鉄と鋼
Online ISSN : 1883-2954
Print ISSN : 0021-1575
ISSN-L : 0021-1575
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67 巻, 2 号
選択された号の論文の23件中1~23を表示しています
  • 稲山 嘉寛
    1981 年 67 巻 2 号 p. 225-229
    発行日: 1981/02/01
    公開日: 2009/06/19
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  • 飯田 義治
    1981 年 67 巻 2 号 p. 230-244
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
  • 田中 紘一
    1981 年 67 巻 2 号 p. 245-261
    発行日: 1981/02/01
    公開日: 2010/01/18
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  • 伊藤 雅治
    1981 年 67 巻 2 号 p. 262-268
    発行日: 1981/02/01
    公開日: 2010/05/07
    ジャーナル オープンアクセス
  • 澤岡 昭
    1981 年 67 巻 2 号 p. 269-274
    発行日: 1981/02/01
    公開日: 2009/06/19
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  • 金子 秀夫
    1981 年 67 巻 2 号 p. 275-288
    発行日: 1981/02/01
    公開日: 2009/06/19
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  • 福沢 憲一, 高井 明
    1981 年 67 巻 2 号 p. 289-294
    発行日: 1981/02/01
    公開日: 2009/06/19
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  • 金沢 正午
    1981 年 67 巻 2 号 p. 295-302
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    本委員会で提案した焼入性予測の重回帰式は,CおよびC以外の合金元素間の相互作用の有意性を確認し,それらの項を重回帰式にとり入れた点に,最も大きな特徴がある.
    相互作用の物理的意味については,現在のところ明らかではないが,相変熊に関する従来理論に準拠して,その可能性を考えてみる.
    合金元素の添加による焼入性の変化は,オーステナイトの分解過程,すなわち,フェライトあるいはパーライト変態の核生成と成長とに対して,合金元素が如何に機能するかに依存する.
    まず最初に,フェライト変態について考えてみると,Ni, Mn, Si, Cr, Moなどの合金元素は成長の段階でほとんど分配しないことが知られており4),したがつて,これらの元素は,おもに核生成速度を遅らせることによつて,焼入性に寄与していると考えられる.Ni, Mn添加による核生成速度の減少は,熱力学データから推定される理論値に比較的近い5)のに対して,フェライト安定化元素であり,かつ,強力な炭化物形成元素であるMo, Crなどの場合にはほとんど説明できないような核生成現象を示す.したがつて,1つの仮説にすぎないが,従来理論に従わない元素の組み合わせ,あるいは理論に従う元素とそうでない元素の組み合わせのような場合に,相互作用が現れてくるのではないかと考えられる.
    つぎにパーライト変態について考えてみる.この場合に最も重要な点は, Mn, NiはFe3Cに濃縮しないのに対して, Si, Cr, Moは極めて多量に濃縮し,パーライトの成長を遅らせることである.したがつて,フェライト変態あるいはパーライト変態のいずれが支配的であるかによつて,CとC以外の合金元素の組み合わせによる焼入性の関係に差が生じ,このことが,相互作用として現われるのではないかと考えられる.
  • 佐藤 彰, 中川 龍一, 吉松 史朗, 福沢 章, 尾崎 太
    1981 年 67 巻 2 号 p. 303-312
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    Iron oxide pellets being resistant to crushing into pieces on adding onto the iron melt were made from iron oxide powder by pressing and sintering. The melting rate of pellets into iron melt and the reducing rate of pellets by carbon in iron melt were obtained by measuring CO gas evolved. The effects of the kind of iron oxide, oxide additives in pellets, temperature and carbon content of iron melt on the melting rate, and the rate of reduction of solid iron oxides by carbon in iron melt were investigated. The following results were obtained:
    (1) The result using heated pellets showed that the heat transfer was not the rate-determining step. The estimated diffusion layer of carbon in iron melt showed that the carbon transfer could be the rate-determining step. Both the carbon transfer and the chemical reaction were estimated to control the melting and reducing of iron oxide.
    (2) The relation between the total reduction and the time was linear from about 20% to about 70% of the reduction, where solid iron oxides were reduced by carbon dissolved in iron melt.
