Graduate School of Systems Engineering, Kinki University.
Department of Mechanical Engineering, Faculty of Engineering, Kinki University
Department of Mechanical Engineering, Faculty of Engineering, Kinki University
Castem, Co., Ltd
版
publisher
出版者 名前
近畿大学工学部
出版社 カナ
キンキ ダイガク コウガクブ
出版社 ローマ字
Kinki daigaku kogakubu
出版年(from)
2009
出版年(to)
12-21
日付 作成日
2010-05-20
雑誌名
近畿大学工学部研究報告
雑誌名(英)
Research reports of the Faculty of Engineering, Kinki University
号
43
ページ
43 - 53
発行年
2009-12-01
ISSN
0386491X
抄録
In this study,we systematically investigate on the influence of additional carbide stabilizer elements,M (M=V, Ti or Nb) on the amount, morphology and distribution of crystallized M_7C_3 and/or MC type carbides in alloy tool steel (SKD11 of JISG4404) castings during solidification. The base chemical compositions of the steel castings,produced by the investment casting process are 1.5 mass% C,12 mass% Cr and 0.3 mass% V. The castings were melted in a high frequency induction furnace and melts varying from 0.3 mass% V to 5 mass% V,from 0.5 mass% Ti to4 mass% Ti and from 0.5 mass% Nb to 5 mass% Nb were cast into an alumina mould 14 mm in thickness,heated to 1,373K. Microstructure of steel casting without addition of carbide stabilizer elements M consists of dendritic iron matrix and continuous plate-like eutectic (Fe,Cr)_7C_3 carbide. With increasing M cont.ent, crystallized carbide in the castings were found to change from (Fe,Cr)_7C_3 type to granular MC type,crystallizing randomly owing to stronger stabilization of the carbide of M than Cr. Therefore,( Fe,Cr)_7C_3 carbide is dispersed or separated by crystallization of MC type. The dispersing or separating situation is remarkable in the order to V <Nb<Ti addition. From analytical results of distribution of elements by energy dispersive X-ray (EDX) analysis, and detection and identification of carbides by X-ray diffractometry,crystallized MC type carbides constitute VC, TiC or NbC type ones, corresponding to additional elements M of V, Ti or Nb