巻号一覧
61 巻, 2 号
選択された号の論文の8件中1～8を表示しています
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清水 哲也, 岡部 道生, 飯久保 知人1990 年 61 巻 2 号 p. 85-92
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーThe localized corrosion resistance of 18 stainless steels with high molybdenum and nitrogen has been investigated. As long as stainless steels include over a certain amount of chromium content, e.g., 16wt% in this work, pitting index (Cr+3.3Mo+16N) is given to correlate well with localized corrosion resistance of stainless steels including molybdenum content up to 11wt%. There was a good correlation with depassivation pH and the crevice corrosion field test in natural seawater for one year.抄録全体を表示PDF形式でダウンロード (2008K) -
附田 賢治, 岡部 道生, 飯久保 知人, 磯部 晋1990 年 61 巻 2 号 p. 93-101
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーAlthough it is expected that mechanically alloyed oxide dispersion strengthened (MA·ODS) Ni-base superalloys have enough creep strength at even ultra-high temperature near to solidus, no investigation has been done on it. Accordingly compressive creep strength and stability of dispersoids of MA·ODS Ni-base superalloy, MA 758, at 1523 to 1623K were investigated, and following results were obtained.
(1) Steady-state creep rate(εs) and stress exponent (n) were different between transverse and longitudinal direction; εs of transverse is about one eighteenth of one of longitude, and n of those directions were 6 and 2.1 respectively at 1573K under 15 to 125MPa.
(2) Values of apparent activation energy for creep obtained for the transverse and the longitudinal were 115.1 and 133.0kcal/mol respectively which are about twice as large as one of Ni for self diffusion.
(3) Fracture modes of creep rupture were also different between the transverse and the longitude; fracture of the former was occured by slipping between longitudinal boundaries of elongated grains and following voids and cracks, the latter took place at grain boundaries under triaxially stressed state caused by buckling of the elongated grains.
(4) Mean diameters of dispersoids before and after heating at 1623K (0.986Tm, Tm: solidus) for 200hr were 13.1 and 21.2nm, and the drop of hardness was minimal 6 or 7%, which shows strong stability of them at such a high temperature.抄録全体を表示PDF形式でダウンロード (6244K) -
野田 俊治, 飯久保 知人, 磯部 晋1990 年 61 巻 2 号 p. 102-109
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーThe fracture toughness of TiAl intermetallic compound was investigated. The ingots of TiAl with stoichiometric 36.0wt% Al and non-stoichiometric 33.8wt% Al are melted and cast by an Ar-plasma skull casting furnane. The fracture toughness test was made on these TiAl as-cast ingots by using compact tension specimens. The 36wt% Al ingot with small amount of Ti3Al in TiAl and rather smooth grain boundary showed low fracture toughness value of 20MPa √m which was similar to ceramics. The 33.8wt% Al ingot with fine TiAl/Ti3Al lamellar structure and zigzag grain boundary showed higher strength and ductility than 36wt% Al ingot reached 46MPa √m fracture toughness value near to Ni base superalloy.抄録全体を表示PDF形式でダウンロード (8281K) -
鈴木 昭弘, 飯久保 知人1990 年 61 巻 2 号 p. 110-116
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーTi-(3∼16)%V-(3∼11)%Cr-3Al beta type alloys are used to investigate the effects of beta stabilized elements on cold workability and aging characteristics. Compressive test and cold rolling test are examined to estimate cold workability of solution treated specimens. Hardness is measured and microstructures are observed to estimate aging characteristics of solution treated and cold rolled specimens.
Hardness of solution condition depends mainly on chromium level. Vanadium equivalent is used for an index of beta phase stability. It is useful to distinguish the phase boundary of martensite and beta phase after solution treatment. It is effective for the level of cold workability, too. Specimens that have high vanadium equivalent show good cold-workability. With the increase of vanadium equivalent, age hardening rate is accelated and the increment of hardness by aging is decreased.抄録全体を表示PDF形式でダウンロード (5614K) -
太田 芳雄, 中川 幸也1990 年 61 巻 2 号 p. 117-123
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーGreater jet engine power and fuel economy have been achieved by increased turbine firing temperature and adaption of efficient cooling systems. The means for attaining reduced cooling flow while increasing life and reliability include refinement of new high temperature materials and fabrication process. This paper provides examples from current and future engines. Ti and Ti alloys, and Ni-Cr-Fe alloys have been the primary materials in compressor components. Higher temperature capability will be a key requirement in next engines where new Ti alloys, aluminide intermetallics, and surface coating technologies will likely be incorporated. Althogh the superalloys, Ni-and to some extent Co-base, continue to be major materials in hot zone, it is apparent that their maximum use temperature is rapidly being approached. The use of new materials for potential payoffs is extensively studied to increase the temperature capability and/or to reduce densities. These include ceramics, intermetallics and composites. Any prediction of course, depends on the R&D efforts that are sustained over a period of 5 to 15 years in order for the materials and design engineers to be able to bring these materials to a point of realiness.抄録全体を表示PDF形式でダウンロード (4646K) -
三田 裕弘1990 年 61 巻 2 号 p. 124-135
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーCeramic (codierite) supports are now used for automotive catalyst. In recent years metal supports are getting to attract strong attention. With 1/3 thinner wall thickness (50micron), 45% more geometrical surface, 20% more open frontal area compared to ceramic ones, we have achieved less back pressure, higher emission performance, and compactness.
Here we describe mainly from the standpoints of material, support structure and fixing technology.抄録全体を表示PDF形式でダウンロード (12224K) -
石川 達雄, 中倉 光康, 鈴木 義人, 森部 一夫1990 年 61 巻 2 号 p. 136-141
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーDaido Steel has performed fine grain control technology on the primary α of Ti-6Al-4V alloy, using GFM forging machine (NFP). As for the effect of microstructure on the mechanical properties of Ti-6Al-4V alloy, fatigue strength has been effected not only by the primary α grain size but also by the α volume fraction. As for the relation between fatigue limit ratio (fatigue limit/tensile strength) and α volume fraction, as the α volume fraction decreased, fatigue limit ratio improved. However, the α volume fraction was astringent when it became approximately 35%. As for the effect of α grain size on the fatigue limit, we recognized that the fatigue limit and 1/√d (d=α grain size) are linear. When the α grain size became finer that 10μm with approximately 35% α volume fraction, the fatigue limit was more than 45kgf/mm2.抄録全体を表示PDF形式でダウンロード (3419K) -
野田 孝昭, 和泉 喜久磨, 中山 傑, 中坪 修一, 高橋 誠, 有光 功1990 年 61 巻 2 号 p. 142-148
発行日: 1990/05/25
公開日: 2009/05/25
ジャーナル フリーThe DC (Direct Current) arc furnace with single graphite electrode at Hoshizaki Plant of Daido Steel has been operating since it was put into operation in August 1989.
In the course of test operation of the furnace, it works good in general and the main subjects of development were to establish the technology of electrical magnetic field which caused the arc deflection and to learn the operation software.
The characteristics and behaviours of direct current through test operation has proved the numerous advantages of the DC arc furnace in comparison with conventional AC (Alternate Current) arc furnaces.
The major benefits of the DC arc furnace are the savings in electric consumption and electrode consumption, easy furnace operation, and the reduction in electrical perturbation.
The present paper outlines the feature of the equipment and the results of test operation of the DC arc furnace.抄録全体を表示PDF形式でダウンロード (4092K)
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