    (3) The apparent activation energies of melting of pellets into the carbon saturated iron melt were 35 for Fe2O3, 18 and 41 for Fe3O4 above and below 1470°C, and further 44 and 79 kcal/mol for FeO above and below 1470°C, respectively.
    (4) The melting rates of Fe2O3, Fe3O4, and FeO pellets into the iron melt at 1570°C were proportional to the 0.57, 0.45, and 0.42 power of the carbon content in iron melt (wt %), respectively. The minimum volume cf CO gas evelved was obtained at about 2% C.
  • 宮本 学, 尾上 俊雄, 成田 貴一
    1981 年 67 巻 2 号 p. 313-322
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    The complete stress-strain curve for brittle materials cannot be obtained with conventional testing machines because of their low stiffness and difficulties in strain-control. In this paper, the deformation and failure behavior of refractories for blast furnace under strain-controlled uniaxial compression with a stiff testing machine is discussed.
    It is found that the refractories retain some strength and have still appreciable elasticity even after the maximum stress is reached. Fireclay brick shows anisotropy with regard to the stress-strain curve. It has a large deformability and superior resistance to the failure by thermal stress in parallel to the direction of press forming. Carbon brick fractures with a small deformation after the maximum stress. At the temperature above 800°C, fireclay brick exhibits visco-elastic behavior, which is substantially explained by the Burgers model.
  • 丸川 雄浄, 城田 良康, 姉崎 正治, 平原 弘章
    1981 年 67 巻 2 号 p. 323-332
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    As far as we use a blast furnace to produce hot metal, it is most important to control dephosphorization for the improvement of the present steel making process. In view of this, many refining processes to control dephosphorization economically have been studied.
    We investigated the refining process of molten iron by using sodium carbonate, mainly for dephosphorization, and obtained the following results,
    (i) When the sodium oxide type slag is used, the simultaneous dephosphorization and desulfurization occur, because dephosphorization proceeds in spite of its very low total iron content in comparison with the calcium oxide type slag.
    (ii) The degree of dephosphorization is affected by the content of carbon and silicon in molten iron as well as temperature.
    (iii) The prospect for a new steel making process based on the treatment by sodium carbonate depends upon the establishment of a technique to control desiliconization of hot metal, the simultaneous dephosphorization and desulfurization by sodium carbonate, and the development of a sodium carbonate recovery process from the slag.
  • 浅井 滋生, 西尾 信幸, 鞭 巌
    1981 年 67 巻 2 号 p. 333-342
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    In order to decrease center segregation together with center porosity, electromagnetic stirring has been applied to continuous casting of billets, blooms and slabs. As well known, however, the violent agitation in the pool is powerful to prevent center segregation, but promotes the formation of white band.
    To tackle this problem, the laminar and turbulent electromagnetically driven flows in the pool are theoretically analyzed. Especially focusing on the effect of the electromagnetically driven reverse-turn flows on the structure, the solidification experiments are conducted by use of the Sn-10% Pb alloy.
    Theoretical equation of the maximum velocity appearing at every half period for the reverse-turn flow is given as follows:
    υmax2(σω/μ)1/4·√χ0/ρ·B (1-e-1/2fθ), θ=κ3√χ0ρ/{σω/μ1/4B}
    where, B: magnetic current density, κ2, κ3 : constants, χ0 : half thickness of slab, μ: magnetic permeability, ρ: density, σ: electric conductivity, f: cycle of reverse-turn flow.
  • 栗原 極, 荒木 健治, 中岡 一秀
    1981 年 67 巻 2 号 p. 343-352
    発行日: 1981/02/01
    公開日: 2010/01/18
    ジャーナル オープンアクセス
    Aging propcrties of cold rolled high strength steels produced with WQ CAL process (continuous annealing line equipped with a water quenching device) were studied with regard to the factors characterizing these steels such as the second phase (martensite) and a considerable amount of solute C, N atoms in ferrite phase. The results are as follows;
    1. The second phase suppresses the recovery of yield point elongation (YP-El). The extent of this suppression depends on the volume fraction and the hardness of the second phase.
