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Volume 30, Issue 5
Displaying 1-19 of 19 articles from this issue
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Taichi Kamijo1966 Volume 30 Issue 5 Pages 415-421
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA (001)[110] orientation rotates about the transverse direction towards a {112}⟨111⟩ orientation during rolling up to 75 pct. This displacement takes place under the operation of two slip systems which hold the slip plane in common. Increasing a rolling reduction, the {112}⟨111⟩ orientation tends to rotate towards a {011}⟨211⟩ orientation. A (122)[\bar411] orientation which is a twin component of a cube texture moves primarily to a (011)[\bar100] orientation. The (011)[\bar100] orientation reaches a {011}⟨211⟩ orientation by a rotation around the rolling plane normal. After rolling of 96.7 pct., the main component of the rolling texture is composed of the {112}⟨111⟩ orientation. The stabilization of the {112}⟨111⟩ orientation can be considered to take place owing to the retardation of the rotation to the {011}⟨211⟩ orientation, in case extensive cross slip occurs.View full abstractDownload PDF (1799K) -
Taichi Kamijo1966 Volume 30 Issue 5 Pages 421-428
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSlip rotations towards stable end orientations are studied on a standard stereographic projection, assuming that slip systems of the type {011}⟨111⟩, {112}⟨111⟩ and {123}⟨111⟩ must operate together. Material initially oriented in a way that a direction ⟨112⟩ lies between the rolling direction and the operative slip direction, will take up primarily an orientation {111}⟨112⟩ or {554}⟨225⟩. Since the {111}⟨112⟩ orientation is considered as meta-stable, the rolling plane normal and the rolling direction have to displace along great circles so as to reach a {112}⟨110⟩ orientation, under the operation of conjugate slip on systems {011}⟨111⟩ bearing a maximum resolved shear stress. As the second displacement can be explained by the rotation about the ⟨110⟩ axis lying at 60° from the rolling direction towards the rolling plane normal, a partial fiber texture described as RD-60°\varparallel⟨110⟩ FT will be formed accordingly. In the case when a direction ⟨110⟩ lies between the rolling direction and the operative slip direction, the rolling direction will rotate towards ⟨110⟩ and the rolling plane normal will aproach the great circle ⟨001⟩–⟨112⟩. Since the operation of slip systems {011}⟨111⟩ causes the rolling plane normal to move from ⟨001⟩ to ⟨112⟩ and that of {112}⟨111⟩ gives rise to an inverse displacement, both the rolling plane normal lying between ⟨001⟩–⟨112⟩ and the rolling direction at ⟨110⟩ are considered to be stable. According to this displacement, another partial fiber texture with ⟨110⟩ parallel to the rolling direction can be formed. In consequence, orientation {001}⟨110⟩ and {111}⟨112⟩ are dominant in the rolling textures in α-iron at low reduction. With increasing reduction, the component {111}⟨112⟩ decreases and the material having {112}⟨110⟩ orientation increases.View full abstractDownload PDF (2718K) -
Ken’itiro Suemune, Takayuki Ôoka1966 Volume 30 Issue 5 Pages 428-434
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe three Fe-Mn alloys water-quenched, furnace-cooled from 1100°C or hammered after such treatments were studied by means of transmission electron microscopy, mainly on the structure of ε phase and its formation behavior in relation with the α′ phase.
The results are as follows: In water-quenched 18.3%Mn-alloy, the ε phase is plate-like lying on {111}γ atomic planes. The ε phase generally have stacking faults of high density on (0001) planes all over the grain, as already reported in the literature, but some ε grains do not have such faults but only dislocations. The ε plate and its parent grain are oriented satisfying Syoji-Nishiyama’s orientation relationships. The α′ phase does not exist in this alloy.
In the 18.3%Mn alloy hammered after water-quenched or furnace-cooled, a small amount of the α′ phase is observed.
In water-quenched 13.5%Mn alloy, the ε and α′ phases coexist, their transformation temperatures being very close to each other. An electron microscope structure is obtained in which the formation of the α′ phase seems to have induced that of the ε phase.
