed by means of Balluffi’s method to determine the dependence of interdiffusion coefficients (\ ildeD) on the concentration of Zn. The \ ildeD value at each temperature increased greatly with Zn concentration in the range of α-solid solution. The dependence of \ ildeD on temperature in the Arrhenius plot showed a good linearity, from which the activation energy for interdiffusion (\ ildeQ) was calculated. The energy varied from 58 kcal/mol for 3 at%Zn to 46 kcal/mol for 18 at%Zn and was evaluated to be about 62.5 kcal/mol for the impurity diffusion of Zn in iron. Fine alumina markers placed initially on the test piece were found always on its surface after annealing, so that it is suggested that Zn atoms diffuse in predominantly in the α-range of an Fe-Zn system. The variation of frequency factor (\ ildeD0) with the activation energy for interdiffusion (\ ildeQ) showed also a good linear relation, where the following equation would be held:
(This article is not displayable. Please see full text pdf.)View full abstractDownload PDF (1421K) -
Hisashi Suzuki, Kozi Hayashi, Osamu Terada1972 Volume 36 Issue 5 Pages 514-518
Published: 1972
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe transverse-rupture strength and the hardness of TiC-(10∼30)%Mo2C-(10∼20)%Ni alloys were investigated in relation to the mean free path or the mean grain size of the carbide and the mean grain size of titanium carbide (occluded in the carbide). Various specimens with various microstructures were prepared by ball-milling and sintering at 1300∼1450°C for 1∼8 hr.
The results obtained were as follows: (1) Transverse-rupture strength vs. mean free path curves showed a maximum in the same way as WC-Co alloy, when the mean grain size of titanium carbide was always kept constant. (2) Hardness decreased lineally with increasing logarithm of mean free path, and it decreased also slightly with increasing amount of Mo2C. (3) The mean grain size of carbide in sintered alloys seemed to be controlled, under a definite sintering condition, by the ratios of Mo2C/Ni and TiC/Mo2C.View full abstractDownload PDF (1453K)
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