    2. Because of this suppression, no recovery of YP-El is observed until the aging advances to such high degree that the activation energy of aging, determined from the increase in yield stress (ΔYS) or YP-El, is 26 to 30 kcal/mol.
    3. Following consecutive cycles of temper-rolling and subsequent aging (at 170°C for 20 min), discontinuous yielding repeats appearing and disappearing. The solutes C and N decrease distinctively during the first aging treatment and no appreciable change is detected in subsequent treatments.
    On the basis of these results, the reason and the condition for the remarkable feature of these steels, as characterized by the large ΔYS after the BH-treatment (an aging treatment at 170°C for 20 min) and no YP-El after the room temperature aging (simulated by storage at 38°C for 30 days), are discussed. Discussion on the difference in the influence of carbon and nitrogen and the related aging mechanism is also made. Finally overall picture of the aging behaviour of those dual phase steels is proposed.
  • 滝沢 貴久男, 志水 康彦, 米田 英作, 田村 今男
    1981 年 67 巻 2 号 p. 353-361
    発行日: 1981/02/01
    公開日: 2010/01/18
    ジャーナル オープンアクセス
    The effects of cold rolling, heat treatment and volume fraction of ferrite on stress corrosion cracking (SCC) behavior of duplex stainless steel have been studied with means of U-bend method in boiling 42% MgCl2 solution. The main results obtained are as follows:
    (1) SCC susceptibitity of the solution treated material is small at about 50% α, but it has a tendency to be increased with either way of increase or decrease of α content from about 50% α. Solution treatment temperature resulting in abrupt increase of SCC susceptibility shifts to higher temperature with the decrease of α content.
    (2) SCC susceptibility is increased by grain growth of α and γ that occurred with extension of holding time at solution temperature, and otherwise, by cold work in the case of the materials having much volume fraction of α.
    (3) On aging at 475°C, the hardness is increased by spinodal decomposition of α. The crack resistance increases remarkably with the progress of aging in the case of materials having much α, and corresponds to age hardening behavior.
    (4) In the case of heating at 700°C, the SCC behavior of aged materials has not been made clear by U-bend method because of σ embrittlement.
  • 前原 泰裕, 邦武 立郎, 藤野 允克
    1981 年 67 巻 2 号 p. 362-371
    発行日: 1981/02/01
    公開日: 2010/01/19
    ジャーナル オープンアクセス
    The effects of addition of various alloying elements to a steel having base composition (0.1 C-0.3 Si-1.0 Mn) on the static recrystallization in the austenite range have been studied by a high temperature double tension method.
    It was observed that recrystallized grains nucleated at the grain boundaries and that recrystallization time increased linearly with increasing initial grain size. At 900°C, recrystallization after strained to 0.2 by the first tension was retarded by the addition of Si (_??_1.0), Mn (_??_2.5), Ni (_??_1.0), Cr(_??_1.0), Cu (_??_0.3), Nb (_??_0.04), V (_??_0.1) and Mo (_??_0.4). Among them the retardation effect of Nb was remarkable, and this was explained by precipitation of NbC. On the other hand, the role of other elements in the retardation was ascribed to substitutional solid solution effect. In the Nb added steel, the degree of retardation was found to be significantly influenced by the heating history before a double tension test. This can be explained by the difference in the dispersion of NbC precipitates in addition to the initial grain size. The contribution of individual effect of grain size or precipitation on recrystallization was separated in an analytical way. Recrystallization rate increased with increasing C content (0.0020.07), but this was interpretated as due to the indirect effect of initial grain refinement by carbon.
  • 笠原 晃明, 磯脇 剛
    1981 年 67 巻 2 号 p. 372-381
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    Hydrogen stress cracking (HSC) susceptibility of various line pipe steels was evaluated by means of a slow strain rate technique (SSRT) as well as a conventional static load technique (SLT). Effects of strain rate, temperature, pH, applied potential, applied cathodic current density and hardness on the HSC susceptibility were made clear. The results obtained are summarized as follows:
    (1) The results obtained by SSRT were quite analogous to, but more quantitative than those obtained by SLT. SSRT was proved to be quite a pertinent technique to evaluate the HSC susceptibility of line pipe steels being classified into go or no-go categories.
