Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
권호 표지
DOI QR코드

DOI QR Code

A study on the optimization of manufacturing processes of double wall bellows for dual fuel engine II - Optimization of welding process -

Dual Fuel 엔진용 이중관 벨로우즈 제작 공정의 최적화에 관한 연구 II - 용접공정의 최적화 -

  • Kim, Pyung-Su (Hanjo Co., Ltd, Engineering Center) ;
  • Kim, Jong-Do (Division of Marine Engineering, Korea Maritime and Ocean University) ;
  • Song, Moo-Keun (Graduate school, Korea Maritime and Ocean University)
  • Received : 2016.04.14
  • Accepted : 2016.06.21
  • Published : 2016.07.31
Download PDF
⟨ Previous Next ⟩

Abstract

Production processes of double wall bellows can be roughly categorized into two steps. In the first step, inner and outer bellows are made of STS316L in austenite stainless steel due to their excellent formability and corrosion resistance. In the second step, the double wall bellows are manufactured using the welding method with both the inner and outer bellows. The microstructure and defects of each weldment are observed to ensure the reliability of bellows since weldment is a highly vulnerable part, which can crack and fracture when bellows are formed or used. In this study, optimum welding conditions were derived from the analysis of microstructure and inspection of weldment of bellows that were produced using various welding procedure. Moreover, the mechanical properties were evaluated through hardness measurement of substrate, weldment and the heat-affected zone.

이중관 벨로우즈는 우수한 성형성과 내식성을 고려하여 오스테나이트계 스테인리스강인 STS 316L 소재를 사용하여 2겹으로 내부 및 외부 벨로우즈를 각각 제작한 후 다양한 조건과 용접 방법을 적용하여 이중관 벨로우즈를 제작한다. 하지만 제품의 성형 또는 사용시 균열이나 파단에 가장 취약한 부분이 용접부이기 때문에 제품의 신뢰성을 획득하기 위하여 각각의 용접부에 대한 미세조직을 관찰하여 결함 발생 여부를 측정해야 한다. 본 연구에서는 다양한 용접 공정을 거쳐 제작된 벨로우즈의 용접부를 검사하고 미세조직을 분석하여 최적의 용접 조건을 도출하였다. 또한 용접부의 경도 측정을 통해 모재와 용접부 그리고 열영향부 등 용접영역의 기계적 특성을 평가하였다.

Keywords

References

  1. P. S. Kim, H. Y. Choi, S. Y. Choi, Y. S. Kim, and J. D. Kim, "Fundamental study on the weldability and formability of INCOLOY 825 alloys and STS316L alloys," Journal of the Korean Society of Marine Engineering, vol. 38, no. 6, pp. 698-703, 2014 (in Korean). https://doi.org/10.5916/jkosme.2014.38.6.698
  2. Y. S. Kim and S. C. Kil, "Latest welding technology for storage and transportation facilities of liquified natural gas," Journal of the Korean Society of Marine Engineering, vol. 40, no. 1, pp. 17-27, 2016 (in Korean). https://doi.org/10.5916/jkosme.2016.40.1.17
  3. J. D. Kim, C. J. Lee, and M. K. Song, "Characteristics of fiber laser welding on STS304L for GTT MARK III membrane," Journal of the Korean Society of Marine Engineering, vol. 36, no. 8, pp. 1069-1075, 2012 (in Korean). https://doi.org/10.5916/jkosme.2012.36.8.1069
  4. Y. H. Moon and S. D. Huh, "The factors to form delta-ferrite in austenitic stainless steel weldment," The Korean Welding&Joining Society, vol. 5, no. 1, pp. 16-22, 1987 (in Korean).
  5. H. W. Lee, Y. T. Shin, J. U. Park, J. W. Lee, and C. Y. Kang, "A study of low temperature strength and fatigue strength of austentic stainless steel for membrane type LNG tank," Journal of Korea Welding Society, vol. 17, no. 3, pp. 50-54, 1999 (in Korean).
  6. E. A. Trillo, R. Beltran, J. G. Maldonado, R. J. Romero, L. E. Murr, W. W. Fisher, and A. H. Advani, "Combined effects of deformation(Strain and strain state), grain size and carbon content on carbide precipitation and corrosion sensitization in 304 stainless steel," Materials Characterization, vol. 35, no. 2, pp. 99-112, 1995. https://doi.org/10.1016/1044-5803(95)00072-0
  7. D. A. Butzea, H. J. Cordewiner, C. Stickelmann, H. P. Muller, and R. Hemminger, Manufacturing and Quality Test of the Metal Bellows of the TEXTOR Vacuum Vessel, Report No. JUEL-SPEZ-229, Zentralabteilung Allgemeine Technologie, Germany, 1983.
  8. A. Laupa and N. A. Weil, "Analysis of U-Shaped Expansion Joint," Journal of Applied Mechanics, vol. 29, no. 1, pp. 115-123, 1962. https://doi.org/10.1115/1.3636442
  9. P. S. Korinko and S. H. Malene, "Considerations for the Weldability of Type 304L and 316L Stainless Steel," Practical Failure Analysis, vol. 1, no. 4, pp. 61-68, 2001. https://doi.org/10.1007/BF02715336
  10. B. S. Rho, H. U. Hong, and S. W. Nam, "The Effect of ${\delta}$-Ferrite on Fatigue Cracks in 304L Steel," International Journal of Fatigue, vol. 22, no. 8, pp. 683-690, 2000. https://doi.org/10.1016/S0142-1123(00)00043-8