巻号一覧
後続誌
53 巻, 7 号
選択された号の論文の6件中1～6を表示しています
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研究論文
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大野 篤美, 南 和一郎, 金谷 章宏1981 年 53 巻 7 号 p. 347-353
発行日: 1981/07/25
公開日: 2012/02/16
ジャーナル フリーCommercial pure aluminum was poured into molds having different cooling powers. Temperatures were continuously measured in the mold and molten metal. As the average heat flux toward the mold from the molten metal increase, the equiaxed zone initially increases and decreases suddenly and rapidly. Two types of heat transfer behavior at the mold-metal interface are found. When the rapid cooling mold is used, the heat transfer coefficient initially rises rapidly and falls quickly down to a stable state, and soon a stable solid shell is formed. On the other hand, in the molten metal to be solidified into the macrostructure having the equiaxed zone, the heat transfer coefficient rises with fluctuation in the early stage of solidification and falls. The fact shows delay in forming the stable shell. This is caused by separation of crystals from the mold wall in the initial stage of solidification.抄録全体を表示PDF形式でダウンロード (875K) -
佐藤 兼弘, 目黒 勝, 高橋 宥夫1981 年 53 巻 7 号 p. 354-358
発行日: 1981/07/25
公開日: 2012/02/16
ジャーナル フリーA process for eliminating excess titanium in molten cast iron economically and easily is proposed in which excess titanium can be eliminated as a titanium nitride at 1,330°C or below. The nitrogen source is such a nitride as lime nitrogen. The slagging agent which traps the titanium nitride is soda ash. About 50% of the total titanium is eliminated under optimum conditions.抄録全体を表示PDF形式でダウンロード (607K) -
堺 邦益, 喜多 清1981 年 53 巻 7 号 p. 359-362
発行日: 1981/07/25
公開日: 2012/02/16
ジャーナル フリーThe fracture process of binary carbon steel castings was studied in relation to casting defects by optical and scanning electron microscopies. The first step in the fissuring process is formation and coalescence of microvoids around pearlite nodules and inclusions. Casting defects influences the fracture behavior of cast steel in a complex manner. Although micro-defects such as shrinkage considerably lower the elongation, they have little effect on tensile and yield strength. The formation of small dimples on the fracture surface in the vicinity of the defects is probably not so susceptible to these casting defects.抄録全体を表示PDF形式でダウンロード (709K) -
岸武 勝彦, 大和田野 利郎, 宮本 浩二1981 年 53 巻 7 号 p. 363-368
発行日: 1981/07/25
公開日: 2012/02/16
ジャーナル フリーThe temperature of eutectic growth front was measured in unidirectionally solidifying Fe-C-Cr eutectic cast irons. In cast irons containing Cr 0.3% and 0.5%, flake graphite eutectic grows at low growth rates and ledeburite eutectic grows at the rate about 1μm/sec or more. Flake graphite eutectic and ledeburite eutectic simultaneously grow at the rate where the transition from flake graphite eutectic to ledeburite eutectic solidification occurs. Undercooled graphite eutectic often appears in 0.3% Cr cast iron instead of ledeburite eutectic at high growth rates. Graphite eutectic appears neither in 1% nor 2% Cr cast iron. Ledeburite eutectic grows at higher temperature than the undercooled graphite eutectic. The temperature depression of ledeburite eutectic is linear to the square root of the growth rate in the range of high growth rate at which the solid-liquid interface of the eutectic is of well-developed cellular structure. The equilibrium ledeburite eutectic temperature rises and the equilibrium austenite-graphite temperature falls with an increase of Cr content. The transition from flake graphite eutectic to ledeburite eutectic solidification is well explained in terms of the relationship between the growth temperature and the growth rate. Chromium has such effects as facilitating nucleation of ledeburite eutectic and raising the ledeburite eutectic temperature on the transition.抄録全体を表示PDF形式でダウンロード (818K) -
松原 安宏, 本田 義興, 西 希一, 松田 公扶1981 年 53 巻 7 号 p. 369-375
発行日: 1981/07/25
公開日: 2012/02/16
ジャーナル フリーHot rolling was carried out of high chromium cast irons containing chromium 15 and 30% in which the eutectic ratio was controlled to be 65 to 100% for the purpose of breaking down the eutectic carbides and dispersing them. The high chromium cast iron is plastically workable under some appropriate rolling conditions. The hot rolling workability is improved by elevating the rolling temperature. A critical temperature TC at which the workability abruptly increases is also found. As the rolling reduction is increased and the carbon and chromium contents are increased, TC rises and the workability becomes poor. The eutectic carbides having rod or plate shape are deformed, broken down and dispersed uniformly in the matrix by hot rolling.抄録全体を表示PDF形式でダウンロード (939K) -
大中 逸雄, 長坂 悦敬, 福迫 達一, 吉岡 二郎1981 年 53 巻 7 号 p. 376-382
発行日: 1981/07/25
公開日: 2012/02/16
ジャーナル フリーA three-dimensional solidification analysis of castings and its input data generation software are presented. The geometry to be analyzed is divided into elements such as pentahedrons and hexahedrons which have a nodal point in themselves. The heat balance equations for the elements are solved numerically. The input data for the analysis are generated interactively by the use of computer graphics. A method of predicting the shrinkage defect by a gradient of the permeability is proposed and some numerical examples are demonstrated. The calculated values agree with the experimental ones in most cases. A more precise prediction of the defect may require the consideration of flow phenomena and the heat transfer during pouring. The proposed method can be developed into such analyses.抄録全体を表示PDF形式でダウンロード (684K)
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