International Journal of Naval Architecture and Ocean Engineering

  • 제6권4호
  • /
  • Pages.922-934
  • /
  • 2014
  • /
  • 2092-6782(pISSN)
  • /
  • 2092-6790(eISSN)
대한조선학회 (The Society of Naval Architects of Korea)
권호 표지
DOI QR코드

DOI QR Code

Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

  • Lim, Sang-Sub (Precision Manufacturing System Division, Pusan National University) ;
  • Mun, Jae-Chul (Precision Manufacturing System Division, Pusan National University) ;
  • Kim, Tae-Won (Sekjin Metal Co., Ltd.) ;
  • Kang, Chung-Gil (School of Mechanical Engineering, Pusan National University)
  • 발행 : 2014.12.31
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

키워드

과제정보

연구 과제 주관 기관 : National Research Foundation of Korea (NRF)

참고문헌

  1. Bethlehem Steel Corporation, 1972. Modern steels and their properties. 7th ed. Bethlehem, PA: Bethlehem Steel Corporation.
  2. Hall, E.O., 1951. Deformation and ageing of mild steel: III Discussion of results. Proceeding Physical Society (London), B64(9), pp.747-753.
  3. Horn, R.M. and Ritchie, R.O., 1978. Mechanisms of tempered martensite embrittlement in low alloy steels. Metallurgical Transactions A, 9(8), pp.1039-1053. https://doi.org/10.1007/BF02652208
  4. Kim, T.W., Lim, S.S., Seok, H.H. and Kang, C.G., 2013. Concurrent engineering solution for the design of ship and offshore bracket parts and fabrication process. International Journal of Naval Architecture and Ocean Engineering, 5(3), pp.376-391. https://doi.org/10.3744/JNAOE.2013.5.3.376
  5. Krauss, G. and Marder, A.R., 1971. The morphology of martensite in iron alloys. Metallurgical Transactions, 2(9), pp. 2343-2357. https://doi.org/10.1007/BF02814873
  6. Petch, N.J., 1953. The cleavage strength of polycrystals. The Journal of the Iron and Steel Institute, 174(5), pp.25-28.
  7. Pickering, F.B., 1978. Physical metallurgy and the design of steels. London: Applied Science Publishers Ltd.
  8. Sinha, A.K., 1989. Ferrous physical metallurgy. Butterworth & Co., Ltd, Boston, USA.
  9. Suh, J.H., Kim, S.H., Park, J.Y., Cho, S.H., Choi, J.G. and Kim, M.H., 2006. Visualization and interaction for simulation of casting solidification. Proceedings of the Korea Society for Simulation 2006 Autumn Conference, pp.3-7.
  10. Tamura, I., Sekine, H., Tanaka, T. and Ouchi, C., 1988. Thermomechanical processing of high strength low alloy steels. London: Butterworth & Co. Ltd.
  11. Tsukada, K., Matsumoto, K., Hirabe, K. and Takeshige, K., 1982. Application of on-line accelerated cooling (OLAC) to steel plate. Iron Steelmaker 9, 7, pp.21-28.
  12. Union Carbide Corporation. Metals Division., 1975. Microalloying 75. New York: ASM International.