Materials Transactions Online

Materials Transactions, Vol.57 No.12 (2016) pp.2132-2138
© 2016 Japan Foundry Engineering Society

Influence of Silicon Content, Strain Rate and Temperature on Toughness and Strength of Solid Solution Strengthened Ferritic Ductile Cast Iron

Tomohiro Ikeda1, Takuo Umetani1, Nobuhiro Kai1, Keisaku Ogi1, Nao-Aki Noda2 and Yoshikazu Sano2

1Research & Development Center, HINODE, Ltd., Saga 849-0101, Japan
2Department of Mechanical and Control Engineering, Kyushu Institute of Technology, Fukuoka 804-8550, Japan

High Silicon Solid Solution Strengthened Ferritic Ductile Cast Iron possesses advantages, such as better combination of strength-elongation, higher fatigue strength, smaller section thickness sensitivity, higher machinability etc., over conventional ferrite-pearlite type ductile cast iron. However, industrial application of high Si ductile cast iron is still very limited, because of the lower Charpy impact value at room temperature. As the toughness of iron strongly depends on the strain rate as well as temperature, dynamic three-point bending tests are conducted on 3~4%Si ferritic ductile cast iron at stroke speed of 10−3~102 mm/s, and at −20~22℃. The relations of the crack initiation energy Ei, the crack propagation energy Ep, the total absorbed energy Et and the maximum bending stress σb,max to the strain rate show abrupt dropping of these characteristic values at critical strain rate, depending on silicon content and test temperature. σb,max keeps increasing with increasing strain rate $\dot{\varepsilon}$ as far as the fracture origin is ductile, it slightly decreases over $\dot{\varepsilon}_\sigma = \dot{\varepsilon}_{fD}$ where the dimple fracture completely disappears. σb,max, Et and Ei of each silicon iron is well expressed in relation to strain rate-temperature parameter R, T ln(A/$\dot{\varepsilon}$). The critical R values for Et, Ei, and σb,max (Rt, Ri and Rσ) decrease linearly with decreasing the silicon content of iron. The critical value for σb,max (Rσ) is lowest, indicating Rσ gives a wider design tolerance.

[doi:10.2320/matertrans.F-M2016832]

(Received 2016/04/25; Accepted 2016/09/02; Published 2016/11/25)

Keywords: high silicon ductile cast iron, ferritic matrix, dynamic strength, toughness, strain rate, temperature

PDF(member)PDF (member) PDF(organization)PDF (organization) Order DocumentOrder Document Table of ContentsTable of Contents

REFERENCES

  1. R. Larker: China Foundry 6 (2009) 343-351.
  2. R. Larker: Proc. NEWCAST Forum, (Bundeseverband der Deutschen Gießerei Industrie, 2011), p.29.
  3. H. Löblich: Proc. Deutscher Gießereitag 2013 und 5.NEWCAST Forum, (Verein Deutscher Giessereifachleute, 2013), pp.14-17.
  4. EN 1563: Founding-Spheroidal graphite cast irons, 2011.
  5. T. Umetani, T. Ikeda, N. Sura, K. Ashizuka, T. Nemoto, H. Takada and K. Ogi: J.JFS. 86 (2014) 36-42.
  6. T. Okumoto and T. Aizawa: Imono 35 (1963) 670-677.
  7. K. Nagai, K. Kishitake and T. Owadano: Imono 58 (1986) 350-355.
  8. H. Nagayoshi, H. Yasuda and K. Imanishi: J.JFS. 68 (1996) 506-511.
  9. H. Yamamoto, T. Kobayashi and H. Fujita: J.JFS. 72 (2000) 107-112.
  10. K. Nagai, S. Izumi, K. Kishitake and T. Owadano: Imono 58 (1986) 653-658.
  11. JIS-G5502: Spheroidal graphite iron castings, 2001.
  12. JIS- G 0551: Steels-Micrographic determination of the apparent grain size, 2005.
  13. JIS-Z 2243 standard: Brinell hardness test-Test method, 2008.
  14. JIS-Z2241: Metallic materials-Tensile testing-Method of test at room temperature, 2011.
  15. T. Shiota, T. Matuoka and S. Komatu: Imono 63 (1991) 601-606.
  16. JIS-Z2242: Method for Charpy pendulum impact test of metallic materials, 2005.
  17. R. Sandstrom and Y. Bergstrom: Met. Sci. 18 (1984) 177-186.
  18. N. Sugiura, T. Kobayashi, I. Yamamoto, S. Nishido and K. Hayashi: J. Jpn. Inst. Light Met. 45 (1995) 638-642.
  19. K. Matsugi, G. Bando, G. Sasaki and O. Yanagisawa: J.JFS. 79 (2007) 229-234.
  20. T. Kobayashi, H. Matsubara and Y. Ueda: Tetsu-to-Hagane 69 (1983) 1183-1188.
  21. S. Nunomura and M. Nakashiro: Tetsu-to-Hagane 64 (1978) 860-869.
  22. T. Nobuki, T. Shiota and M. Hatate: J.JFS. 75 (2003) 749-756.
  23. T. Nobuki, T. Shiota and M. Hatate: J.JFS. 76 (2004) 555-561.
  24. P.E. Bennett and G.M. Sinclair: Trans. ASME 65 (1966) 518-524.
  25. E. Fuji, Y. Ohkuma, Y. Kawaguchi and M. Tsukamoto: The society of naval architects of Japan 158 (1985) 619-629.
  26. K. Goto, H. Hirosawa and M. Toyoshada: The society of naval architects of Japan 176 (1994) 501-507.
  27. F. Minami, T. Hashida, M. Toyoda, J. Morikawa, T. Ohmura, K. Arimochi and N. Konda: The society of naval architects of Japan 184 (1998) 453-463.
  28. H. Yamamoto, T. Kobayashi and H. Fujita: Tetsu-to-Hagane 85 (1999) 765-770.
  29. M. Toyosada, E. Fujii, K. Nohara, Y. Kawaguchi, K. Arimochi and K. Isaka: The society of naval architects of Japan 161 (1997) 343-356.


[JIM HOME] [JOURNAL ARCHIVES]

© 2016 Japan Foundry Engineering Society
Comments to us : editjt@jim.or.jp