鉄と鋼
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
48 巻, 2 号
選択された号の論文の11件中1~11を表示しています
  • 俵 信次
    1962 年 48 巻 2 号 p. 103-104
    発行日: 1962/02/01
    公開日: 2010/02/22
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  • 溶鋼温度の連続測定について-II
    小野寺 真作, 荒木田 豊, 平岡 昇
    1962 年 48 巻 2 号 p. 105-111
    発行日: 1962/02/01
    公開日: 2010/02/22
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    In the first report (Tetsu-to-Hagané, 47 (1961) 11, p.1982-1988), the authors described the continuous immersion pyrometry method of molten steel in ladle and some results thereof. In order to establish this method, it was neccessary to keep the degree of contamination of thermocouple elements as low as possible.
    To obtain high accuracy of actual measurement, the contamination of every thrmocouple wires used for each measurements is studied by the measurement of the drop of e. m. f., the examination of the distribution of parasitic e. m. f. and the spectrographic analysis etc. And, the tentative method to caluculate the error which was appearing during the actual measurement was considered. The main results obtained by these studies were as follows:
    (1) Value of parasitic e. m. f. on the PtRh element is positive. This seems to be the characteristic of the contamination for this case.
    (2) The error which is appearing during actual measurement can be caluculated by the next formula:
    ΔT=Σi {ΔT1 (EPt1-EPtRh1) /1000F1}
    (3) The degree of contamination of thermocouple elements depends on a temperature distribution along the wire, diameter of the wire, the insulating and protecting tube.
    (4) To attain to the lower degree of contamination on the thermocouple elements and the lower cost of measurement, it is better to use a wire of smaller diameter.
    (5) It is desirable to avoid the successive use of thermocouples for a high-accuracy measurement.
  • 今井 光雄, 大井 浩, 江見 俊彦
    1962 年 48 巻 2 号 p. 111-117
    発行日: 1962/02/01
    公開日: 2010/02/22
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    The solubility of hydrogen in a synthetic and basic open hearth steelmaking slags of molten lime-silica-iron oxide system has been determined experimentally.
    The hydrogen absorption of these slags is rapid. After the beginning of reaction, the twothirds of the equilibrium hydrogen is absorbed within ten minutes, and only one hour is necessary to reach equilibrium. The solubility of hydrogen in slags is increased in proportion to the square root of the partial pressure of water vapour in the atmosphere with which slag stands in equilibrium, and also is increased with rising reaction temperature. The heat of solution of water vapour into slag is about 13kcal/mol.
    The effect of slag basicity on hydrogen solubility is remarkable. In the range CaO/SiO2 greater than unity, solubility is increased linearly with rising basicity. The solubility reaches the minimum when CaO/SiO2 is equal to unity, and in the range CaO/SiO2 less than unity, is increased again with falling CaO/SiO2. But, when slag contains much amount of iron oxide, the solubility does not increase in the range CaO/SiO2 less than unity.
    Comparing the experimental results of synthetic slag studies with results from industrial heats, a good coincidence has been obtained.
  • セミキルド鋼についての研究-III
    加藤 健, 今井 純一, 梶岡 博幸
    1962 年 48 巻 2 号 p. 117-123
    発行日: 1962/02/01
    公開日: 2010/02/22
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    Numerous black spots are usually observed on sulphur prints along the skin layers of semi-killed steel ingots, which probably may develop into surface defects under severe processing of semi-killed steel products.
    Using 10 ton slab ingots, investigations were carried out into the effects of deoxidizers on these black spots.
    The main results obtained are as follows:
    (1) The substances of these black spots consist of crowds of sulphides to be accompanied with blow holes and of large silicates, the greater part of which contains some sulphides.
    (2) These black spots can be reduced by using aluminium as the main deoxidizer instead of silicon, although this result may be also attained by the decrease of sulphur content of molten steel.
    (3) The large silicates have mnch relations with ladle refractories. When silicon is used as deoxidizer, it can catch a greater amount of oxygen, as the temperature of molten steel drops during the period from tapping to solidifying, whereas in case aluminium is used, the content of residual aluminium in molten steel cannot be expected to be high because of its strong deoxidizing power to combine with more oxygen while cooling. It is presumed, therefore, that in order to get the same condition of blow holes in ingots, the oxygen content of molten steel in ladle should be lower, and accordingly the ladle refractories are the less damaged when aluminium is used as deoxidizer than when silicon is used.
  • 岡本 正三, 田中 良平, 藤本 六郎, 内藤 武志
    1962 年 48 巻 2 号 p. 123-133
    発行日: 1962/02/01
    公開日: 2010/02/22
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    An experimental study was made on the fundamental phenomena occuring in melting and casting of various high-chromium steels in high-pressure nitrogen atmosphere and on the influence of nitrogen content on heat-resisting properties of type 316L steels. It was confirmed that the solubility of nitrogen in the type 316L steel melted at about 1550°C in nitrogen atmosphere up to 10 atm obeys the Sieverts' law, and was represented by the following equation:
    %N=0.183 (PN2) 1/2
    The high-pressure melting was also c1arried out for such steels as 10-25%Cr-20%Ni-Fe alloys, 17-4PH type stainless steels containing 0.5% or 3% of Si, 18%Cr-4%Ni stainless steels, 18%Cr-8%Mn stainless steels, 22%Cr stainless steels containing O or 2% of Ni and LCN-155 alloys, and the effects on ingot soundness of nitrogen contents, melting conditions, casting conditions and of the sort of the phase formed in process of solidification, were discussed in detail. Further, it was confirmed that the nitrogen contained in these ingots did not diffuse out from the steel unless it was heated to high temperatures in high vacuum.
