巻号一覧
後続誌
58 巻, 4 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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技術報告
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山本 志郎, 佐伯 啓治, 広瀬 豊, 竹林 一成, 川崎 正寿1986 年 58 巻 4 号 p. 256-260
発行日: 1986/04/25
公開日: 2015/01/27
ジャーナル フリーPDF形式でダウンロード (2198K)
研究論文
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大出 卓, 御田 潤一, 井川 克也1986 年 58 巻 4 号 p. 261-267
発行日: 1986/04/25
公開日: 2011/10/25
ジャーナル フリーThe relationship among carbon equivalent value, mechanical properties and ultrasonic velocity of some cast irons was investigated. Ultrasonic velocity decreases with an increase of CE value, and increases as graphite transforms from flaky to CV and spheroidal. As-cast flaky, CV and spheroidal graphite cast irons having standard chemical compositions have average ultrasonic velocity 4,500, 5,400 and 5,600m/s respectively. Both tensile strength and Brinell hardness increase with an increase of the velocity. These properties are easily estimable by indirectly measuring ultrasonic velocity. A closed correlation lies between tensile strength which depends on graphite quantity, graphite form and matrix structure, and the product of the ultrasonic velocity which is governed by the amount and form of graphite and the Brinell hardness which is governed by the graphite amount and matrix structure. A deformation behavior of cast iron under tensile loading approximately corresponds to the velocity change.抄録全体を表示PDF形式でダウンロード (778K) -
南 和一郎, 千々岩 健児1986 年 58 巻 4 号 p. 268-274
発行日: 1986/04/25
公開日: 2011/10/25
ジャーナル フリーEquations were derived for the process in which liquid metal flows through a multigating system into multiple cavities considering heads of sprue and cavities. An analizing model was estimated by water model analogue through two ingates. Experimental data were compared with calculated ones. The sprue head rises with oscillation at the initial pouring stage. This oscillation intensifies as the gating ratio increases and the flow rate lowers. If the cavities are of identical configulation, all heads linearly rise nearly at the same rate. If the cavities have different diameters, a difference in head height occurs in the initial stage of liquid metal pouring into the cavities. If the cavities have different heights, liquid levels of the ingate and other cavities change, and the velocity at the ingate rapidly accelerates as the lower cavity is filled.抄録全体を表示PDF形式でダウンロード (684K) -
村上 信義, 小林 俊雄, 大和田野 利郎1986 年 58 巻 4 号 p. 275-280
発行日: 1986/04/25
公開日: 2011/10/25
ジャーナル フリーWear of cast iron and steel by sand erosion was measured in water and artifcial sea water in which molding sand had been mixed. The effect of cathodic protection by contact with zinc was examined. Relationship of wear loss by sand erosion G(gf/cm2/h) and Vickers hardness Hv is expressed as G=K/HVn, where K and n are constants. n is close to unity nearly abrasive wear condition, but decreases as the corrosive wear condition is potentiated. Cast iron shows larger wear loss than steel. A number of small pits from which graphite has fallen off by impact of sand particles in a short time promote the corrosion rate and shear force. The cathodic protection by contact with zinc is not so effective in water, but is successful in artificial sea water particularly for cast iron. This is probably caused by that successional growth of the pits and subsequent occurrence of pits by chemical corrosion are limited in artificial sea water by the effect of cathodic protection.抄録全体を表示PDF形式でダウンロード (685K) -
神戸 洋史, 社本 裕幸, 畑 知克, 雄谷 重夫1986 年 58 巻 4 号 p. 281-286
発行日: 1986/04/25
公開日: 2011/10/25
ジャーナル フリーApparent viscosity of solidifying Cu-Sn alloys was measured from the liquid state successively by the torsional oscillation method. The apparent viscosity increases gradually in the initial stage of solidification and abruptly at completion of the dendrite skelton. The apparent viscosity in the initial stage shows practical viscosity of bulk solidliquid phase. While, that after abrupt increase is a parameter showing resistance of the rigid dendrite skelton to the microscopic flow of residual liquid. A concept “hydraulic radius“ showing an interskelton spacing is introduced in the latter stage. A closed correlation between hydraulic radius and fraction solid at a moment of abrupt increase in apparent viscosity shows a critical condition to transfer from bulky flow of the solid-liquid phase to interskelton one. The shape of solidifying primary solids governs the apparent viscosity of solid-liquid mixture and easiness of dendrite skelton forming. Preferred growth of dendrites in the arm direction leads to high apparent viscosity and abrupt increase in viscosity at lower fraction of solid.抄録全体を表示PDF形式でダウンロード (688K) -
小林 俊郎, 新家 光雄, 山本 浩喜1986 年 58 巻 4 号 p. 287-292
発行日: 1986/04/25
公開日: 2011/10/25
ジャーナル フリーDuctile irons with various prior-structures such as as-cast bull's eye structure, ferrite and pearlite ones to which Ni and Mn had been added were austempered from different austenitizing temperatures including the (α+γ) range in order to achieve preferable conditions for strengthening. An as-cast matrix structure with bull's eye austempered from the (α+γ) range exhibits a preferable combination of the highest strength and toughness. This is probably caused by a large amount of stable retained austenite particularly in such fracture starting sites as graphite-matrix interfaces and eutectic cell boundaries. The stable austenite is introduced by i) local stabilizing at graphite-matrix interfaces by supplying carbon from graphite nodules and microsegregation of Ni, and ii) local stabilizing at eutectic cell boundaries by rapid solutioning of cementite and microsegregation of Mn.抄録全体を表示PDF形式でダウンロード (786K) -
堤 信久, 藤長 政志, 鈴木 一1986 年 58 巻 4 号 p. 293-299
発行日: 1986/04/25
公開日: 2011/10/25
ジャーナル フリーThe influence of a small amount of alloying elements such as Sn, Sb and Cu on the Ar1 transformation of spheroidal graphite cast iron was analyzed by using a specially designed dilatometer by which differential thermal variation and dilatometric change are simultaneously measurable during cooling in the temperature range of Ar1 transformation. Apple II type mini-computer is connected to the dilatometer to ensure flatness of the dilatometric curve and to calibrate the differential thermal curve. A small percent addition of Sn and Sb shift the nose in continuous cooling transformation curve of the iron to longer time by suppressing the precipitation of carbon from austenite onto existing spheroidal graphite nodules. Copper addition stabilizes, however, pearlitic matrix by lowering the temperature of direct graphitization from austenite. Sn and Sb suppress super cooling in pearlitic transformation of the iron and rise the temperature level of transformation.抄録全体を表示PDF形式でダウンロード (728K)
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