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56 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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藤井 則久, 藤井 満, 森本 庄吾, 岡田 千里1984 年 56 巻 7 号 p. 387-392
発行日: 1984/07/25
公開日: 2011/11/26
ジャーナル フリーMetal mold, ceramic mold and N process sand mold gravity castings and metal mold squeeze castings of AC4C aluminum alloy were investigated. Microstructures particularly eutectic silicon particles and mechanical properities of the castings were interrelated. Mechanical properties of aluminum alloy castings particularly elongation, impact value and fatigue strength are considerably affected by eutectic silicon particle size. Initiation and propergation in the castings can be minimized by refining eutectic silicon. Squeeze casting is an effective means of obtaining desirable microstructures.抄録全体を表示PDF形式でダウンロード (725K) -
久保 公雄, 福迫 達一1984 年 56 巻 7 号 p. 393-401
発行日: 1984/07/25
公開日: 2011/11/26
ジャーナル フリーA new model to express heat and moisture transfer in green sand molds is proposed. Basic equations for sand and gas temperatures, vapor and air pressures, and moisture content are derived. Temperature heating curves calculated by using a finite difference method well coincide with the measured values. The calculated moisture content and gas pressure also well coincide with the measured ones. The calculation shows that moisture vaporizes not only at the interface of dry sand and vapor transport zone but also at the condensation zone. The likelihood of blows is greatly increased with the diminishing diameter of sand because of the poor transfer of vapor due to reduced permeability.抄録全体を表示PDF形式でダウンロード (761K) -
三輪 謙治, 安藤 芳康, 大橋 照男1984 年 56 巻 7 号 p. 402-407
発行日: 1984/07/25
公開日: 2011/11/26
ジャーナル フリーWhen Al-Al2Cu eutectic alloys are stirred in the liquid-solid state and are solidified, two unique structures are found. One is coexistance of free Al2Cu with primary α and eutectic particles in hypoeutectic alloys and coexistance of free α with primary Al2Cu and eutectic particles in hypereutectic alloys. Another is crystallization of eutectic particles in the form of rectangular prism. This shape of the eutectic particle is caused by a primary or free Al2Cu crystal. The size of eutectic particles decreases by increasing the stirring rate. It is suggested that a possible origin of the free Al2Cu phase is in the morphology of the cellular solid-liquid interface of an eutectic particle and that the leading Al2Cu phase are rejected out of the cellular interface by stirring.抄録全体を表示PDF形式でダウンロード (887K) -
鹿毛 秀彦, 田中 雄一1984 年 56 巻 7 号 p. 408-414
発行日: 1984/07/25
公開日: 2011/11/26
ジャーナル フリーMechanical properties and microstructures of various iron castings were correlated by means of ultrasonic measurement and image analyzing. Ultrasonic velocity decreases as the graphite transforms from nodular to flake. A velocity approximately 5,300m/s differentiates high strength cast irons such as spheroiolal graphite iron and CV graphite iron having nodular graphite from gray iron or typical CV graphite iron. A linear relationship lies between the mean shape factor of graphite and ultrasonic velocity at the velocity 5,300m/s or more or at the shape factor of graphite 35% or more. If the amount of pearlite in the matrix is constant, closed relations are found between the mechanical properties and the velocity of ultrasonic energy. The amount of pearlite in the matrix can be assessed by hardness testing of castings having the same graphite shape. Ultrasonic velocity measurement in combination with hardness testing is the most satisfactory method for indirectly assessing the tensile properties of high strength irons having different graphite and matrix structures. The information derived from ultrasonic testing can be used for quality and process control as well as for quality assurance of finished products.抄録全体を表示PDF形式でダウンロード (763K) -
青山 正治, 横井 時秀, 小林 俊郎1984 年 56 巻 7 号 p. 415-420
発行日: 1984/07/25
公開日: 2011/11/26
ジャーナル フリーThe effect of prior heat treatment history on the toughness of ferritic spheroidal graphite cast iron was studied. Test castings were ferritized by two-step annealing and were heat treated to form pearlitic, bainitic and martensitic matrix structures. They were ferritized in the temperature range from 750°C to 650°C for 20h. Irons ferritized from pearlite and bainite matrices have greater energy absorption values at room temperature with the rise of ferritizing temperature, whereas the one ferritized from martensite matrix is independent of ferritizing temperature. Fine prior structure leads to fine ferritic grain size. Transition temperature rises with the rise of ferritizing temperature particularly in the martensitic structure. Transition temperature in the castings ferritized from martensite is lowered by refining of the ferrite grain size and precipitation of secondary graphite particles.抄録全体を表示PDF形式でダウンロード (684K) -
牧村 実, 堺 邦益, 西山 幸夫, 田中 正則1984 年 56 巻 7 号 p. 421-425
発行日: 1984/07/25
公開日: 2011/11/26
ジャーナル フリーThis is the third progressive work which follows a proposal of finite element three-dimensional thermal analysis and its trial to spheroidal graphite cast iron test castings to predict microstructures and mechanical properties from the cooling rate thermally analyzed. Such factors of microstructures as average graphite diameter and area ratio of pearlite phase to matrix and such mechanical properties as Vickers and Rockwell hardness numbers and tensile properties were evaluated analytically and experimentally for practical crankshafts for industrial engines having chemical compositions nearly equal to those in the preceding works. The evaluated values well agree with those experimentally obtained. Microstructures and mechanical properties of practical spheroidal graphite iron castings are predictable by using the three-dimensional thermal analysis.抄録全体を表示PDF形式でダウンロード (585K)
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