巻号一覧
後続誌
50 巻, 9 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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宇佐美 正, 井川 克也, 芹田 陽1978 年 50 巻 9 号 p. 531-536
発行日: 1978/09/25
公開日: 2012/06/02
ジャーナル フリーHypo- and hyper-eutectic white cast irons containing 15%Cr or 15%Cr and 3%Ni were heated at 425°C for 8 hr and either 750°C or 930°C for 3hr, and air-cooled. These specimens were tested for sand erosion properties in a mixture of sand and either water or seawater. It was observed that in spite of the increase in hardness by heat treatment at 450°C and 750°C, sand erosion resistance decreased in both cases especially in hot test mixtures. The electron scanning microscopic observation of the worn surfaces of these heat-treated specimens suggested that corrosion of the boundary between matrix and carbide was more remarkable than the as-cast or heat-treated (at 930°C) specimens. The corrosion was accompanied by mechanical fracture of carbide and resulted in increased sand erosion. It was concluded that heat treatment for improving the sand erosion resistance of the white cast iron should be such that it increases hardness but does not lower the corrosion resistance of irons.抄録全体を表示PDF形式でダウンロード (860K) -
藤本 留吉1978 年 50 巻 9 号 p. 537-542
発行日: 1978/09/25
公開日: 2012/06/02
ジャーナル フリーA theoretical and practical study was conducted on what effect stoma had on the property of casting mold as well as limited remaining moisture on a slag-sodium silicate process, and the following equation was obtained. S–BebP, where S is strength of a group of sand, b is proportional constant, P is stoma of mold.抄録全体を表示PDF形式でダウンロード (717K) -
竹内 宏昌, 池田 実, 梅田 高照, 木村 康夫, 椙山 正孝1978 年 50 巻 9 号 p. 543-548
発行日: 1978/09/25
公開日: 2012/06/02
ジャーナル フリーThe solidification process and cast structure of pure aluminum, its alloys and copper alloys which have been centrifugally cast under 2−40G, were investigated. The solidification time of centrifuged castings was measured and was found that it was less compared to that of static castings (for example, with superheat of 50°C, the solidification time of pure aluminum decreased from 248 to 134 sec.), because the heat resistance in the metal-mold interface of centrifuged castings decreased. In Al-4.5%Cu alloy, cast structure of centrifuged castings shows a transition from equiaxed to columnar grains. Normal segregation occurred in this alloy under 40G.抄録全体を表示PDF形式でダウンロード (732K) -
坂本 敏正, 吉川 克之, 中村 実人, 森 隆資, 高田 寿1978 年 50 巻 9 号 p. 549-554
発行日: 1978/09/25
公開日: 2012/06/02
ジャーナル フリーThe solidification process of Fe-C-(Si) alloy with lamellar graphite was studied by measuring the intergraphite spacing and observing the three-dimentional graphite structure. The relation between the intergraphite spacing λ(μ) and solidification rate V (cm/hr) is represented by the following equation. λ=45.9V−0.513. Graphites are continuous with some branchings and terminations. The crystallized pattern was observed on several graphite flakes which indicates that lamellar graphite grew with a faceted interface. The experimental results on the λ−V relation for the eutectic fit the partially cooperative eutectic growth model better than the cooperative one.抄録全体を表示PDF形式でダウンロード (725K) -
房村 信雄, 雄谷 重夫, 名古屋 俊士1978 年 50 巻 9 号 p. 555-559
発行日: 1978/09/25
公開日: 2012/06/02
ジャーナル フリーTransmision electron microscopy was carried out on metallic fume generated from molten copper-base alloys. Fume particles of zinc, cadmium and magnesium have their respective forms. The fume particles of zinc generated from molten pure zinc change in shape from grobular to needle, rectangular and star-like in accordance with the change in temperature of the molten metal from 550°C to 900°C. If the fume generates at a constant rate, the distribution of size of fume particles shifts to a larger side in inverse proportion to the cooling rate. If the fume cools at a constant rate, the distribution of the size of fume particles becomes proportionate to the concentration of the fume generated from the molten metal.抄録全体を表示PDF形式でダウンロード (698K) -
野口 徹, 長岡 金吾1978 年 50 巻 9 号 p. 560-565
発行日: 1978/09/25
公開日: 2012/06/02
ジャーナル フリーLow temperature strength and stress–strain properties of gray cast irons were examined under tension and compression. The strain gauge method was employed on pearlitic and ferritic irons in the temperature range of +20°C to −196°C. Just as reported so far, the present experiments showed that the tensils strength, the proof strength and the elastic modulous increased by lowering the test temperature. Down to the temperature of −150°C, the tensile fracture strain decreased indistinctly in most irons expect for the ferritic one which showed the maximum value at −100°C. At −196°C, the fracture strain was reduced to as small as 0.4% in all irons. The stress-strain curves shifted to a higher stress level by decreasing the temperature, i.e., gradually down to −150°C and rapidly at −196°C. The shift of the curves were almost at the same rates both in tension and in compression. Such characteristics of gray cast irons at low temperatures were well expressed by factors a and b of the hyperbolic formula σ=bε/(a+ε) which approximates the stress-strain relation. Furthermore, SEM fractography revealed that the transition in the fracture appearance occured at about −150°C in ferritic irons, and in a ferritic iron there were some dimple patterns even at −196°C.抄録全体を表示PDF形式でダウンロード (760K)
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