http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Nucleation of Graphite in Cast Irons
( Carl R . Loper ) 한국주조공학회 1997 한국주조공학회지 Vol.17 No.4
The current understanding of the mechanism of inoculation of the eutectic in commercial Fe-C-Si alloys using either silicon containing alloys or graphite has been discussed. The mechanism whereby inclusion formation within a cast iron melt is essential for inoculation effectiveness in ferro silicon inoculation has been reviewed. The role of graphitic inoculants has been presented, including the results of recent research that confirms the inoculating capability of graphite and demonstrates those factors which must be considered in evaluating inoculation effectiveness. Fading of inoculation, both ferro silicon and graphite, and the mechanism whereby this occurs, has also been discussed.
On the Mechanism of the Formation of Widmanstatten Graphite in Flake Graphite Cast Irons
Jr Carl R.Loper,Park, Junyoung 대한금속재료학회 2003 METALS AND MATERIALS International Vol.9 No.4
The mechanism whereby Widmanstatten graphite develops during the solidification of flake graphite cast irons has been found to involve the preferential segregation and a complex interaction of specific elements at the surface of the graphite flake during solidification and the development of the plate like appendages in the solid austenite adjacent to the graphite flake. The literature has suggested that lead, calcium and hydrogen may bc causal to the formation of Widmanstatten graphite. hut has the interaction of these elements has not been effectively documented. While the formation of this degraded graphite is often attributed to the presence of a sufficient amount of lead alone, it has been observed that Widmansatten graphite develops only in conjunction with a combination of factors operative at the graphite-austenite intertace. Commercial flake graphite cast irons may exhibit Widmanstatten graphite as a function of lead and calcium content in the iron, moisture content in the molding media, solidification cooling rate and the rate of cooling immediately after solidification, etc. Lead contamination of cast irons was also observed to increase the chilling tendency of the iron. The detrimental effects of lead can be counteracted by the presence of rare earths in the iron, where rare eanh elements react with lead to form stable. high melting point compounds.
유수안,Yew, S. A. 대한금속재료학회(대한금속학회) 1969 대한금속·재료학회지 Vol.6 No.4
灰鑄鐵의 初晶 dendrite를 볼 수 있는 方法을 發展시킴으로서 灰鑄鐵의 機械的性質과 初晶 dendrite, 共晶 cell, 共晶組織, 黑鉛等과의 關係를 硏究하였다. 方向性이 좋고 稠密한 初晶 dendrite가 잘 發達한 共晶 組織을 同伴하는 것이 方向性이 없고 稠密치 못한 dendrite가 未發達한 共晶組織을 同伴할 때 보담 機械的性質이 優秀하다. 初晶 dendrite는 그 凝固機構에 따라 Type I, Type II, Type III로 分類한다. Type I dendrite는 그 凝固過程에서 充分한 發達을 할 수 있으므로서 잘 發達한 共晶組織을 同伴하고 Type II dendrite는 凝固過程이 억압됨으로서 잘 發達하지 못한 共晶組織을 同伴하고 또 Type III dendrite는 高溫에서 凝固가 進行되어 오히려 發達할 機會를 갖지 못한 未發達된 共晶組織을 同伴한다. 灰鑄鐵의 黑鉛組織도 發達, 未發達, kish등 3種類로 分類할 것을 提案한다. Developing method of sample treatment for proeutectic dendrites, study a relationship between proeutectic dendrites, eutectic cell structures, eutectic structures, graphite structures and mechanical properties of gray cast iron. Hightly oriented and compact proeutectic dendrites with well developed eutectic structures have higher mechanical properties than random dendrites with underdeveloped eutectic structures. Proeutectic dendrite structures be classified according to the solidification mechanism, as Type I, II, and III. Type I dendrites associate well developed eutectic structures due to enough chance to develope during the solidification. Type II dendrites associate underdeveloped eutectic structures due to suppression of the solidification reaction. Type III dendrites associate underdeveloped eutectic structures due to lack of chance to develope at higher temperature solidification. Graphite structures of gray cast iron have proposed to be classified as developed, underdeveloped and kish graphite.