著者

前原 泰裕 小池 正夫 藤野 允克 邦武 立郎

出版者

The Iron and Steel Institute of Japan

雑誌

鉄と鋼 (ISSN:00211575)

巻号頁・発行日

vol.67, no.3, pp.577-586, 1981-03-01 (Released:2010-01-18)

参考文献数

33

被引用文献数

11 27

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Precipitation of σ phase in an Fe-25Cr-7Ni-3Mo alloy with a duplex structure of α and γ phases, has been studied systematically by means of optical microscopy, X-ray diffraction, hardness measurement, tensile test, SEM observation and dilatometric measurement. The results obtained in this study are as follows: (1) TTT diagram for the precipitation of σ phase was a C-type with a nose at about 820°C and 2030 min. (2) σ phase nucleated on the α/γ boundaries and grew into α grains, and thereafter the nucleation of σ and new γ phases began also in α grains. Volume fraction of α phase decreased and that of γ phase increased with increasing σ phase. Precipitation of σ phase occurred by the reaction, α→σ+γ. It was found that Cr, Mo and W were concentrated into α phase. (3) Increase of hardness with precipitation of α phase was not so large, on the contrary, impact value decreased drastically even at a few percent precipitation of α phase. α phase was also found to be harmful for hot ductility. (4) The precipitation range during cooling were about 700900°C and a phase precipitation could be avoided if cooling rate were larger than about 20°C/min after solution treatment. It was clarified from the above results that α embrittlement during production of duplex phase stainless steels could be avoided by selecting adequate manufacturing conditions.

著者

山口 哲夫 成田 宏 谷口 肇 松岡 孝 高橋 政司 平野 坦 高橋 栄治 山田 凱朗 尾内 三郎 田島 喜久雄 佐藤 進 泉 総一 子安 善郎 朝野 秀次郎 広前 義孝 大八木 八七 岡田 秀彌 細井 祐三 湯川 憲一 相崎 守弘 小若 正倫 佐武 二郎 諸石 大司 藤野 允克 松島 巖 上野 忠之 田中 良平 長崎 久弥 許廷 珪 大岡 新之 竹村 右 小原 啓一 長谷川 正義 藤山 新 竹中 康男 深瀬 孝重 遅沢 若一部 伊藤 穣一 岡本 一生 小野山 征生 太田 鶏一 高村 昭 荒川 要 坪井 孝悦

出版者

一般社団法人 日本鉄鋼協会

雑誌

鉄と鋼

巻号頁・発行日

vol.55, no.3, pp.S216-S224, 1969