TY - JOUR
T1 - Solute concentration and carbides formation for steel milling rolls
AU - Miyahara, Hirofumi
AU - Bravo, Sergio Villanueva
AU - Yamamoto, Kaoru
AU - Ogi, Keisaku
N1 - Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2009
Y1 - 2009
N2 - The selection and the formation of carbide govern quality and the service life of hot steel milling rolls. Thus the microsegregation and the formation of the carbides and the graphite during the solidification have been investigated for high speed steel type cast iron and Ni-hard type cast iron. The crystallization of high speed steel type cast iron proceeds in the order of primary austenite (γ), γ+MC and γ+M2C eutectic. On the other hand, in Ni-hard type cast iron, eutectic graphite flakes can crystallize after the formation of primary γ, and γ+M3C eutectic by controlling the content of Ni and Si in spite of containing strong carbide formers such as Cr. As γ+carbide eutectic grows, the residual liquid among eutectic cells becomes rich or poor in carbide formers according the partition coefficient between residual liquid and eutectic cell. It is realized that the change of composition of carbide formers during the solidification is estimated with Scheil-Gulliver equation and computed phase diagrams in both of cast irons. The graphite forming tendency is also evaluated by applying the parameter, which expresses the solubility limit of carbon to the molten iron for Ni-hard type cast iron.
AB - The selection and the formation of carbide govern quality and the service life of hot steel milling rolls. Thus the microsegregation and the formation of the carbides and the graphite during the solidification have been investigated for high speed steel type cast iron and Ni-hard type cast iron. The crystallization of high speed steel type cast iron proceeds in the order of primary austenite (γ), γ+MC and γ+M2C eutectic. On the other hand, in Ni-hard type cast iron, eutectic graphite flakes can crystallize after the formation of primary γ, and γ+M3C eutectic by controlling the content of Ni and Si in spite of containing strong carbide formers such as Cr. As γ+carbide eutectic grows, the residual liquid among eutectic cells becomes rich or poor in carbide formers according the partition coefficient between residual liquid and eutectic cell. It is realized that the change of composition of carbide formers during the solidification is estimated with Scheil-Gulliver equation and computed phase diagrams in both of cast irons. The graphite forming tendency is also evaluated by applying the parameter, which expresses the solubility limit of carbon to the molten iron for Ni-hard type cast iron.
UR - http://www.scopus.com/inward/record.url?scp=70350108843&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=70350108843&partnerID=8YFLogxK
U2 - 10.2355/isijinternational.49.1075
DO - 10.2355/isijinternational.49.1075
M3 - Article
AN - SCOPUS:70350108843
VL - 49
SP - 1075
EP - 1079
JO - Transactions of the Iron and Steel Institute of Japan
JF - Transactions of the Iron and Steel Institute of Japan
SN - 0915-1559
IS - 7
ER -