巻号一覧
後続誌
65 巻, 6 号
選択された号の論文の9件中1～9を表示しています
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研究論文
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佐藤 勉, 久保田 耕平, 二宮 隆二1993 年 65 巻 6 号 p. 457-461
発行日: 1993/06/25
公開日: 2011/06/22
ジャーナル フリーTwo high strength Zn alloys for molds, Z 1610 (Zn-16 Al-10 Cu-0.02 Mg) and Z 2520(Zn-25 Al-20 Cu-0.02 Mg), are newly developed. The fatigue test and the wear test of these new alloys are carried out to compare with existing alloys, ZAS (Zn-4 Al-3 Cu-0.05 Mg), ZA 12 (Zn-12 Al-1.5 Cu-0.02 Mg) and ZA 27 (Zn-27 Al-2.5 Cu-0.02 Mg). The results are as follows. (1) The low cycle fatigue strengths of Z 1610, Z 2520, ZA 12 and ZA 27 are much higher than ZAS. For example the fatigue strength at 1 × 105 cycle of Z 1610 is 142 MPa while that of ZAS is 123 MPa. (2) The high cycle fatigue strengths of all tested alloys are much the same. That at 1 × 107 cycle is about 100 MPa. (3) Z 1610 and Z 2520 show the better wear property than ZAS, ZA 12 and ZA 27. Z 1610 and Z 2520 are excellent materials for molds.抄録全体を表示PDF形式でダウンロード (678K) -
安江 和夫, 斉 世長, 西尾 敏幸, 山田 康雄, 小畑 良洋1993 年 65 巻 6 号 p. 462-467
発行日: 1993/06/25
公開日: 2011/06/22
ジャーナル フリーThe consolidation and sintering behavior and the microscopic structure during or after sintering were investigated for the samples A (Fe-4.29 % C) and B (Fe-3.88 % C-1.86 % Si) of cast iron powder which were atomized by the water. A summary of results is shown below. Sample B with silicon could not obtain a sufficient density compared to sample A because graphite precipitates at grain boundaries prior to sintering reaction. The similar effect was also recognized on the specimens which were sintered using a mixed powder of a metal powder of graphitization element and sample A. The structure after sintering on both the samples was fine pearlite, and the graphite was too fine to be observed by optical microscope. However hardness of the samples were very low (HRB = 20) compared to a practical cast iron. The decomposition rate of carbides in as-received powder is considerably high. Carbides were completely decomposed at 3.6 ks after heating even the sample A without silicon.抄録全体を表示PDF形式でダウンロード (649K) -
岸武 勝彦, 恵良 秀則, 大坪 文隆, 李 平, 若山 登1993 年 65 巻 6 号 p. 468-473
発行日: 1993/06/25
公開日: 2011/06/22
ジャーナル フリーHigh-carbon Cr-Mo iron alloys containing boron have been rapidly solidified into ribbons by means of a single roller method. The iron alloys of almost eutectic composition form an amorphous phase throughout the ribbon. The amorphous phase decomposes or crystallizes to exhibit ultra-fine equiaxed grains of ferrite and borocarbides during tempering. An extremely high hardness over 1500 DPN has been obtained just after the crystallization of the amorphous phase. The high hardness is attributed to the ultra-fine grain structure, i. e., nanocrystals of ferrite and borocarbides.抄録全体を表示PDF形式でダウンロード (901K) -
洪 鍾徽, 洪 英煥, 高 世炫1993 年 65 巻 6 号 p. 474-479
発行日: 1993/06/25
公開日: 2011/06/22
ジャーナル フリーThe mechanical properties of ductile cast irons depend primarily upon their matrix structure. For the improvement of matrix structure, many researches on austempering process and alloy additions have been studied. But austempering process is too complex and make the cost higher. Therefore, the effect of alloying elements such as Ni, Mo and Cu on the microstructures of as-cast ductile cast iron were investigated in this study for 15 different compositions. The composition range of the alloying elements were Ni(0.0 to 4.0 mass %), Mo(0.0 to 0.6 mass %) and Cu(0.0 to 1.2 mass %). Prediction models for impact value and hardness were developed by regression analysis method (Response Surface Analysis). The result was well agreed with experimental value. While Ni and Cu improved hardness and reduced impact value, Mo increased impact value as well as hardness. The relationship between impact value and hardness were in directly inverse proportion.抄録全体を表示PDF形式でダウンロード (786K) -
桑野 正司, 大城 桂作, 沢本 章1993 年 65 巻 6 号 p. 480-484
発行日: 1993/06/25
公開日: 2011/06/22
ジャーナル フリーFe-Cr-C alloys containing 1∼25 mass % chromium and 20 vol % eutectic were destabilized at 1123 K for 60 to 18 ks in a salt bath immediately after their solidification and the precipitation processes of secondary carbides were investigated by using SEM and TEM. In 1 and 5 mass % chromium irons, the secondary carbides develop from the surface of eutectic carbides toward the center of dendrite. In 10, 15 and 25 mass % irons, fibroid carbides precipitate from the vicinity of eutectic carbides and they grow up to the columnar type carbides. Electron diffraction analysis revealed that M3C precipitated in 1 mass % chromium iron, M7C3 and M3C in 5 mass % chromium iron, M23C6, M7C3 and M3C in 10 mass % chromium iron and M23C6, M7C3 in 15 mass % chromium and 25 mass % chromium irons. Chromium retards the precipitation of secondary carbides and the precipitation start time (ts) becomes larger with an increase in Cr/C, the ratio of chromium content to carbon content of alloy, as expressed by an equation : ts ≒ 5.94 (Cr/C)1.985.抄録全体を表示PDF形式でダウンロード (762K) -
高橋 利夫, 栗花 信介, 多田 周二, 阿部 利彦1993 年 65 巻 6 号 p. 485-490
発行日: 1993/06/25
公開日: 2011/06/22
ジャーナル フリーThe volume of retained austenite and residual stress of ferrite on mechanically worked surface of ADI (Austempered Ductile Iron) were measured by X-ray diffraction method to investigate the relationships between them. In polishing, the volume of retained austenite decreases on the surface where large compressive residual stress is observed. The decrease of retained austenite by stress-induced martensitic transformation is larger in grinding than in polishing. Low-carbon austenite (< 1.3 % C) is retained at the early stage of isothermal transformation and it easily transforms into martensite by polishing, while high-carbon austenite is stable. It is necessary to austemper until only high-carbon austenite is retained in order to obtain ADI with good mechanical properties.抄録全体を表示PDF形式でダウンロード (659K)
解説
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佐々木 敏美, 星野 薫, 中村 幸吉, 炭本 治喜1993 年 65 巻 6 号 p. 491-498
発行日: 1993/06/25
公開日: 2015/01/21
ジャーナル フリーPDF形式でダウンロード (3803K)
技術報告
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佐野 弘明1993 年 65 巻 6 号 p. 499-505
発行日: 1993/06/25
公開日: 2015/01/21
ジャーナル フリーPDF形式でダウンロード (3148K) -
岡崎 健, 徳吉 稔, 楠木 弘明1993 年 65 巻 6 号 p. 506-512
発行日: 1993/06/25
公開日: 2015/01/21
ジャーナル フリーPDF形式でダウンロード (3533K)
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