# FCAW 이종접합에서 용접자세에 따른 기계적 시험 특성 평가

• Cho, Byung-Jun (Korea Polytechnic University New Technology Education Center) ;
• Lee, Soung-Jun (Siheung Facilities Management Corporation)
• 조병준 (한국폴리텍대학 신기술교육원) ;
• 이성준 (시흥시시설관리공단)
• Accepted : 2019.08.02
• Published : 2019.08.31

#### Abstract

Flux cored arc welding (FCAW), which is used widely in many fields, such as shipyards, bridge structures, construction machinery, and plant industry, is an alternative to shielded metal arc welding (SMAW). FCAW is used largely in the welding of carbon and alloy steel because it can be welded in all poses and obtain excellent quality in the field under a range of working conditions. In this study, the mechanical properties of welded parts were analyzed after different welding of SS400 and SM490A using FCAW. The following conclusions were drawn. The tensile test results satisfied the KS standard tensile strength in the range of 400~510 N/mm2 in all welding positions. The bending test confirmed that most of the specimens did not show surface breakage or other defects during bending and exhibited sufficient toughness, even after plastic deformation. The hardness test results were lower than the standard value of 350 Hv of KS B 0893. Similar to the hardness test, were greater than the KS reference value. The macro test revealed no internal flaws, non-metallic inclusions, bubbles or impurities on the entire cross section of the weld, and there were no concerns regarding lamination.

#### References

1. J. H. Koh, J. H. Kook, "A Study on the Effect of Heat Input on the Microstructure and Toughness of Weldments Made by Domestic Flux Cored Wires", Journal of the Korean Welding society, Vol.11, No.4, pp.57-69, 1993.
2. C. J. Ahn, "A Study on Mechanical Properties and Weldability Characteristics of Rolled (SHN400) H-Shape Section Steel", Master's thesis, Soongsil University Graduate School, pp.1-4.
3. B. H. Kim, W. I. Kim, C. Choi, Y. H. Park, "Study of Weld Part Status Change by $CO_{2}$ Welding According to the Variation of Gas Composition and Welding Wire on SS400 Material", Journal of the Korean Society of Manufacturing Process Engineers, Vol. 11, No. 5, pp. 129-136, 2012.
4. B. C. Goo, "Fatigue of SS490A and SS400 Corroded Specimens", Journal of Korean Railway Association, Vol. 12, No. 5, pp. 725-731, 2009.
5. S. B. Kim, C. N. Lee, J. G. Yang, S. S. Kim, "Study on the Welding Characteristics of High Strength(500MPa) Reinforcing Bar According to Tensile Test", Journal of Architectural Institute of Korea Structural System, Vol. 27, No. 1, pp. 59-67, 2011.
6. D. H. Kim, D. Y. Kim, K. T. Lee, H. Y. Kim, "Strength Analysis of MIG Welding Specimen Considering Weld Characteristics", Conference on the Sector of the Korean Society of Automotive Engineers, Ilsan, Korea, pp. 1195-1201, 2012. 5.
7. J. Y. Kim, S. S. Kang, G. Y. Kim, S. C. Park, C. K. Kim, "Research on Fafigue Life Prediction of Muffler with Weld-zone Shape", Journal of the Korean Society of Marine Engineering, Vol. 36, No. 1, pp. 85-93, 2012. DOI: http://dx.doi.org/10.5916/jkosme.2012.36.1.85 https://doi.org/10.5916/jkosme.2012.36.1.85