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後続誌
63 巻, 2 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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研究論文
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高野 憲三, 名取 義勝1991 年 63 巻 2 号 p. 131-135
発行日: 1991/02/25
公開日: 2011/07/08
ジャーナル フリーProcess of the deteriorating mechanism of the strength has been investigated, by the aid of scanning electron microscopic photographs. Fissured structure of hardened Na-silicate coatings on sand grains were observed.
According to this results, deteriorations of strength of silicate moulds hardened by CO2 can be explained with binder links fissured by the formation of voids and by the crystallization of carbonates arising during the passage of vapors.抄録全体を表示PDF形式でダウンロード (856K) -
崔 沓川, 柿原 真一, 大城 桂作1991 年 63 巻 2 号 p. 136-142
発行日: 1991/02/25
公開日: 2011/07/08
ジャーナル フリーSpheroidal graphite cast irons containing 0.06 % Mn and 0.45 % Mn were quenched during austempering at 523 K to 698 K and the variations of microstructures and carbon content of retained austenite were examined to clarify the influence of manganese on the transformation process. Bainitic ferrite nucleated at grain boudary of austenite and grew in the form of plates in each grain, while the bainite transformation was inclined to proceed from graphite nodule to eutectic cellular boudary because of normal segregation of manganese. The coaseness of the bainitic ferrite was evaluated as the spacing and width of plate-like bainitic ferrite. They decreased with decreasing transformation temperature, while manganese little affected the coaseness. Manganese retarded the transformation, and so called γ-pools remained at cellular boundary of 0.45 % Mn iron where manganese increased to more than double the alloy content during solidification. The bainite transformation proceeded more homogeneously at a higher rate, and the enrichment of carbon into austenite and also the complete decomposition of austenite occured faster in 0.06 % Mn iron.抄録全体を表示PDF形式でダウンロード (849K) -
堀江 皓, 楊 忠亮, 小綿 利憲, 平塚 貞人, 袁 錫爵, 勝負沢 善行1991 年 63 巻 2 号 p. 143-148
発行日: 1991/02/25
公開日: 2011/07/08
ジャーナル フリーRare earth elements, such as cerium (Ce), lanthanum (La), neodymium (Nd) and yttrium (Y) were added into flake graphite cast iron melt on different sulfur levels in order to examine the effects of elements on chilling tendency and tensile strength and, the behaviors of the elements and sulfur. The results obtained were as follows :
(1) Addition of Ce, La, Nd or Y was very effective for the improvement of graphite shape, the refinement of eutectic cells, the reduction of chilling tendency and the enhancement of mechanical properties in flake graphite cast iron.
(2) The effect of rare earth elements on chilling tendency and so on was strongly dependent upon sulfur content in melt. With higher sulfur content, the degree of improvement of chilling tendency, microstructure and mechanical properties becomes larger.
(3) It is considerable that rare earth elements react with sulfur in melt, and that the sulfide formed helps the nucleation of flake graphite, so leads remarkable graphitization.抄録全体を表示PDF形式でダウンロード (817K) -
金 基永, 鈴木 康行, 鈴木 俊夫, 梅田 高照1991 年 63 巻 2 号 p. 149-154
発行日: 1991/02/25
公開日: 2011/07/08
ジャーナル フリーDisplacements of the casting and mold during solidification and cooling were measured for Al-Si binary alloy castings with various silicon contents, which showed various solidification modes and solidification contractions with silicon content.
The maximum contraction time of the mold cavity showed good agreement with the maximum heat transfer coefficient time. This was attributed to heat flow acceleration because of good contact due to the mold bending.
Deformation of the casting itself after air gap formation was not proportional to silicon content. It was large in eutectic alloy castings. The ratio of the mold cavity contraction at air gap formation to the total deformation of the casting was in the range of 20-50 %. It depended on silicon content and on initial mold temperature. However it was about 10 % for eutectic alloy castings. Therefore the effect of the mold deformation on the deformation of the casting was smallest in eutectic alloy castings.
It was thought that the deformation of the casting did not depend directly on the solidification contraction of the alloy itself, but was greatly influenced by feeding of molten metal under certain casting conditions.抄録全体を表示PDF形式でダウンロード (696K) -
加藤 清隆, 野崎 佳彦1991 年 63 巻 2 号 p. 155-160
発行日: 1991/02/25
公開日: 2011/07/08
ジャーナル フリーInjection molding process was applied to manufacturing ceramic core for precision castings. The properties of this ceramic core was studied, too.
The binder of injection molding consists of wax and methacrylic resin. The composition of powder of ceramic core is 80 wt %-fuesd silica and 20 wt %-cristobalite. The binder was mixed with this powder at the content of 16.7 wt % binder. As a result of molding dewaxing and burning, the core had no crack and little deformation.
The ceramic core by injection molding had high density and high deflective strength compared with that by press molding. But, the formar had higher shrinkage and lower apparent porosity than the latter.
With the addition of 4 wt % alumina or zircon powder to this core, it brought lower shrinkage, higher apparent porosity and higher dissolusion in alkali. In particular, the fine alumina powder had large effect.抄録全体を表示PDF形式でダウンロード (622K)
技術報告
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松川 安次, 中島 昌身, 曽我 正清, 木戸 正行, 森 正博1991 年 63 巻 2 号 p. 161-165
発行日: 1991/02/25
公開日: 2015/01/22
ジャーナル フリーPDF形式でダウンロード (2455K) -
土井 基邦, 泉谷 信廣1991 年 63 巻 2 号 p. 166-171
発行日: 1991/02/25
公開日: 2015/01/22
ジャーナル フリーPDF形式でダウンロード (3382K)
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