日本金属学会誌
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
25 巻, 12 号
選択された号の論文の16件中1~16を表示しています
  • 沼倉 健一
    1961 年 25 巻 12 号 p. 751-754
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The order-disorder transformation of hot-rolled “Alfer” sheets with 12.29 and 13.41 per cent of aluminum was studied. The results are summarized as follows: (1) The saturation magnetostriction of Alfer of 12.29 per cent aluminum composition in the ordered state after water quenching from just below critical temperature of order-disorder transformation was very close to that in the state after subzero quenching in liquid nitrogen from higher temperature than the critical temperature. (2) Under the same heat treatments as mentioned above, the young’s modulus of this specimen was largest in the disordered state quenched in water, next in the ordered state quenched in water, and smallest after subzero quenching in liquid nitrogen. (3) The intensity of magnetization of this specimen at H=50 Oe in disordered state was smaller than that in ordered state. (4) The intensity of magnetigation of this specimen at H=50 Oe, was somewhat dependent upon roll direction and showed a maximum at 45° to the roll direction. The property of specimen of 13.41 per cent aluminum composition was different from that of the above specimen in some measurements because of the complexity of phase change.
  • 沼倉 健一
    1961 年 25 巻 12 号 p. 754-758
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The change of magnetostriction and Young’s modulus of hot-rolled “Alfer” sheets, quenched in water and then subjected to heating cycles of one minute heating followed by air cooling at 300°, 400°, 500°, and 600°C were studied. The saturation magnetostriction increased abruptly at the initial step of heating time except at 300°C, and the tendency of the increase was the sharpest at 500°C, sharper at 600°C, and gentle at 400°C. All the specimens showed a distinct maximum at 500°C. The saturation magnetostriction in 45° direction showed a clear two-step variation at 400°C run. The change in Young’s modulus with heating time showed two different tendencies: (A) the young’s modulus decreases to a minimum, then increases to a maximum, and then decreases again; (B) the modulus gradually falls to a constant level. In 500° and 600°C process, the Young’s modulus in 45° direction of A·F-2 specimen (1 mm in thickness) showed abnormal change, and increased to a maximum and then decreased.
  • 沼倉 健一
    1961 年 25 巻 12 号 p. 758-761
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The magnetostriction and the magnetization of 10 kinds of polycrystalline ferromagnetic iron-aluminum alloys after various heat treatments were measured. The magnetostriction curve of Fe-Al alloy containing 2.39 per cent of aluminum showed a minimum near saturation when it was heated for one hour at 1200°C, and quenched in water from that temperature. The magnetostriction curve of Fe-Al alloy containing 8.43 per cent of aluminum was quite peculiar and showed irreversible hysteresis, just after heating for one hour at 300°C, then quenching in liquid nitrogen from that temperature. A maximum of saturation magnetostriction appeared at the composition of about 12 per cent of aluminum, and this tendency did not change by heat treatments. Furthermore ,the deviation of saturation magnetization with each heat treatment was largest at the above composition because of order-disorder transformation. The saturation magnetostrictions of the alloys in the composition range, except ordered phase, quenched in water from 1200°C, were larger than that in the state cooled in furnace from the same temperature.
  • 織田 貞四郎, 植田 昭二, 中村 誠
    1961 年 25 巻 12 号 p. 761-766
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    Although many of the phenomena associated with the intercrystalline corrosion of austenitic stainless or heat resisting steels depending on the precipitation of carbides at grain boundaries have gradually become clarified, little detailed investigation of the quantitative measurement on the chromium concentration of depleted zone adjacent to the grain boundary has been made hitherto. This report summarizes some of the works on the concentration of chromium-depleted zone which has been investigated from the relationship between the variation of the potential of austenitic steel with applied cathodic current and the change of width of boundary groove that was measured by electron microscopy. It was concluded that the concentration of chromium in the advancing interface with the carbide precipitate growing in an austenitic grain-boundary is less than about 1 pct.
  • 渡辺 十郎
    1961 年 25 巻 12 号 p. 766-769
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The effects of sulfides on the high temperature strength of the twelve 3%Ni-Mo-V steels having four different sulfur contents and subjected to forging at three different rates were studied. The test results were as follows: (1) The creep-rupture strength (plain specimen) at 500°C was not affected by sulfides, but the steels which contain 0.048 and 0.090%S ruptured showing low ductility. (2) Sulfides have the similar effect on the strength against the cyclic thermal stress as on the tensile ductility, and the crack depth observed by the author’s cyclic thermal stressing method has the following relation to the fracture ductility,
    (This article is not displayable. Please see full text pdf.)
    where hmax: maximum crack depth measured after 1000 cycles (mm), εf: fracture ductility.
