巻号一覧
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55 巻, 9 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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西辻 泰生, 津田 昌利1983 年 55 巻 9 号 p. 533-538
発行日: 1983/09/25
公開日: 2011/12/13
ジャーナル フリーThe influence of Al and AlN content upon the graphitization of white cast iron was investigated by repitition of heating and cooling. In white cast iron with low Si content, graphitization of about 0.55%Al specimen starts at about 1,000°C, and graphites precipitated are like snowflakes or starflakes. When Al content is over 1%, graphitization starts at about 650°C, and graphites precipitated are fine and granular. Aluminum nitride is also produced at the solid state and it reduces the solutionizied nitrogen which has the tendency of accelerating cementite crystallization. Graphitization of white cast iron and mottled cast iron containing Si starts at about 650°C, and graphites precipitated become finer. As Al content increase, the Ac1 transformation temperature rises.抄録全体を表示PDF形式でダウンロード (652K) -
堤 信久, 今村 正人, 羽田 晋介1983 年 55 巻 9 号 p. 539-545
発行日: 1983/09/25
公開日: 2011/12/13
ジャーナル フリーWith a view to investigating the effect of silicon on the spheroidization of graphite in spheroidal graphite cast iron, graphite form was changed while holding molten iron at high temperature, i.e. fading process in both cast iron with or without post-inoculation at given holding time of molten iron, the variation in the graphite form was observed with an image analyzing computer, following which silicon segregation was studied by potentio-static electrolytic etching. The position of eutectic crystallization in boundaries.
It has been clarified that the deterioration of graphite form appeared mainly on the primary graphite deposited at the matrix with high silicon content. It was also clarified that when sheroidity remained at a high level, the post-inoculation accelerated the spheroidization of graphite, but when it was at a low level C/V graphites formed. Moreover, it seems that fine graphites showing spheroidal form crystallize at eutectic cell boundaries with low silicon content, which are locations of the last stage of solidification. Subsequently, it has been concluded that the graphitization was accelerated by silicon inoculation, but the shape of graphite depended on both the difference of spheroidity and the difference of it being either primary or eutectic graphite.抄録全体を表示PDF形式でダウンロード (796K) -
相馬 詢, 長岡 金吾1983 年 55 巻 9 号 p. 546-551
発行日: 1983/09/25
公開日: 2011/12/13
ジャーナル フリーA quantitative metallographic analysis was made of the graphite phase at the center of the spheroidal graphite cast iron grown up to 10% in air by using the particle analyzer developed recently with the aim of establishing the growth theory of irreversible graphite migration more firmly, which was proposed by the authors. The graphite particle of 20-30 μm dia. was greatest in number in the distribution curve of ungrown cast iron and the shape of its distribution was similar to the normal distribution though the peak was a little off to the left. The largest size of graphite was 80-90 μm in dia. The number of graphite particles and the fractional area of graphite increased approximately in proportion to the growth. Especially the number below 10 μm dia. increased remarkably and the distribution curve gradually changed to the J-type. The largest graphite nodules also increased and reached 160-170 μm dia. after 10% growth. The number of graphite particles below 2 μm, dia. increased remarkably in proportion to the growth and reached 12.8 times that of ungrown iron after 10% growth. The metallographic analysis of spheroidal graphite cast iron grown up to 10% with the particle analyzer revealed quantitatively the redistribution of graphite particles in the new matrix adjacent to graphite nodules and the grown micro-voids around graphite nodules. This signified that the growth theory of irreversible graphite migration was also verfied in terms of quantiative microscopy.抄録全体を表示PDF形式でダウンロード (701K) -
芹田 陽1983 年 55 巻 9 号 p. 552-557
発行日: 1983/09/25
公開日: 2011/12/13
ジャーナル フリーFirst stage graphitization study was carried out by preparing different sizes of white iron specimen and examining the influence of casting size, slendering of specimen and reducing pressure of heating atmosphere on graphitization of white iron. It was clarified that graphitization was accelerated when casting size became small or when the specimen was slendered and heated under reduced atmospheric pressure. It was considered that graphitization originates from nucleating graphite at a void constructed during graphitization heating.抄録全体を表示PDF形式でダウンロード (634K) -
桑野 正司, 大城 桂作, 松田 公扶1983 年 55 巻 9 号 p. 558-564
発行日: 1983/09/25
公開日: 2011/12/13
ジャーナル フリーThe influence of destablization heat treatment on eutectoid transformation of high chromium cast irons containing 1.5∼4%C, 6.5∼26%Cr, 1∼3%Mn and 0.5%Si was investigated with the dilatometer. The specimens destabilized at 1.000°C for 100 min or 6,000 min were cooled to room temperature at rates ranging from 20 to 0.008°C/sec. During cooling, the changes in length and temperature of the specimen were measured to obtain the continuous cooling transformation diagrams. The pearlite noses were located in the range of 580∼650°C. The nose temperature was not much affected by the chemical composition and the condition of destabilization heat treatment. The critical cooling rate became smaller as the chromium concentration in austenite increased. In the specimens containing chromium and carbon at the ratio of 8.5 : 1 in which the chromium concentration in homogenized austenite was in excess of 8%, the critical cooling rate became larger with the progress of the precipitation of the secondary carbides accompanying longer destabilization heat treatment. The increase in manganese content of alloy lowered the critical cooling rate. The measured Vickers microhardness of the transformed matrix corresponded closely with the continuous cooling transformation diagram of the specimen.抄録全体を表示PDF形式でダウンロード (719K)
研究部会報告
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木下 禾大1983 年 55 巻 9 号 p. 578-581
発行日: 1983/09/25
公開日: 2015/01/27
ジャーナル フリーPDF形式でダウンロード (2111K)
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