    It was observed also that the nitrogen raised the strength of type 316L steels at both room and high-temperatures, the ductility at high temperatures dropped considerably and high temperature creep-rupture strength of the steels showed the maximum at a nitrogen content of about 0.33%.
  • 堀川 一男, 梅沢 義信
    1962 年 48 巻 2 号 p. 134-142
    発行日: 1962/02/01
    公開日: 2010/02/22
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    After having carried out the “Metallurgical Investigation into Ancient Iron Nails” (Tetsuto-Hagané 48 (1962), No. 1, pp. 44-49), the authors have made metallurgical investigation successively into the ancient iron wares such as clamps, rivets, ornamental fittings used in “Hôôdo” (main hall) of “Byôdô-in” temple, three-storied pagoda of “Meitsûji” temple and five-storied pagoda of “Daigo-ji” temple. Results obtained are summarized as follows.
    (1) Manufacturing process,
    Chemical compositions, nonmetallic inclusions and hardness are almost the same as those of the ancient nails, excepting two or three specimens made in a later period which have shown high P content.
    (2) As to the cast iron product, the C content is somewhat higher and the P is somewhat less than cast iron used at present. The Si, Mn and S are noticeably low.
    (3) Correlation of the quality of specimens and the age of their manufacture could not be grasped clearly, because there were a considerable dispersion of data between specimens manufactured in the same age. Nevertheless it seemed reliable that the older the manufactured age, the higher the purity is.
  • 構造用低合金鋼の研究-II
    西原 守, 中野 平, 牧岡 稔, 後藤 督高
    1962 年 48 巻 2 号 p. 143-148
    発行日: 1962/02/01
    公開日: 2010/02/22
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    In the previous paper (Tetsu-to-Hagané vol. 48, (1961), 1, pp. 34-38) effect of increasing of Ni, Cr, Mo and V, and decreasing of C content to the hardenability of Ni-Cr-Mo steel (SNCM 8: SAE 4340) was reported.
    In this paper, by using the same test materials and the same quench-cooling rate, as those in the, previous paper, the mechanical properties in as-tempered condition were examined in connection with their alloying elements. The test specimens quenched at 4 different cooling rates were tempered at appropriate temperature so as to obtain as-tempered strength of 80 to 130kg /mm2. Then a comprehensive study was made on temper-softening tendency, tensil property and notched impact property at room temperature (20°C) and -40°C. A study on sensitivity of temper-embrittlement was also performed.
  • 小野 健二, 根本 正, 佐々木 良一
    1962 年 48 巻 2 号 p. 148-155
    発行日: 1962/02/01
    公開日: 2010/02/22
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    The present study was carried out to make clear the effects of solution treatment on the creep rupture properties of type 321 stainless steel.
    To prepare test pieces, three kinds of stainless steel bars, 17Cr-9Ni, 17Cr-9Ni-Ti and 18 Cr-11Ni-Ti with 25mm diameter were reduced to 15mm diameter by “hot-cold working” at 500°C after water-cooling from 1050°C. And then these specimens were solution-treated at various temperatures between 800°C and 1200°C for 1 hour. Some of these were reheated at 1000°C for 2 hours, 900°C for 5 hours and 800°C for 100 hours after water-cooling from 1100°C.
    The obtained results were summarized as follows.
    (1) Low-temperature heat-treated material had very fine grains and a low rupture strength. However, with increase of solution temperature it showed coarser grains and a higher strength. but a decreased rupture elongation. In general, rupture elongation of 18Cr-8Ni steel was larger than that of 18Cr-8Ni-Ti steel.
    The effect of solution-treating temperature on the creep rupture strength of 18Cr-8Ni-Ti steel was very larger than that of 18Cr-8Ni steel.
    (2) With the 18Cr-8Ni-Ti steel which had been water-cooled or furnace-cooled from 1100°C, reheated at 1000°C and 900°C after solution treatment at 1100°C, there was a considerable difference among their carbide precipitation in microstructure, although there was little difference among their creep rupture strength. Specimens which had been reheated at 800°C for 100 hours after water-cooling from 1100°C, showed a lower creep rupture strength than that of water-cooled specimens.
    (3) It is presumed that the variation of strength with solution-treating temperature and time was related to both grain size and solubility of carbide.
  • 青木 宏一, 関野 昌蔵, 藤島 敏行
    1962 年 48 巻 2 号 p. 156-176
    発行日: 1962/02/01
    公開日: 2010/02/22
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  • 下村 泰人, 河合 重徳, 上正原 和典, 安原 四郎, 邦武 立郎, 河野 拓夫, 若松 茂雄, 小泉 秀雄, 田中 実
    1962 年 48 巻 2 号 p. 177-182
    発行日: 1962/02/01
    公開日: 2010/02/22
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  • 1962 年 48 巻 2 号 p. 185-186
    発行日: 1962/02/01
    公開日: 2010/02/22
    ジャーナル オープンアクセス
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