  • 渡辺 十郎
    1961 年 25 巻 12 号 p. 769-773
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The effect of non-metallic inclusions on the anisotropy of tensile ductility of low-alloy steels having the tensile strengths lower than 100 kg/mm2 was studied. The test results were as follows: (1) Beyond the tensile yielding stress many micro-cracks were formed at the extremities of the inclusions and the size and the distribution of these micro-cracks were responsible to the anisotropy of the ductility. (2) when the specimen was taken from the heavily segregated region, many inclusions were contained and even the tensile strength was lowered by these inclusions. (3) the anisotropy of the reduction of area of twelve 3%Ni-Mo-V steels, having four different sulfur contents and subjected to forging of three different rates, was increased proportionally to the sulfur content and the forging rate, but the anisotropy of the segregated region may be influenced by the segregation of not only sulfur but also the other alloying elements.
  • 長谷川 正知
    1961 年 25 巻 12 号 p. 773-776
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The iron surface prereduced by hydrogen was oxidized to give rise to interference colors, and was observed with a microscope. The interference color of each grain surface is uniform in its boundary, but the colors differ from each other. After a specimen was oxidized at 400°C, it was once reduced and oxidized again to the same extent at 265°C, and the colors of the same part of the surface in these two cases were compared. It was found that a certain pair of grains interchanged the color with each other. These results would suggest that the rate of growth of the oxide film differs with the crystallographic direction of the grain surface, and that one grain of the pair showing a larger rate at 400°C shows a smaller rate at 265°C. The above result shows that not only the activation energy of the reaction differs in each grain surface, but also the frequency factor of the rate constant is also different in each grain surface. Assuming that the growth of the oxide film obeyed the parabolic law at either temperature, the author calculated, as an example, the difference of the activation energies and the ratio of the frequency factors of the reactions on two grains which showed a comparatively marked color difference. They are 4.3 kcal/mol and 39 respectively. The fact that the color differs in each grain has not been taken account of, in previous works, in estimating the thickness of oxide film by means of the interference color. The author examined the method of estimating thickness by comparing (1) the thickness estimated from the overall color, (2) the average thickness obtained from the color of each grain and its area, and (3) the thickness calculated from the amount of absorbed oxygen.
  • 諸住 正太郎, 幸田 成康
    1961 年 25 巻 12 号 p. 777-781
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    Flake-beryllium lump melted and solidified in a beryllia crucible in vacuum was cut, polished, and ethced with hydrochloric acid. Regular- and irregular-shaped etch pits and a characteristic striated structure were observed. The regular-shaped pits were needle-shaped, rectangular or hexagonal. Stereographic projection analysis, using the back-reflected X-ray patterns and microphotographs of twins and slip lines on the surface of specimens, indicated that the grain surface with hexagonal pit corresponded to the (0001) basal plane, that the sides of the hexagon were parallel to the a-axes, that is, were formed by intersection of (0001) and {10\={1}0} planes, and that the striation is the intersection of {10\={1}0} prismatic planes. Therefore, it was deduced that the major exposed plane by etching, e.g. the facet of rectangular pit, is one of {10\={1}0} planes and the minor one is (0001) plane. As etching proceeds, the etched area of the grain surface which was favorably oriented to produce the striated structure propagated more rapidly than that of other grain surface.
  • 小田 仲彬, 井戸原 満, 塚島 清
    1961 年 25 巻 12 号 p. 781-785
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    In the process control and technical improvement of the ferrosilicon metal industry, speeding up of the determination of Al in ferrosilicon products has been a foremost requirement. For these purposes, the wet chemical analysis is tedious and lacks the rapidity required. In order to solve these problems, a quantitative spectrographic determination of Al in ferrosilicon metal was studied with some statistical techniques. The following factors were investigated in this study; excitation sources, shape of electrode, internal standard-buffer, parameters of intermittent a.c. arc, factors in the sample preparation and analytical operation, and sample quantity in sampling. The outline of the method obtained from the results of the experiments was as follows; a sample of ferrosilicon powder (500 mg) is mixed with the previously prepared internal standard-buffer (750 mg) (C:BaCl2·2H2O=2:1), loaded into the lower cup electrode and arced for 20 sec in an intermittent a. c. arc (interm. ratio 1/20, interm. No. 1 time/sec., resistance 20 Ω and exposure time 20 sec). The analytical line pair was Al I 3082 Å-Ba I 3072 Å. By this method, ferrosilicon samples could be analysed in 3 hours with the precision of about 6% in terms of coefficient of variation. The concentration range of Al investigated in this study was 0.1∼2.0%, but a little modification might extend this range.
