著者

川本 正幸 柳楽 知也

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.100, no.4, pp.472-484, 2014

被引用文献数

10

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The continuous casting technology of steels in Japan has been well-developed over the past 60 years since the introduction of a continuous casting machine and its technology from Europe. The continuous casting ratio of steels has reached over 98%. A large number of researchers have been conducted on fundamental researches for the improvement of continuous casting technologies. Some of the development histories are summarized in the book, entitled ìHistory of Steel Continuous Casting Technology in Japanî in 1996. In recent years, a near-net-casting has been also developed for higher efficiencies and productivity in many countries. This paper reviews the histories of development in the continuous casting in Japan on technologies regarding (1) Pouring to mold, (2) mold lubrication, (3) cooling of a solidifying shell, (4) machine type, (5) reduction of casting defects, (6) tundish, (7) measurement and control processes and (8) different types continuous castings. The fundamental researches on the major casting defects including macrosegregation, cracking and inclusions that are formed in a continuous casting are also reviewed. Some brief comments on the further development of continuous casting in the future are described.

著者

杉山 明 安田 秀幸 柳楽 知也 吉矢 真人 上杉 健太朗 梅谷 啓二 大中 逸雄

出版者

公益社団法人 日本鋳造工学会

雑誌

鋳造工学 = Journal of Japan Foundry Engineering Society (ISSN:13420429)

巻号頁・発行日

vol.83, no.3, pp.131-136, 2011-03-25

参考文献数

11

被引用文献数

1

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It is well known that controlling the graphite shape in cast iron is a critical issue to achieve appropriate properties. It is of interest to know how the microstructure in cast iron evolves during solidification. So far, time-evolution of the microstructure has not been observed in-situ. This paper presents the in-situ observation results of cast iron solidification using X-ray imaging of synchrotron radiation. Transmission X-ray images with a spatial resolution of as small as 5<i>μ</i>m were obtained by an X-ray detector SATICON in an imaging beam line 20B2 at SPring-8. A 10 × 10 × 0.1mm specimen was melted and solidified in a mold made of Al₂O₃ placed in a vacuum chamber. The observation showed that the solidification started with austenite dendrites, after which the eutectic structure was formed. Graphite clusters of about 100<i>μ</i>m in diameter were formed in the remaining liquid surrounded by the eutectic structure at a cooling rate of less than 10K/min. At a cooling rate of 10K/min, the primary dendrite and the eutectic grains moved up and down, respectively, due to the bouncy force.

著者

杉山 明 前川 裕貴 後藤 耕太 山根 功士朗 安田 秀幸 吉矢 真人 柳楽 知也 牛込 智章 佐藤 彰洋 梅谷 啓二 上杉 健太朗

出版者

公益社団法人 日本鋳造工学会

雑誌

鋳造工学 全国講演大会講演概要集 第161回全国講演大会講演概要集 (ISSN:18805388)

巻号頁・発行日

pp.13, 2012 (Released:2017-03-01)

著者

上部 伊織 道原 健人 森下 浩平 柳楽 知也 安田 秀幸

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.103, no.12, pp.678-687, 2017 (Released:2017-11-30)

参考文献数

27

被引用文献数

5

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This study demonstrates in-situ measurement of solute partition coefficient in multicomponent alloys, using X-ray transmission imaging and X-ray florescence spectroscopy. The developed technique was applied to determine partition coefficients of Cr, Ni and Mo between δ phase and liquid phase in Fe-17.4Cr-12.6Ni-2.0Mo-1.6Mn-0.6Si alloys (mass%). In the observation and measurement, X-ray fluorescence spectra were directly obtained by irradiating the incident X-ray beam (23keV) to the solid phase or the liquid phase near solid/liquid interface. The partition coefficients were simply determined from the X-ray florescence analysis. In addition, successive measurements during unidirectional solidification allowed to measure change in partition coefficient along solidification path. During the solidification, partition coefficients of Cr, Ni and Mo changed from 1.01 to 1.08, from 0.76 to 0.70 and from 0.86 to 0.74, respectively. The present study proved that the developed technique was applicable to determine partition coefficients of 3d and 4d transition elements of which characteristic X-ray energies ranged from 4 to 20keV.