A Study on the Fracture Toughness Characteristics of FCAW Weldment of Steel for Offshore Structures

해양 구조물용 강재 FCAW 용접부의 파괴인성 특성에 관한 연구

  • Kang Sung-Won (Dept. of Naval Architecture & Ocean Engineering, Pusan National University) ;
  • Kim Myung-Hyun (Dept. of Naval Architecture & Ocean Engineering, Pusan National University) ;
  • Kim Yong-Bin (Dept. of Naval Architecture & Ocean Engineering, Pusan National University) ;
  • Shin Yong-Taek (Institute of Industrial Technology, Samsung Heavy Industries) ;
  • Lee Hae-Woo (Institute of Industrial Technology, Samsung Heavy Industries)
  • 강성원 (부산대학교 조선해양공학과) ;
  • 김명현 (부산대학교 조선해양공학과) ;
  • 김용빈 (부산대학교 조선해양공학과) ;
  • 신용택 (삼성중공업 생산기술연구소) ;
  • 이해우 (삼성중공업 생산기술연구소)
  • Published : 2004.12.01

Abstract

Fracture toughness is an important parameter in designing offshore structures to ensure resistance to fracture at various temperatures. In this study, a series of experiments is carried out to obtain fracture toughness values (CTOD) of API 2W Gr.50B, welded using FCAW(Flux Cored Arc Weld). In particular, a comparison of absorbed impact energy and CTOD values are made with respect to two different welding groove shapes; double-V-groove and double-bevel-groove. Charpy impact tests are performed for specimens sampled near the root gap, and CTOD tests are carried out for three point bending specimens having the notch at weld zone. While Charpy impact test result is determined to be a good qualitative measure of fracture toughness, no quantitative correspondence between impact absorbed energy and CTOD values was found. Based on the experiment, it is observed that double-V-groove welds give lower transition temperature than those of double-bevel-groove.

Keywords

References

  1. H. W. Lee, Y. T. Shin, J. U. Park and H. G. Suk :A Study on Metallurgical Properties and Fatigue Strength depending on Bead Height in SAW Butt Joints, Journal of the Society of Naval Architects of Korea, 35-3 (1998) , 62-70 (in Korean)
  2. H. H. Jung, C. M. Kim, H. S. Kim, W. S. Kim, and S. H. Hong Effect of Heterogeneous Microstructure on the fracture Toughness of Weld Metal, Journal of the Korean Welding Society, 17-2 (1999) , 98-105(in Korean)
  3. G. M. Evans : The Effect of Nickel on Microstructure and Properties of C-Mn all Weld Metal Deposits,Welding Research Abroad, 37-2/3 (1991), 70-73
  4. Z. Zhang & R. A. Farrar : Influence of Mn and Ni on the Microstructure and Toughness of C-Mn-Ni Weld Metals, Welding Journal, 76-5 (1997), 183s-190s
  5. A. C Hunt, A. O. Kuken and G. R. Edwards : Heat Input and Dilution Effects in Microalloyed Steel Weld Metals, Welding Journal, January (1994),9a-14s
  6. B. C. Kim, S. Lee, N. J. Kim, D. Y. Lee : Microstructure and Local Brittle Zone Phenomena in HSLA Steel Welds, Metallurgical Transaction A. 22a (1991),139-149
  7. Gennadiv P. Nikishkov. Jurgen Heerens and Dieter Hellmann : Effect of Crack Front Curvature and Side Grooving on CTOD $\delta$5 and J-Intergral in CT and 3PB Specimen, Journal of Testing and Evaluation, 17-5 (1999), 312-319