Effects of C on the Strength and Toughness of FCAW Weld Metal of YS 460 MPa Steels for Ship and Offshore Structures

선박·해양 구조물용 YS 460MPa 강재 FCAW 용접금속의 강도와 인성에 미치는 C의 영향

  • Received : 2014.10.21
  • Accepted : 2014.11.24
  • Published : 2014.12.31


This paper has an purpose to study the effect of C on the toughness of YS 460 MPa FCAW weld metal. These effects were evaluated by charpy impact and CTOD test about 4 FCAW weld metal containing various C and Si content in relation to microstructure. Increase of C content was helpful to increase AF volume fraction and reduce PF(G) and FS volume fraction by increasing super cooling rate for ferrite transformation. Also, Increase of C content up to 0.045wt% made the strength and impact toughness higher by increasing AF volume fraction. The weld metal containing higher C content indicated higher CTOD value. It is because the volume fraction of PF(G) and FS, can play a role as crack initiation site, was reduced. Effect of C on the strength and elongation of weld metal was higher with an increase of Si contents.


FCAW weld metal;C;Impact toughness;CTOD;Tensile properties


  1. M. Toyoda, N. Kiji, Y. Nakajima, T. Okada, Y. Nakanishi and K. Inose : Safety of Mega Container Ship Focusing on Brittle Crack Initiation and Arrest Behavior of Heavy Thickness Plate, Proceeding of OMAE 2008
  2. Yajima Hiroshi : Lessons to Learn from Damage Examples of Welded Structures and Importance of Basic Technology, Journal of The Japan Welding Society, 81-3 (2012), 151-153 (in Japanese)
  3. Fabrication and Testing of Offshore Structure, DNV-OS- C401 (2010)
  4. Design of Offshore Steel Structures, General, DNV-OS- C101 (2011)
  5. O. M. Akselsen, J. K. Solberg, O. Grong : Effects of martensite-austenite(M-A) islands on intercritical heat-affected zone toughness of low carbon microalloyed steels, Scandinavian journal of metallurgy, 17-5 (1988), 194-200
  6. Y. K. Lee, J. N. Moon, S. H. Kim and C. H. Lee : Correlation Between M-A Constituents and Tensile Properties in the Intercritical Coarse Grained HAZ of an Ultra Low Carbon Steel, KWJS, 28-3 (2010), 99-103 (in Korean)
  7. C. W. Yang, C. S. Kang, S. H. Hwang and K. I. Kim : The Effect of Silicon and Manganese on Mechanical Properties of Modelling Flux Cored Arc Welded Deposit, KWJS, 8-2 (1990), 27-38 (in Korean)
  8. Y. T. Shin, S. W. Kang and M. H. Kim : Evaluation of Fracture Toughness and Microstructure on FCA Weldment According to Heat Input, KWJS, 26-3 (2008), 51-60 (in Korean)
  9. K. S. Bang : Effects of Manganese and Carbon on the HAZ Microstructural Evolution in Titanium Oxide Steel, KWJS, 22-2 (2004), 78-84 (in Korean)
  10. S. W. Kang, M. H. Kim, Y. T. Shin and H. W. Lee : The Effect of Heat Input on Fracture Toughness in Submerged Arc Offshore Steel Weldments, Journal of the Society of Naval Architects of Korea, 41-6 (2004), 40-47
  11. D. J. Abson and R. J. Pargeter : Factors Influencing As-deposited Strength, Microstructure and Toughness of Manual Metal and Arc welds Suitable for C-Mn Steel Fabrications, International Metal Reviews, 31 (1986), 141-194
  12. R. A. Farrar and P. L. Harrison : Acicular Ferrite in Carbon Manganese Weld Metals: An overview, Journal of Materials Science, 22-11(1987), 3812-3820
  13. M. G. Dawes : Fracture Control in High Yield Strength Weldments, Welding Research Supplement, 53 (1974), 369-378
  14. H. J. Kim and B. Y. Kang : Microstructural Characteristics of Steel Weld metal, KWJS, 18-5 (2000), 25-32 (in Korean)