巻号一覧
後続誌
58 巻, 10 号
選択された号の論文の7件中1～7を表示しています
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技術報告
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西崎 亘, 青山 勝彦, 岩崎 芳之1986 年 58 巻 10 号 p. 690-695
発行日: 1986/10/25
公開日: 2015/01/27
ジャーナル フリーPDF形式でダウンロード (2388K)
研究論文
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田中 雄一, 後藤 俊夫, 河合 徹, 井川 克也1986 年 58 巻 10 号 p. 696-701
発行日: 1986/10/25
公開日: 2011/10/25
ジャーナル フリーAustenite formation from spheroidite and pearlite in spheroidal graphite cast iron was studied using a rapid heating technique. Linear analysis and point counting on the quenched structure were carried out. The observed isothermal growth rate G of austenite is expressed as Gt=8.0×10−5cm/s at upper temperatures in the eutectoid transformaion region. Changes in G during transformation exceed two orders of magnitude. Activation energies for austenite growth are 68,500 and 260,000cal/mol respectively at upper and lower temperatures of eutectoid transformation. A suggested rate-determining mechanism includes diffusion of such alloying atoms as Cu at higher temperatures but not of carbon. The mechanism at lower temperatures includes the disintegration rate of cementite to ferrite. Assuming segregation of Cu atoms to the ferrite/austenite interface, the magnitude and remarkable time dependence of austenite growth rate are explained by a continuous change of carbon content in austenite. Austenite nucleates preferentially at the junction of carbides and ferrite grain boundaries of spheroidite and at pearlite colony intersections. Substantial grain refinement of two-phase mixed matrix structure is achieved for the cast iron with ferrite or pearlite colony further refined.抄録全体を表示PDF形式でダウンロード (730K) -
蘇 國璋, 大中 逸雄, 山内 勇, 福迫 達一1986 年 58 巻 10 号 p. 702-706
発行日: 1986/10/25
公開日: 2011/10/25
ジャーナル フリーThe surface level of molten metals in the riser placed on the top of a casting was measured. The riser was electrically heated for delaying solidification. The mold was made of CO2 sand, chamotte pipe, graphite pipe and CO2 sand backed steel pipe. The volumetric change increases in the order of : graphite pipe mold>steel pipe mold>chamotte pipe mold>CO2 mold. The volumetric change varies not only with mold strength but also with thermal expansion coefficient of the mold material. If the mold deformation is negligible, the volumetric change of spheroidal graphite iron castings may be calculated from the amount of austenite and graphite precipitated during eutectic solidification.抄録全体を表示PDF形式でダウンロード (612K) -
杉下 潤二1986 年 58 巻 10 号 p. 707-712
発行日: 1986/10/25
公開日: 2011/10/25
ジャーナル フリーSurface composite castings of Al-Cu-Mg alloy (2024) containing spheroidal graphite cast iron fibers were fabricated using centrifugal casting. If the external surface is composed at temperatures 700° to 750°C, G-number from 200 to 500 is required to achieve a preferable interface between the base alloy and dispersed layer. The cast iron fiber which has been combined for the purpose of improving wear resistance reacts with molten aluminum to form aluminide compounds FeAl or FeAl3. Although the aluminide compounds lower the bending strength of cast surface composites, they contribute to improve the wear resistance by controlling the adhesion between contacting surfaces.抄録全体を表示PDF形式でダウンロード (773K) -
今藤 雄治, 鈴木 俊夫, 宮田 保教, 梅村 晃由1986 年 58 巻 10 号 p. 713-718
発行日: 1986/10/25
公開日: 2011/10/25
ジャーナル フリーCu-5wt%Sn alloy was unidirectionally solidified at high temperature gradients up to 350°C/cm in a steady state manner. Dendrite tip radii estimated from the diameter of primary stems are in good agreement with those theoretically predicted basing on the interfacial stability. The dependence of primary and secondary dendrite arm spacings on growth rate and cooling rate was also examined. The dendrite spacing depends on the cooling rate nealy in the same manner in the non-steady state directional solidification.抄録全体を表示PDF形式でダウンロード (661K) -
毛利 勝一, 角谷 茂, 北沢 孝次1986 年 58 巻 10 号 p. 719-724
発行日: 1986/10/25
公開日: 2011/10/25
ジャーナル フリーA surface layer of high-Ni austenite ductile cast iron was rapidly remelted and solidified by LASER. The surface of the cast iron plate moving at constant speeds 0.8 and 1.0m/min was radiated by CO2 type LASER 1 and 2kW in power. The remelted and solidified layer radiated by 2kW LASER at a moving speed 1m/min has considerably fine structures and an average value of secondary dendrite arm spacing 2.8μm. The structure just beamed is ledeburite and is extremely hardened. The layer is harder than the graphitized matrix. A new surface treatment using rapid solidification is suggested from the fact.抄録全体を表示PDF形式でダウンロード (795K) -
池田 徹之, 西 成基, 粂内 弘幸, 辰田 好教1986 年 58 巻 10 号 p. 725-731
発行日: 1986/10/25
公開日: 2011/10/25
ジャーナル フリーAl-Pb-Cu alloys were cast into bars or plates in different two metal mold casting processes in order to suppress gravity segregation of Pb and to achieve homogeneous dispersion of Pb phase in the alloys. Solidified structures were analyzed by a video-pattern-analyzer. Plate castings 15 to 20mm in thickness of Al-Pb-1%Cu alloy containing Pb up to 5% in which Pb phase particles up to 10μm disperse are achieved through water cooled metal mold casting. The plates up to 5mm in thicness containing Pb as much as 8 to 10% cast in this process have dispersed Pb particles up to 5μm in diameter in the surface layer. Al-8%Pb-1%Cu alloy bars 40mm in diameter and 180mm in height in which gravity segregation of Pb is prevented can be cast by movable and water sprayed metal mold casting at casting temperature 920°C and mold moving speed 1.0mm/s. Pb phase particles 10μm in mean size are dispersed in the bars.抄録全体を表示PDF形式でダウンロード (838K)
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