巻号一覧
後続誌
49 巻, 3 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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喜多 清, 山本 和平, 中村 敬和1977 年 49 巻 3 号 p. 137-143
発行日: 1977/03/25
公開日: 2012/07/10
ジャーナル フリーThe dendrite-like structure in the annealed structure of steel castings, which is considered as an annealed structure and has no effect on the mechanical properties stated in the standards of the tensile test, has not been studied enough to be understood in detail. The authors have been finding such structures in parts of Y-block specimen. The present study to obtain a sufficiently homogeneous annealed structure and to understand the process of formation of such structures was carried out through the discussion on the changes in the annealing conditions by observation of the microstructure and analysis by the electron probe microanalyzer.
The dendrite-like structure in the annealed structure can be improved by elevating the annealing temperature or by repetition of annealing, which changes the structure into a considerably homogeneous one. The dendrite-like structure is formed due to insufficient diffusion of solute elements during solidification and unhomogeneous deposition of carbon, once diffused in austenite, with segregated elements during slow cooling after annealing. Such dendrite-like structure is an unhomogeneously annealed structure which resulted from heating and cooling under imperfectly thermal condition.抄録全体を表示PDF形式でダウンロード (1605K) -
高柳 猛1977 年 49 巻 3 号 p. 144-149
発行日: 1977/03/25
公開日: 2012/07/10
ジャーナル フリーColloidal silica which is widely using as a binder to make ceramic shell mold, goes through the stages of drying (after slurry coating on wax pattern) and heating (for dewax and mold firing) during mold making. Then, water evaporation from colloidal silica and consequent aggregation of dispersed silica particles were studied by drying and heating below 500°C.
Below 500°C, water as disperse medium is evaporated. From the total grammetric analysis curve gained at the heating speed of 2.5°C/min, colloidal silica lost 65-66% of water at 100°C though the water content in the sample was about 70%. The water which evaporated is considered to be the liberated water. The residual moisture was evaporated by keeping the sample at 100°C for several hours. Amorphous silica was produced when colloidal silica was thoroughly dehydrated. By the following process, solid amorphous silica is considered to be produced from colloidal silica. In the original colloid, it is considered that the silica particles are dispersed in water with many silanol bonds (Si-OH). When water evaporates from colloidal silica, such particles colloide in succession with each other. And as the following bridging reaction occurs, silica particles aggregate together into amorphous silica.
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福迫 達一, 大中 逸雄, 山内 勇, 松井 利弘1977 年 49 巻 3 号 p. 150-156
発行日: 1977/03/25
公開日: 2012/07/10
ジャーナル フリーA laboratory equipment for the production of pipes was proposed and developed. With this method, the molten metal was sucked into a metallic mold by a vacuum pump and then poured out. Experiments were made on pure Al, Al-2%Cu and Al-5%Cu alloys. Smooth surface pipes were produced and their thickness was controlled by the holding time. Their mechanical properties were higher than those of conventional metallic mold castings. Transient variation of metal height and suction rate in mold with time were calculated using simple assumptions. Agreement between theory and experiment was obtained qualitatively.抄録全体を表示PDF形式でダウンロード (811K) -
伊藤 普, 田口 幸二, 竹下 武志1977 年 49 巻 3 号 p. 157-161
発行日: 1977/03/25
公開日: 2012/07/10
ジャーナル フリーCast bonding of steel pipes coated with Ni-P alloy plating by ductile cast iron was studied. Bonding conditions were examined by tensile strength tests, hydraulic pressure test, observations by microscope and EPMA. Bonding condition was good judging from the results of strength and hydraulic pressure tests, and the structure of the bonding part was good judging from observations by microscope and EPMA. Results of line analysis on Ni and P by EPMA showed that Ni and P were sufficiently diffused in the cast iron and the steel pipe, so there was no segregation of steadite and it showed that there was good diffusion bonding between the steel pipe and the cast iron. This process was applied to fin tubes of ships and it is planned to be used in other parts as well.抄録全体を表示PDF形式でダウンロード (712K) -
佐藤 敬, 高橋 利次, 松本 昇1977 年 49 巻 3 号 p. 162-167
発行日: 1977/03/25
公開日: 2012/07/10
ジャーナル フリーReagent grade calcined calcium oxide powder crushed to pass a 5 mesh sieve was used as a starting material and a solution of 4g unhydrated calcium chloride per 100cc of ethanol was added to the powder as a binder. The mixture was hand-rammed to the inside of an outer crucible and fired in an electric resistance furnace at 900°C for 1hr. Several melting experiments using a high frequency induction furnace were carried out to test the usability of the lime crucible prepared under these conditions. The crucible was stable enough against pure chromium melt in argon atmosphere. The crucible was however attacked when it was brought into contact with super-heated molten titanium, but some possibilities of using the mixture as a mold material for titanium casting were indicated. Cast iron melted in the lime crucible together with lime-fluospar flux in the open atmosphere could be desulfurized below 10ppm. No failure occured after three times of vacuum melting each 5kg charge of electrolytic iron in the same crucible.抄録全体を表示PDF形式でダウンロード (780K) -
市川 理衛, 冨山 直樹1977 年 49 巻 3 号 p. 168-173
発行日: 1977/03/25
公開日: 2012/07/10
ジャーナル フリーThe effect of fluid flow and convection on solidified structures of aluminum, Al-0.01%Ti-0.002%B and Al-6.0%Cu alloys were studied by pouring into a mold set with a chill-block at the upper top and tilting it 90°, 60°, 30° and horizontally. Columnar grains inclined in the upstream direction to the solid-liquid interface. Grain refining effect was enhanced by convection on the solidification of Al-Ti-B alloy. The advancement of the solid-liquid interface depended on cooling by the chill-block and on convection of melt in the mold. Fine primary grains or dendrite segments ahead of the advancing interface sinked to the bottom in aluminum and Al-Ti-B alloy, but the was not observed in Al-Cu alloy.抄録全体を表示PDF形式でダウンロード (921K)
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