9.73%Mn alloy, both in the case of the water-quenched and the furnace-cooled, consists of the α′ phase, while the ε phase is hardly observed.View full abstractDownload PDF (2131K) -
1966 Volume 30 Issue 5 Pages 434
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPlease see pdf. Wrong:D.F.=(μ1−μ2/μ0μ1)log10t2/t1 Right:D.F.=μ1−μ2/μ0μ1·log10t2/t1View full abstractDownload PDF (16K) -
Takayuki Ôoka, Kazuo Sugino1966 Volume 30 Issue 5 Pages 435-441
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe change in microstructure on quenching and tempering, and the precipitation process of austenite in 9% nickel steels with 0.001, 0.01 and 0.1% carbon, which were carefully prepared by vacuum melting, have been investigated by transmission electron microscopy and the X-ray diffraction method and from the transformation characteristics on continuous cooling. The main results are as follows: (1) The typical structure of a 0.1%C 9Ni steel, when cooled at rates above 2.5°C/min, is the mixed structure of martensite and bainite which contain dislocations of high density. The internal twins were also observed in the martensite and the oriented carbide-precipitates in the bainite. In steels with the carbon content less than 0.01%, when quenched from the austenite field, the massive structure with dislocations of comparatively low density was observed. (2) The volume fractions of the austenite retained on cooling or precipitated on tempering were determined by the X-ray method, and it was found that the retained austenite played an important role in the enhancement of the precipitation of austenite particularly in the early stage of tempering. (3) On tempering a 0.1%C 9Ni steel at about 525°C, a considerable amount of austenite is formed at the expense of carbides precipitated there. The austenite thus formed is extremely stable even at −196°C. However, the austenite precipitated on tempering at higher temperatures such as above 600°C becomes less stable, thereby it is transformed into martensite on cooling from the tempering temperature. The stability of the precipitated austenite is also much reduced as the carbon content of specimen is lowered.View full abstractDownload PDF (2276K) -
Takayuki Ôoka, Hiroshi Mimura, Seinosuke Yano, Kazuo Sugino, Tak ...1966 Volume 30 Issue 5 Pages 442-448
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to clarify the origin of the excellent toughness of 9% Nickel low carbon steels at low temperatures, the change in mechanical properties with particular reference to the notch toughness on the isothermal tempering at various temperatures was investigated in connection with the precipitation of austenite, the change in microstructures, and the fracture characteristics in a 0.1%C 9%Ni steel carefully prepared by vacuum melting. The main results are as follows: (1) The high value of 25∼27 kg-m/cm in the Charpy 2 mm V-notch test is obtained at −196°C in a specimen quenched from 800°C, tempered at 550°C for 20∼60 min and water-quenched. (2) The temper brittleness characterized by the intercrystalline fracture is observed when tempered below 525°C. (3) The intercrystalline fracture is also induced by the segregation of non-metallic impurity atoms such as carbon when a specimen is cooled at slow rates after tempering. (4) The embrittlement characterized by the cleavage fracture observed in specimens tempered above 550°C is ascribed to the precipitated austenite, which is stable even when quenched into liquid nitrogen but by impact can be transformed to martensite; the relation found between the impact value and the amount of austenite does not necessarily support the generally accepted view that the existence of the austenite improves the toughness of this steel. (5) The excellent toughness is achieved by tempering at 525∼550°C at which lattice defects such as dislocations in martensite mostly annihilate, and the coarsening of the precipitated austenite does not occur. The rapid cooling after tempering is also necessary for the good toughness.View full abstractDownload PDF (2137K) -
Masao Kondo, Masumi Osawa, Toru Arai, Shin’ichiro Kumagai1966 Volume 30 Issue 5 Pages 449-454
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNon-metallic inclusions in the quenched samples with the chemical composition of 5%W, 4%Mo, 3%Cr, 1.5%V and 0.6%S were examined by means of microphotography, electrolytic isolation, chemical and X-ray analysis and electron-probe microanalysis. Most of the non-metallic inclusions were the sulphide of MnS type, including an adequate amount of Cr and a small amount of V.
The form of these inclusions is granular or starlike. The colour of these sulphide is almost gray but sometimes includes black spots or white spots. The black spots in the gray sulphide contain a large amount of Al and the white ones seem to be MC type carbide. FeS type inclusions were detected by X-ray analysis. The chemical composition of sulphide isolated by the electrolytic method is approximately Mn:Cr:Fe:S=3:1:2:3 in addition a small amount of V.View full abstractDownload PDF (2604K) -
Naomichi Mori, Sin’ichi Nagashima1966 Volume 30 Issue 5 Pages 455-460
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe self-diffusion coefficients of nickel in the austenitic phase of steels containing 2.5, 3.5, 7 and 9 wt% of nickel were investigated in the temperature range from 900° to 1300°C by the auto-radiographic method with 63Ni as the tracer. Because of the difficulty of grain growth treatment in these commercial steels, the grain size of specimens was only 0.1 to 0.3 mm. Then the volume diffusion coefficient and the grain boundary diffusion coefficient were determined by Suzuoka’s self-consistent method based on the instantaneous source model.