  • 前田 繁男
    1961 年 25 巻 12 号 p. 786-790
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    An examination was carried out by the X-ray diffraction microscopy with respect to misoriented sub-structures in the crystals which had been grown from the melt in the [001] direction. It is found that within the range of the lowering speed from 1 to 10 mm/min, the specimen consists of the two types of sub-structure whose boundaries extend together in the direction parallel to the [001] axis. One type of sub-structure is that which is termed “striations” and the other is the sub-structure, developed by branching off of sub-boundaries during the growth. A mechanism of the latter formation is discussed on the basis of the fact that super-cooling liquid exists inside the groove which is formed at the solid-liquid interface meeting the sub-boundary.
  • 田辺 良美, 高本 信次郎
    1961 年 25 巻 12 号 p. 790-795
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    With an electron microscope, the present authours have studied the behaviour of precipitates in the case of aging of 0.018%C iron and 0.08%C steel at 50°C. In the age-hardening curve, two steps were observed. The first step appeared between 3 hr and 4 hr aging, and the second step (peak) was observed in the specimen aged for 20 hr. From this experimental results and electron microscopic observations, the authours have concluded as follows: (1) The precipitation phenomenon began from the first step and the rise of hardness before 3 hr aging might be due to the G.P. zone. (2) The precipitation periods in which the disk-like precipitates of about 130∼200 Å were precipitated alone, were continued untill 14 hr aging. (3) In the second step (20 hr aging), the precipitates were not precipitated in largest quantity in each crystal grain. (4) In the 50 hr aging, the low concentration zone of precipitates were grown to about 1000∼1700 Å in breadth along grain boundary as Photo. 11 on some occasion, and in the slip bands, the precipitates of about 150∼350 Å were precipitated perferentially upon the slip lines. (5) The tendency of the site of precipitation generally took the following sequence: The grain boundaries, the vicinity of boundaries, the slip bands and then the whole surfaces in each crystal grains. (6) The disk-like precipitates of about 130 Å were grown to the extent of about 200 Å as the disk-like shape by the process by which the solute atoms are coagulated to precipitates. (7) The disk-like precipitates were thought to solidify again in matrix with the lapse of aging time, and then the spherical precipitates were problably precipitated anew from its matrix. (8) The spherical precipitates when grown to about 300 Å, coalesed with each other and then grew into the large spherical precipitates. (9) In the crystal grain, the large plate-like precipitates formed by coalescence of spherical precipitates were almost never observed, but were observed slightly in the grain boundaries and its vicinity. (10) In the 8760 hr(1 year) aging, precipitates were observed abundantly on the whole surface of every crystal grain, and the specimen’s hardness was rose to a value higher than the highest value in 70°C aging. (11) The size of the precipitates was not taken constant size in the specimen which was aged for some aging time, and there was coexistence in the precipitates of various size. (12) In the grain boundaries which appeared the low concentration zones of precipitates, were observed the disk-like precipitates. (13) The precipitates were thought to consist of iron carbide.
  • 加藤 栄一
    1961 年 25 巻 12 号 p. 795-798
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    Various sampling methods for determination of hydrogen in molten cast iron (2.63∼3.41%C, 1.40∼1.88%Si) have been compared. The samplers used were the vacuum sampler, the modified Taylor sampler, the silica tube and two kinds of copper moulds (6×6×65 mm, 15 mm dia. by 75 mm long). After solidification the drawn or poured iron was quenched in mercury. Among these samplers, the vacuum sampler is most complicated, but it seems to be most reliable. The hydrogen in the samples was extracted by the hot-extraction technique at 1000°C, and determined by the palladium-tube method. The results obtained were as follows: (1) When the hydrogen content is less than 8 p.p.m., the results obtained with the vacuum sampler coincide with those obtained with the modified Taylor sampler. The values obtained with the copper moulds are a little lower than those obtained with the two samplers mentioned above. The values obtained with the silica tube agree fairly well with those obtained with the modified Taylor sampler when the iron contains up to 3 p.p.m. of dissolved hydrogen, but when the hydrogen content is larger, the silica tube methods gives considerably lower hydrogen content than that obtained with the modified Taylor sampler. (2) The standard deviation of the results obtained with the modified Taylor sampler is 0.23 p.p.m. within the range of hydrogen content from 1.7 to 3.4 p.p.m.
  • 泉山 昌夫
    1961 年 25 巻 12 号 p. 799-803
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    The martensite transformation of over-aged retained austenite was investigated using nickel steels. The martensite transformation showed the complicated changes by aging. These changes consist of four stages (see Fig. 1). The lowering of Ms′ point in the 1st stage is caused by the stabilization of retained austenite. The rising of Ms′ point in the 2nd stage is caused by the stress relaxation due to martensite decomposition during aging. The lowering of Ms′ point in the 3rd stage is caused by the increase in the martensite-austenite interfacial free energy because of the lowering of carbon content in martensite and the concentration of these partial carbon atoms at the martenite-austensite interface during aging. The lowering of Ms′ point in 4th stage is caused by the stabilization of retained austenite due to partial transformation to martensite during cooling from the aging temperature.
