The Effect on the Strength According to Carbon Content of Kovar Steel

코바강의 탄소첨가량에 따른 강도에 미치는 영향

  • Choi, Byung-Hui (Department of Automobiles, Chosun University College of Science & Technology) ;
  • Choi, Byung-Ky (Department of Mechanical Engineering, Chosun University)
  • 최병희 (조선이공대학 자동차과) ;
  • 최병기 (조선대학교 기계공학과)
  • Received : 2010.01.26
  • Accepted : 2010.05.16
  • Published : 2010.06.30

Abstract

Ni alloy steel is able to use during long time because of good acid and corrosion resistance. So, it's research has focused on developing the alternative alloy which is economically feasible. Recently, consumption of Kovar steel is gradually increased in field of the jet engine and the gas turbine because of its low thermal expansive characteristics. The specimens of Kovar steel(29%Ni-17%Co) contain 0.00%C, 0.03%C, 0.06%C, 0.10%C and 0.20%C, respectively. Ingots are manufactured by VIM(vacuum induction melting furnace) and then specimens are made by automatic hot rolling after heat treatment. Strength of Kovar steel according to carbon contents is estimated by hardness, tensile and impact test. Hardness of the 0.20%C specimen is more improved approximately 14.4% than one of base metal. Its strength increases 32.4% of a base metal, and its impact energy is also enhance 11.5%.

Keywords

References

  1. B. Gehrmann, U. Heubner, Kolb-Telieps and A.Ed. J. Wittenauer, "The Minearls", Metals and Materials Society, p. 3, 1992.
  2. L.L. Harner, J.J. Stephens and D.R. Frear, "The Minerals", Metals and Materials Society, p. 3, 1992.
  3. C.S. Choi and T. Suzuki, "Study on Deformed Structures of Ni-Co Alloys", J. of the Korean Inst. of Metals, Vol. 21, No.9, pp. 796-801,1993.
  4. Y.B. Park, D. Raabe and T.H. Yim, "Rolling and Recrystallization Textures in Fe-Ni Alloys", J. of the Korean Inst. of Met. & Mater., Vol. 2, No. 3, pp. 151-157, 1996.
  5. K.A. Lee, J.H. Park, B.H. Cho, N.G. Jung and M.C. Kim, "Hot Deformation and Thermal Expansion Behavior of Fe-Ni-Co Low Thermal Expansion Alloy", J. of Inst. Met. & Mater., Vol. 41, No.9, pp. 539-549, 2003.
  6. B.K. Choi, K.C. Jang, B.H. Choi and K.A. Lee, "Influence of Carbon Content on the Mechanical Properties of the Ni-Co Alloy", Transactions of KSMTE, Vol. 15, No.5, pp. 7-13, 2006.
  7. J.H., Lee, H.J. Kim, I.K. Kang, H.S. Kim and H.G. Ahn, J. Lor. Inst. Met & Mater., 31, p. 867, 1993.
  8. M. Hayase, M. Shinga and Y. Nakamura, J. Phys. Soc. Japan, 30,p. 729, 1971 . https://doi.org/10.1143/JPSJ.30.729
  9. Annual Book of ASTM Standards, "Matals Test Methods and Analytical Procedures", Standard Test Methods for Tension of Metallic Materials, E 8M-96, Section 3, pp. 76-96, 1996.
  10. Annual Book of ASTM Standards, "Matals Test Methods and Analytical Procedures", Standard Test Methods for Notched Bar Impact Testing of Metallic Materials, E23-96, Section 3, p. 142, 1996.