For volume diffusion, the frequency factors were (This article is not displayable. Please see full text pdf.), and the activation energies were 56.8±1.4, 54.9±2.3, 49.4±3.1 and 46.7±1.4 kcal/mole for steels containing 2.5, 3.5, 7 and 9 wt% of nickel, respectively. From these data, the relation between the activation energies and the logarithm of the frequency factors was considered to be linear.
For grain boundary diffusion, neither activation energies nor frequency factors could be correlated with the nickel content. Therefore, the average grain boundary diffusion coefficients for these steels could be represented by (This article is not displayable. Please see full text pdf.) for the frequency factor and 30.9±1.8 kcal/mole for the activation energy, respectively.View full abstractDownload PDF (1781K) -
Hideo Akasu1966 Volume 30 Issue 5 Pages 460-463
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTime-temperature-austenitization diagrams (T-T-A Diagrams) of variously pre-worked 0.73 per cent carbon steels were obtained to provide a guide for rapid heating and quenching operation. The experimental procedure was the same as in one of the previous reports. Experimental results are as follows:
(1) Austenitization of 80 per cent cold-drawn starts and finishes in the shortest time, followed by as-quenched one, 40 per cent cold-drawn one, quenched and 500°C tempered one, and annealed one needs the longest time for austenitization. (2) The above results is related to the fine structure which depends upon the degree of pre-cold-working. Pre-cold-working is effective for rapid heating and quenching.View full abstractDownload PDF (874K) -
Takuichi Morinaga, Shigeo Zaima, Masatsugu Iio1966 Volume 30 Issue 5 Pages 463-469
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSModified aluminium-silicon cast alloy containing about 20%Si, which is called “Alusil” and is not yet standardized in JIS, has been recently exploited and has gradually come to be used for piston or cylinder material. There seems to be some trouble in machining the alusil, because fine plate-like silicon crystals are dispersed within the matrix and therfore their hardness is very high. The cast pistons made of alusil (about 102 mm in diameter) were turned by lathe under the flowing conditions; cutting speed of 100∼800 m/min, depth of cut of 1.0 mm, feed of 0.06∼0.25 mm/rev and various side rake angles of tools were chosen. While the side tool made of sintered hard metal was mainly used, the high speed steel tool was also used. The results obtained are as follows. The tangential component of cutting resistance decreased with the increase in side rake angle. The decreament, however, was comparatively small with in creasing cutting speed and especially so in the case of large side rake angle. The traversing force was equal to or larger than the tangential force in the case of small side rake angle and was not so changeable at the cutting speed of about 400 m/min. At a high cutting speed of 800 m/min, however, it increased rapidly, increasing more distinctly with the rise of side rake angle. The tangential forces for alusil was not so large compared with other aluminium alloys, but the wear of the tool was large, becoming more distinct with the rise of cutting speed. Therefore, very slow cutting speed must be chosen in the case of high speed steel tool. On the other hand, there seems to exist no troubles in connection with cut surface and chip formation.View full abstractDownload PDF (1271K) -
Kazuo Kawamura, Toshio Watanabe, Kôichi Nishizaka1966 Volume 30 Issue 5 Pages 469-473
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSChromized steel is produced by thermal diffusion of evaporated chromium on steel. Therefore, the chromium contents depend on the depth from the surface of the sample. An attempt was made to determine the surface chromium contents of the chromized steel by X-ray fluorescent spectrometric analysis. As excitation potential, 6.5 kV, was used for all measurements so as to generate CrKα, but not FeKα radiation. The sample which has the concentration gradient of chromium, e.g. chromized steel, was not identified with an usual uniform sample. In this case correction is necessary for the sample density and absorption coefficients considering the gradient of the contents. The authors used the following two methods for the correction of the surface chromium contents: One was to employ the intensity ratio of CrKα radiation from chromized steel to that from the uniform sample, and the other was the extrapolation method in which the concentration gradient was considered to be linear. The chromium content used for the above calculation was estimated by using the measured value as the X-ray intensity in the theoretical equation. The concentration gradient of chromium was obtained by measuring the CrKα intensity of the electrolytic ally polished samples. Consequently, for about 0.34%/μ chromium gradient, the surface content should be corrected about 3% up.View full abstractDownload PDF (924K) -
Takashi Sakaki1966 Volume 30 Issue 5 Pages 473-477
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThis experiment was carried out to establish a simple and accurate method for the determination of the tin contents in ferro-tungsten.
