巻号一覧
後続誌
55 巻, 11 号
選択された号の論文の5件中1～5を表示しています
- |<
- <
- 1
- >
- >|
研究論文
-
大和田野 利郎, 小林 俊雄, 村上 信義, 石橋 修次1983 年 55 巻 11 号 p. 657-662
発行日: 1983/11/25
公開日: 2011/12/13
ジャーナル フリーThe author made a study on the isothermal transformation of primary and eutectic metastable Fe2P phase into stable Fe3P phase in hypereutectic Fe-P alloy. Fe-13.6%P alloy melts were solidified in glass so that they contained rod-shaped priamry Fe2P particles embedded in matrices of α-iron and Fe3P in their microstructure. The number of primary Fe2P grains per unit area in the alloy increased as the undercooling of the primary Fe2P increased. Small specimens cut from those alloys were held at 900°C or 930°C for varied holding time and their microstructure were examined. The longer the holding time and the higher the holding temperature, the less fractions of Fe2P and the more fractions of surrounding Fe3P were observed. The holding time for the specimens to reach a definite level of transformation was inversely proportional to the number of Fe2P grains per unit area, which was in good accord with the diffusion-controlled transformation model. Using the diffusion data obtained from the transformation of primary Fe2P particles, an analogous model of the transformation of α-iron and Fe2P eutectic to α-iron and Fe3P eutectic during solidification was constructed. The model explained the relatively easy completion of transformation during solidification.抄録全体を表示PDF形式でダウンロード (764K) -
伊藤 光男, 千々岩 健児1983 年 55 巻 11 号 p. 663-668
発行日: 1983/11/25
公開日: 2011/12/13
ジャーナル フリーThe present paper deals with a measuring device built as a trial for continuous measurement of fume generated from various foundry equipments. Radioactive isotope 241Am is packed in the device and molecules of fume are electronically dissociated when they pass through the device, decreasing the electric current and changing the voltage. The amount of fume is determined from this voltage change. (1) A calibration curve between the amount of fume and the voltage was obtained for practical application of the device. We measured the amount of fume in various areas of a foundry with the device and confirmed good response. (2) The device was proved to withstand high temperature during measurements made in the pouring and melting areas. (3) With the measurements of concentration, wave-form and frequency of fume, this method enables the determination of the operation rate of equipments. Thus it can also be used as a production control tool.抄録全体を表示PDF形式でダウンロード (595K) -
倉部 兵次郎, 牧口 利貞, 村松 晃1983 年 55 巻 11 号 p. 669-675
発行日: 1983/11/25
公開日: 2011/12/13
ジャーナル フリーTwo problems arising from molding processes in foundry shops aroused our interest. One is the reduction of pollution and improvement of the working environment in the molding shop where noise, dust, fume and hot air are generated. The other is the reclamation of the used sand. For solving these problems an exothermic self-hardening and water-disintegrated alumina sand mold process was studied. (1) The alumina sand mold in which 4 parts of sodium aluminate solution and 0.8 parts of alumina powder are mixed as binder can be hardened by the exothermic reaction of the binder reaching 100°C and shows compressive strength of about 20 kg/cm2. (2) The hardening reaction starts immediately after mixing and continues to progress. The reaction can be retarded to give sufficiently long time for molding both by cooling the alumina sand and by partially forming sodium carbonate in sodium aluminate by mixing in CO2 gas atmosphere. (3) The mold can be easily disintegrated by spraying water at a pressure of 1 to 2 kg/cm2. (4) Alumina-iron oxide complex was not detected at the interface between the mold and molten cast iron. (5) There was no characteristic casting defects ascribable to the water-disintegrated mold.抄録全体を表示PDF形式でダウンロード (653K) -
岡田 明, 三宅 秀和, 尾崎 良平1983 年 55 巻 11 号 p. 676-682
発行日: 1983/11/25
公開日: 2011/12/13
ジャーナル フリーWhen hyper-eutectic white cast iron is molten at given temperatures between cementite (Fe3C) eutectic and graphite eutectic temperatures without graphitization in the iron and is held at the same temperatures, the amount of graphite eutectic formed increases by lowering the holding temperature, i.e. by increasing the degree of undercooling, and by increasing the holding time, just as in the case with hypo-eutectic or eutectic iron. The solidification of graphite eutectic in the melt of hypo-eutectic iron dose not start when the melt is held as long as 90 min at 1,152°C which is below the graphite eutectic temperature. However, the solidification of eutectic iron starts in about 5 min of holding and the solidification of hyper-eutectic iron is completed in the major part of the melt after 1 min of holding at the same temperature. The nucleation in the melt of hyper-eutectic iron is easier than the case with hypo-eutectic or eutectic iron at any degree of undercooling. This phenomenon is not considered to result from the different nucleation ability of carbon-microgroups existing in the melts produced from white irons containing various quantities of carbon reflecting the liquid structures of Fe-C system alloys. Rather it is considered to result from the effect of primary Fe3C in hyper-eutectic iron causing graphite precipitation from the eutectic melt due to the difference in solubility of Fe3C and graphite in liquid iron. Though the primary Fe3C partly dissolves into hyper-eutectic white iron molten above the Fe3C eutectic temperature and causes graphite prepicipitation, it still remains even when the melt is held as long as 60 min at 1,152°C.抄録全体を表示PDF形式でダウンロード (1124K) -
岩渕 義孝1983 年 55 巻 11 号 p. 683-687
発行日: 1983/11/25
公開日: 2011/12/13
ジャーナル フリーA study has been made of 13%Cr martensitic stainless cast steel containing 1% to 6%Ni as a function of hardness. The results were summarized as follows : (1) Toughness is raised with increased tempering temperature, exhibiting a maximum at around Ac1 temperature, and decreasing again at higher tempering temperature, while hardness changes inversely with toughness. (2) Upper shelf energy Em is a function of hardness. It is also a function of Ni content and tempering parameter P as expressed by the equation ; Em(kg-m)=−0.62Ni(%)+1.52P−13.92, where P=T(10+log t)×10−3 · (T : °K, t : hr). (3) Impact energy in the transition range is influenced by anstenite content and grain boundary embrittlement phenomena as well as by Ni content and tempering conditions.抄録全体を表示PDF形式でダウンロード (674K)
- |<
- <
- 1
- >
- >|