  • 塚本 冨士夫, 原田 憲二, 金子 智
    1961 年 25 巻 12 号 p. 803-807
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    Influence of 475°C embrittlement of high-Cr ferritic steels on their corrosion resistances was investigated mainly by potentiostatic method. The results obtained are summarized as follows: (1) Materials aged at 475°C do not lose in the corrosion resistance in active state and have a tendency to gain it more than the annealed materials. (2) The Flade potential of materials aged at 475°C is less noble by 0.1 to 0.15 V than that of the annealed materials. The critical current density for passivation is decreased by aging treatment 475°C. (3) The resistance to intergranular corrosion is decreased by aging treatment at 475°C. (4) In over-passive state, the anodic current has a tendency to decrease by aging treatment and a secondary passive state is clearly observed. (5) These changes are observed most clearly at 475°C and are apparent in proportion to the length of aging time at 475°C. (6) These corrosion behaviors of 475°C aging materials can be well explained by postulating a Fe3Cr-type superlattice.
  • 塚本 冨士夫, 矢ヶ崎 汎
    1961 年 25 巻 12 号 p. 807-811
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    High-Cr ferritic steels do not show a clear yielding phenomenon on room temperature tensile test after proper heat treatment, although dislocation locking by C and N atoms is expected in such a body-centred cubic metal as indicated by Cottrell and others. Because this is attributed to the strong chemical affinity of C and N to Cr, it might be well anticipated that the yielding phenomenon will be observed when these steels increase their internal stress by plastic deformation or by quenching from sufficiently high temperature and then being subjected to aging treatment at relatively lower temperatures. Thus at first, the existence of the above mentioned strain-aging phenomenon was confirmed by tensile test of AISI Type 446 steels. A specimen strained 5% in length showed a clear yielding after heating only for 20 min at 200°C while no singularity appeared in the stress-strain diagram of that treated at 100°C up to 100 hr. Then the effect of interstitial atoms such as C and N and that of Cr were investigated. The results revealed that nitrogen is more effective on strain-aging than carbon and that the yield point is more perceptible when the Cr content is increased up to 35%. Although no quench-aging was observed on the specimen quenched in water from 1200°C and aged for 100 hr at 200°C but the specimens air-cooled from 750∼1000°C showed a flattening of stress-strain curve or even a yielding on room temperature tensile test. The hardness increased also by strain aging. In this case, the increase was observed even after an aging at 100°C on specimens prestrained more than 5% in length. Highly strained specimens showed larger increase which completed within an hour and a softening due to overaging is observed by longtime aging at 300°C. The impact test of cold rolled and aged specimens disclosed the fact that the brittle-ductile transition temperature shifts to the higher side and consequently a remarkable embrittlement was observed on the impact test below 50°C. No structural change has been observed on microscopic examination of strain-aged specimens.
  • 塚本 冨士夫, 鈴木 隆志
    1961 年 25 巻 12 号 p. 811-815
    発行日: 1961年
    公開日: 2008/04/04
    ジャーナル フリー
    High-Cr ferritic steels such as AISI Type 446 stainless steel may have a duplex structure of α+γ at elevated temperatures, depending on their chemical composition, which variously influences their high temperature physical and mechanical properties. In this study, the effects of alloying elements on the α/α+γ transformation and the behavior of “veining” structure in ferrite grains of high Cr steels were investigated, the results of which may be summarized as follows: (1) C and N lower slightly the α/α+γ-transformation temperature of Type 446 steel. Ni also lowers that transformation temperature, remarkably while Si raises it. (2) In low-C steels, the γ-phase increases notably and then decreases gradually as the temperature rises over the transformation temperature, while, in the high-C steels, the γ phase is not changed nearly at all by the temperature. (3) The linear relation between the effective Cr percent and the heating temperature as reported by Post and Eberly was not found but and a somewhat new relation was found. This inconsistency may be attributed to the change in diffusion velocity at elevated temperatures. (4) The “veining” structure observed in 25%Cr steels having more than 0.03% of C+N appears by water cooling from high temperatures, say over 1100°C. This structure is more clear as the heating temperature is higher and the heating time is longer but it does not appear after slow cooling. It is not visible near the ferrite boundaries but visible only inside of ferrite grains. It agglomerates by reheating at 550° to 650°C. It is proposed that the origin of the veining structure of high-Cr steels is precipitates of carbide and/or nitride produced by reduction of the solubility of C and/or N during rapid cooling from high temperatures or prestage of the precipitation accompanied by high internal stress.
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