The tin was separated from a large amounts of tungsten by the separation method with thionalide, and the separated tin was determined by the spectrophotometric method with stilbazo.
A tin-thionalide complex is formed in 4∼6 N sulfuric acid solutions containing tartaric acid, when the tungsten was dissolved in an ammoniacal solution containing tartarate. By means of this separation method, tin can be separated from a large amounts of tungsten easily and accurately. However, in this condition, copper, bismuth, antimony and certain molybdeniums are co-precipitated with the tin as the thionalide complexes. Among these elements, antimony and molybdenium interfer with the determination of tin by the spectrophotometric method with stilbazo. In this experiment, these elements were separated by the co-precipitation method with beryllium hydroxide.
As a result of the experiment, the author succeeded to establish a method in which less than 0.1% of tin in ferro-tungsten can be measured easily and acctrrately. The tin contents in synthetic and actual samples were measured by this method with satisfactory results.View full abstractDownload PDF (1031K) -
Isoshi Kawashima1966 Volume 30 Issue 5 Pages 477-481
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFor the purpose of carrying out the routine analysis of the powder samples (iron ores, refractory bricks and slags) more efficiently by the fluorescent X-ray analysis, eight elements (MgO, Al2O3, SiO2, S, P2O5, CaO, MnO, T. Fe) in forty basic open hearth slag samples were measured by the loose powder and briquet techniques. The results were compared with those by chemical analysis. It was found that though the loose powder technique could not detect MgO, but by the briquet technique it was detected, and for both techniques the same calibration curves were obtained. The error was less than 10% in both techniques except for MgO and Al2O3.View full abstractDownload PDF (1202K) -
Tatsuro Kunitake1966 Volume 30 Issue 5 Pages 481-487
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe diffusion-in-ferrite controlled model was considered for the concentrating process of carbide-forming elements into cementite during the high-temperature tempering of martensite in low-alloy steels. The degree of concentrating, f(t)=\barCc−Ci⁄Ce−Ci (Ci, \barCc and Ce are the content in a steel, the mean concentration in cementite and the equilibrium concentration in cementite, of the alloying element, respectively), was shown as a function of D (the diffusion coefficient of alloying element in ferrite), a size of cementite particle (a) and etc. in the following expression,
(This article is not displayable. Please see full text pdf.)
\ oindentin which K, K′ and ti were constants determined by the amount of carbide or carbon content of a steel. The application of the present model was successful for the data on the tempering of three Mn-Cr steels in the temperature range from 500°C to 700°C.View full abstractDownload PDF (1742K) -
Noboru Matsumoto1966 Volume 30 Issue 5 Pages 487-492
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen the oxygen content of high-carbon iron containing graphite, such as cast iron, is analysed by the vacuum fusion method, the analytical value is affected by the oxygen adsorption on the surface of the specimen. In the present work, the nature and quantity of the adsorption were studied experimentally. The carbon-saturated iron-melt was prepared in a vacuum furnace. The analytical samples were obtained from the melt by casting in the copper moulds. The oxygen content of the specimens was determined using the vacuum fusion method.
The following results were obtained:
(1) The surface of quenched specimens which contains about 0.5% graphite adsorbes a rather constant amount of oxygen of about 0.0015 cc (NTP) O2/cm2. This amount does not change when the specimen has been preserved in a desiccator for a long period. However, in case of the specimen with 1% graphite, the adsorption increases with increasing preservation time.
(2) The adsorption of the gray iron specimen is more pronounced than that of the quenched specimen and remarkably varies with treatments of the specimen. It seems to be impossible to deduce the oxygen content of the melt from the analytical value of the gray specimen.
(3) Hydrogen adsorption is also observed and a parallelism between the adsorbed quantities of the hydrogen and the oxygen is obtained.
(4) It is suggested that these adsorptions are not a simple adsorption on the specimen surface or by graphite but a thin film formation of rust.View full abstractDownload PDF (1777K) -
Seita Sakui, Tsutomu Kakuma, Tsutomu Mori, Kimiko Satô1966 Volume 30 Issue 5 Pages 493-497
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe stress-strain curve of the dynamic test is higher than that of the static test. This difference would be due to the two factors. First, the mechamism of work hardening at impact differs from that of the static test, resulting in the difference of mecanical properties of specimens. The secondary cause may be the intrinsic strain rate dependence of flow stress in both tests, even if the mechanical properties of both specimens are assumed to be equal.
