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Effects of Si and Mo on the Temperature-Dependent Properties of High Si High Mo Ductile Cast Irons  

Choe, Kyeong-Hwan (Korea Institute of Industrial Technology)
Lee, Sang-Mok (Korea Institute of Industrial Technology)
Kim, Myung-Ho (Inha University)
Yun, Sang-Weon (Castec Korea Co., Ltd)
Lee, Kyong-Whoan (Korea Institute of Industrial Technology)
Publication Information
Journal of Korea Foundry Society / v.29, no.6, 2009 , pp. 257-264 More about this Journal
Abstract
The effects of silicon and molybdenum on the temperature-dependent properties of high silicon and high molybdenum ductile cast iron were investigated. Microstructure was composed of ferrite, cell boundary complex carbide, carbide precipitated in the grain and graphite. The number and size of carbide decreased with the increase of silicon content and increased with the increase of molybdenum content, however, the size of cell boundary carbide increased above 0.81wt%Mo. The room temperature tensile strength increased with the increase of silicon and molybdenum contents. That did not increase with the latter with more than 0.8wt%. Meanwhile the high temperature tensile strength showed the similar trend to that of room temperature one, that of the specimen with 0.55wt%Mo was the highest. The $A_1$ transformation temperature increased with the silicon and molybdenum contents, and showed similar tendency with the variation of strength. It was discussed due to the solubility limit of Molybdenum in ferrite, of which value was assumed to be in the vicinity of 0.81wt%Mo. The weight after oxidation at 1,173K showed the result caused by the difference in solubility of molybdenum in the matrix. That and the thickness change after oxidation did not show any consistent trend with the silicon and molybdenum contents.
Keywords
Si-Mo ductile iron; Si and Mo addition; High temperature strength; Oxidation behavior; Thermal expansion;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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1 H. I. Park and H. Y. Jeong: J. Kor. Foundrymen's Soc., "High temperature properties of vanadium and molybdenum added high silicon ductile iron", 27(5) (2007) 203-208
2 S. W. Kim, K. D. Woo, S. W. Han and J. K. Kim: Proc. of KSAE, "A development of high Si DCI with heat resistance and high temperature oxidation resistance properties for automobile parts", (1996) 3-10
3 S. H. Park, J. M. Kim, H. J. Kim, S. J. Ko, H. S. Park and J. D. Lim: "Development of a heat resistant cast iron alloy for engine exhaust manifolds", SAE 2005-01-1688 (2005)
4 J. D. Mullins: "Ductile Iron Data for Design Engineers", Rio Tinto Iron & Titanium Inc., (1990)
5 F. B. Pickering and T. Gladmann: ISI Special Report No. 81, (1963), 10
6 H. J. Bang: J. Kor. Foundrymen's Soc., "Ductile Cast Irons for Elevated Temperature Service", 12(2) (1992) 102-107
7 B. Black, G. Burger, R. Logan, R. Perrin and R. Gundlach: "Microstructure and dimensional stability in Si-Mo ductile irons for elevated temperature applications", SAE 2002-01-2115 (2002)
8 K. Maruyama and H. Nakashima: "Materials Science of High Temperature Strength" (1997), 189
9 "High temperature materials for exhaust manifold", SAE Standard J 2515, SAE (1999)
10 L. -E. Bjorkegren, H. Hamberg and B. Johannesson: AFS Trans. "Mechanical Properties and Machinability of Si-Solution-Hardened Ferritic Ductile Iron", 104 (1997) 139-146
11 D. L. Sponseller, W. G. Scholz and D. F. Rundle: AFS Trans., "Development of Low-Alloy Ductile Irons for Service at 1200-1500F", 76 (1968) 353-368
12 J. Y. Kim and H. Y. Ra: J. Kor. Foundrymen's Soc., "The Effects of Si and Mo on the Structures and Mechanical Properties in High Si Spheroidal Graphite Cast Iron", 10(3) (1990) 225-234
13 D. Li, R. Perrin, G. Burger, D. McFarlan, B. Black, R. Logan and R. Williams: "Solidification Behavior, Microstructure, Mechanical Properties, Hot Oxidation and Thermal Fatigue Resistance of High Silicon SiMo Nodular Cast Irons", SAE 2004-01-0792 (2004)
14 N. Suzuki, S. Ishizuka, Z. Z. Zhang and N. Akita: J. JSAE, "Development of Vanadium-added heat resistant cast iron for exhaust manifold", 28 (2003) 108-112
15 American Foundrymen's Society: "Ductile Iron Handbook" (1993), 88
16 K. Ogi, A. Sawamoto and J. Hiwatashi: "Transformation Process and Behavior of Carbon in Austempering Heat Treatment of Spheroidal Graphite Cast Iron", 60(4), (1988) 233-239
17 S. W. Kim, K. D. Woo, S. W. Han, J. K. Kim and D. Y. Kim: J. Kor. Foundrymen's Soc., "The study on high Si and Mo DCI with high temperature oxidation resistance property", 18(2) (1998) 63-69
18 D. Li and R. Logan: "High Silicon Cast Iron with Mixed Graphite (MG) Shape for Elevated Temperature Applications", SAE 2007-01-1227 (2007)
19 H. Tsuda, N. Suzuki, S. Ishuzuka and T. Kurikuma: J. JFS, "Effect of Molybdenum and Vanadium on properties at elevated temperature of high silicon spheroidal graphite cast iron", 76(10) (2004) 815-822