    (2) The HSC susceptibility depended on the strain rate with highest in the strain rate region of 10-6 and 10-7 sec-1 and decrease in the higher strain rate region.
    (3) The HSC susceptibility depended on the applied potential increasing with cathodic polarization.
    (4) The HSC susceptibility increased markedly with increasing current density of up to 2 mA/cm2, but was almost constant and highest in the region over 2 mA/cm2.
    (5) The HSC susceptibility was not affected by pH in the pH range between 4 and 12, while increased markedly with decreasing pH values of less than 4.
    (6) Hardness was a vital factor ihfluencing the HSC susceptibility of line pipe steels. The critical value, below which the steel would be free from HSC, for each line pipe steel was Hv=260 for API Spec 5LX-X65CR and QT, 265 for X60CR, 220 for X42 and 240 for JIS STPY-41.
  • 藤田 春彦, 田中 学, 神谷 修
    1981 年 67 巻 2 号 p. 382-390
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    The fracture toughness of four kinds of structural steels with relatively high elongation at room temperature has been evaluated by the electrical potential method and by other methods between at room and liquid nitrogen temperature. The results obtained are summarized as follows:
    (1) At room temperature, (JIC) E value by the electrical potential method was very close to ( JIC) R value by the R curve method. ( JIC) S value by the SZW method was 15% higher than ( JIC) E value.
    (2) At room temperature, the crack initiation detected by the inflection of the electrical potential corresponded to the stage where the formation of type II dimple and the internal necking occurred. Before the crack initiation, voids were already formed in front of the stretched zone.
    (3) JIC value increased with decreasing the testing temperature because of an increase in the yield strength, while it decreased drastically when cleavage fracture occurred at the precrack tip.
    (4) JIC value, CTOD (δ) and KIC were related with each other as follows:
    JIC=1.79δy·δ (for ductile fracture)
    KIC=0.81√JIC·E (for brittle fracture)
  • 堤 信久, 竹内 力
    1981 年 67 巻 2 号 p. 391-398
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
    An investigation has been made of the effect of cooling rate from both 450 and 650°C and also the effect of treatments consisting of various combination of heating rate, holding temperature and cooling rate on the shift of transition temperature of blackheart malleable iron by impact test. IMA analysis has been also carried out on the fracture surface of specimens cooled from 450°C under the various cooling conditions.
    The results obtained are as follows:
    (1) Holding at 650°C or slow cooling from 450°C shifts the transition temperature to lower temperatures.
    (2) Q uenching from 450°C increases the tendency of embrittlement.
    (3) Any heat treatment have no effect no the transition temperature when cooled from 650°C after 0.5 h. holding.
    (4) The influence of cooling fate from 650°C to room temperature on the embrittlement of blackheart malleable iron is almost the same as that in the temperature range from 650°C to 450°C.
    (5) IMA analysis on the fracture surface of blackheart malleable iron cooled from 450°C with various cooling rate shows that the larger the cooling rate is, the higher the phosphorus concentration on the fracture surface becomes.
  • 古川 敬
    1981 年 67 巻 2 号 p. 399-405
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
  • 鉄鋼の歴史のトピックス (2)
    羽田野 道春
    1981 年 67 巻 2 号 p. 406-408
    発行日: 1981/02/01
    公開日: 2009/06/19
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  • 徳田 昌則, 佐久間 健人
    1981 年 67 巻 2 号 p. 408-408,410
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
  • -Improving Transactions of the ISIJ-
    草鹿履 一郎, 小野 桓司
    1981 年 67 巻 2 号 p. 415-419
    発行日: 1981/02/01
    公開日: 2009/06/19
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  • 紫冨 田浩, 斎藤 典生, 小松 周作, 虎岩 清, 竹内 秀次, 大沼 啓明, 郡司 好喜, 新村 哲生, 中島 宏興, 三宅 英徳, 青 ...
    1981 年 67 巻 2 号 p. 420-425
    発行日: 1981/02/01
    公開日: 2009/06/19
    ジャーナル オープンアクセス
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