To check the difference of mechanical properties, the following tests were carried out.
The pure Al polycrystalline specimens were prestrained about 5 to 30% dynamically at room temperature and −196°C, and then tested statically at the same temperatures. The initial flow stress of the former specimens was always greater than that of the latter when compared at a same strain.
The dynamically prestrained specimen showed the so-called work softening in the static test. This phenomenon may be due to a sudden collapse of the work hardened structure established by dynamic prestrain, when the stress is applied statically.
Another extraordinary phenomenon, a remarkable decrease of elongation (tearing off of specimens) accompanying the work softening, was observed and discussed.
The dislocation structures of the work hardened state in both static and dynamic tests were investigated by means of transmission electron microscopy.View full abstractDownload PDF (1229K) -
Kimiyoshi Gotô, Yutaka Ogawa, Eihachirô Tanaka1966 Volume 30 Issue 5 Pages 498-502
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe microstructures of aluminum forged at temperatures from 25° to 600°C and their changes by subsequent annealing have been studied. The initial strain rate was about 440/sec and the working degree varied from 32 to 84%. The specimens were quenched in water within 1.5 to 2.0 seconds after the completion of hot working. The results obtained are as follows:
(1) In the forged specimens there are various grains which are different in the working degree, from scarcely deformed grains to sufficiently compressed ones. The working degree is large and uniform in the middle layer of the specimens, but small and not uniform near the surface.
(2) The recrystallization process was observed for the quenched and annealed specimens. The recrystallized those microstructures were classified into six kinds of grains. When the forging temperature is 450°C or below, the recrystallized grains are not found in the quenched state and appear during the annealing process. It becomes evident that the recrystallization temperature rises with the forging temperature. In the specimens forged at 600°C, the recrystallized grains are observed in the quenched state.View full abstractDownload PDF (2015K) -
The Effect of Temperature and Degree of Working on the Structure of Hot-Rolled and Extruded AluminumYutaka Ogawa, Kimiyoshi Gotô, Eihachirô Tanaka1966 Volume 30 Issue 5 Pages 502-507
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe flow in deformation at high temperature and the microstructures of hot worked aluminum have been studied. Working temperatures were 260° and 450°C in the hot rolling and 200° and 400°C in the extrusion. The specimens were quenched in water within 0.5 to 2.0 sec after the completion of working in each experiment. The results obtained are as follows:
(1) Hot rolling (mean strain rate, 3∼25/sec; reduction, 10∼90%)
The phenomena of center buckling and crown in the rolled plates become remarkable as the rolling temperature and reduction are raised, and finally the wave pattern appears in the central part of the plates. It found that these are caused by the rapid increase in friction coefficient.
(2) When rolling temperature is 450°C, the recrystallized grains are observed in the quenched specimens rolled at high reduction ratio, but not observed at low reduction ratio.
(3) Extrusion (mean strain rate, 4.4/sec; working degree, 98.4%)
The microstructures of quenched and annealed states of the specimens extruded at 200°C are the same as those obtained by cold working. In the specimens extruded at 400°C, recrystallization has occurred in the quenched state, and it seems that there are some differences in the recrystallization process by subsequent annealing between the surface and the middle layers of the specimen.View full abstractDownload PDF (2149K) -
Yôtarô Murakami, Hiroyuki Yoshida, Toshihiko Kawashima, Sa ...1966 Volume 30 Issue 5 Pages 508-514
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of the addition of small amounts of c.p.h. elements on the discontinuous precipitation in Cu-Be and Cu-Be-Co alloys were investigated. The electrical resistivity, micro-vickers hardness and various tensile properties were measured comparing with the results of metallographic examinations during iso-thermal ageing at 350°C and 250°C after quenching from various solution-treatment temperatures.
It was found that the rate and quantity of growth of the discontinuous precipitation at grain boundaries could be estimated from the shape of the curves in which the changes of electrical resistivity of specimens were plotted as a function of ageing time. The addition of Mg, Co or Cd restrained both zone formation and discontinuous precipitation, though the addition of Zn to Cu-Be and Cu-Be-Co alloys accelerated them considerably. When solution-treated at higher temperature, the addition of Fe was also very effective for the retardation. No discontinuous precipitation was found to occur in Cu-Be-Co alloy containing 0.1 at%Mg.View full abstractDownload PDF (2588K)
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