Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
권호 표지

Morphology and Segregation of Sulfide Inclusions in Cast Steels (II) (Influence of [Mn/S] Ratios on the Morphology of Sulfide Inclusions in Fe-Mn-S Alloys)

주강의 유화물 형태와 편석에 대한 연구 (II) (Fe-Mn-S 합금의 유화물 형태에 미치는 Mn/S비의 영향)

  • Park, Heung-Il (Department of materials processing engineering, Graduate school, Pukyung National University) ;
  • Kim, Ji-Tae (Samyoung M-Tek Co., Ltd.) ;
  • Kim, Woo-Yeol (Department of materials processing engineering, Graduate school, Pukyung National University)
  • 박흥일 (부경대학교 대학원 소재프로세스공학과) ;
  • 김지태 (삼영엠텍(주)) ;
  • 김우열 (부경대학교 대학원 소재프로세스공학과)
  • Published : 2009.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

After casting button-type small ingots of ternary Fe-Mn-S alloys which had three different Mn/S ratios (1, 5 and 70) in a vacuum arc furnace, the effect of the ratio on the sulfide formation was investigated. In case of the Mn/S ratio of 1, if alloy composition was located in an iron-rich corner on a Fe-Mn-S ternary phase diagram, only duplex MnS-FeS sulfide films were observed in the grain boundary. If the alloy composition was located in the miscibility gap area of the phase diagram, primary globular dendritic sulfides and dendritic sulfide slags were generated within the grain and tubular monotectic sulfides were also detected in the grain boundary. When the Mn/S ratio was 5, if the alloy composition was in the iron-rich corner, only bead-like sulfides were generated. On the other hand, if the composition was in the miscibility gap area, globular dendritic sulfides and dendritic sulfide slags were generated in the form of primary sulfide inclusions and rod-like eutectic sulfides were observed in the grain boundary. Especially, if the contents of Mn and S increased more in the miscibility gap area of the phase diagram, primary globular sulfides containing iron intrusions were observed. In case of Mn/S ratio of 70, if the contents of Mn and S was decreased in the Fe corner of the phase diagram, only bead-like sulfides were observed in the grain boundary. Despite the composition was outside the miscibility gap area of the phase diagram, if the contents of Mn and S increased, clusters of fine sulfide particles as well as fine spherical primary monophase sulfides were observed in the grain boundary.

Keywords

References

  1. J. K. Brimacombe and K. Sopimachi, "Crack formation in the continuous casting of steel", Metallurgical transactions B, Vol.8B (1977) 489-505
  2. C. L. Briant and S. K. Banerji, "Intergranular failure in steel: the role of grain-boundary composition", International metals reviews, No.4 (1978) 164-199
  3. A. Chojecki, I. Telejko and T. Bogacz, "Influence of chemical composition on the hot tearing formation of cast steel", Theoretical and applied fracture mechanics, Vol.27 (1997) 99-105 https://doi.org/10.1016/S0167-8442(97)89529-8
  4. ASM Handbook, Vol. 6 (1997) 88-106 "Cracking phenomena associated with welding"
  5. A. Chojecki, I. Telejko and P. Kozelsky, "Influence of calcium on cracking of steel during the welding or casting process", Theoretical and applied fracture mechanics, Vol.31 (1999) 41-46 https://doi.org/10.1016/S0167-8442(98)00065-2
  6. L. H. Van Vlack, O. K. Riegger and R. J. Warrick, "Sulfide inclusions in steel", The University of michigan reserch institute, UMRI project report, (1958)
  7. W. Dahl, H. Hengstenberg and G. Dueren, "Conditions for the occurance of the various types of sulphide inclusions", Stahl und Eisen, Vol. 86, No. 13 (1966) 782-795
  8. G. Wranglen, "Review article on the influence of sulphide inclusions on the corrodibility of Fe and steel", Corrosion Science, Vol.9 (1969) 585-602 https://doi.org/10.1016/S0010-938X(69)80114-9
  9. C. E. Sims, F. B. Dahle, "Effect of Aluminum on the Properties of Medium Carbon Cast steel",Transactions of the American Foundrymen's Association, Vol.46 (1938) 65-132
  10. C. E. Sims, H. A. Saller and F. W. Boulger, "Effects of various deoxidizers on the structures of sulphide inclusions", Transactions, American Foundry Society, 57 (1949) 233-248
  11. C. E. Sims, "The nonmetallic constituents of steel", Transactions of the metallurgical society of AIME, Vol.215 (1959) 367-392
  12. E. T. Turkdogan, S. Lgnatowicz and J. pearson, "The solubility of sulphur in iron and iron manganese alloys", J. of iron and steel institute, (1955) 349-354
  13. G. S. Mann and L. H. Van Vlack, "FeS-MnS relationships in the presence of excess iron", Metallurgical transactions B, Vol.7B (1976) 469-475
  14. E. T. Turkdogan, "Fundmentals of steelmaking", The institute of materials, (1996) 307
  15. G. A. Teledo, Influence of sulfur and Mn/S ratio on the hot ductility of steels during continuous casting", Steel research, Vol.64, No.6 (1993) 292-299 https://doi.org/10.1002/srin.199301025
  16. H. Nakata and H. Yasunaka, "Effect of sulfur and manganese on hot ductility of steels at high temperature", Transactions ISIJ, Vol. 26 (1986) B-98
  17. H. I. Park, J. T. Kim and S. G. Kim "Morphology and segregation of sulfide inclusions in cast steels (I); A fabrication of Fe-FeS alloys and the observation of their sulfide morphology." J. of the Korean Foundrymen's Society, Vol.29, No.5 (2009) 220-224
  18. H. I. Park et al, "A case study on the solidification behavior and defects of heavy steel castings", J. of the Korean Foundrymen's Society, Vol.26, No.2 (2006) 57-62
  19. L. K. Biglow and M. C. Flemings, "Sulfide inclusions in steel", Metallurgical Trans. Vol. 6B (1975) 275-283
  20. K. Oikawa, et al., "The control of morphology of MnS inclusions in steel during solidification", ISIJ International, Vol.35, No.4 (1995) 402-408
  21. H. Fredriksson and Hillert, "On the Formation of Manganese Sulfides Inclusions In Steel, Scandinavian Journal of Metallurgy, 2 (1973) 125-145
  22. H. Wentrup, "Die Bildung von Eissenschuessen im Stahl", Technische Mitteilung Krupp, Vol.5 (1937) 131-152