Journal of Welding and Joining

The Korean Welding and Joining Society (대한용접접합학회)
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Evaluation of Resistance Spot Weld Interfacial Fractures in Tensile-Shear Tests of TRIP 1180 Steels

인장전단시험을 이용한 TRIP1180강의 계면파단특성 평가

  • Park, Sang-Soon (Dept. of Advanced Material Engineering, Dong-eui University) ;
  • Choi, Young-Min (Automotive Steel Products Research Group, Technical Research Labs., POSCO) ;
  • Nam, Dae-Geun (Division for Dongnam Area Technology Service, Korea Institute of Industrial Technology) ;
  • Kim, Young-Seok (Division for Dongnam Area Technology Service, Korea Institute of Industrial Technology) ;
  • Yu, Ji-Hun (Dept. of Powder Materials Research, Korea Institute of Materials Science) ;
  • Park, Yeong-Do (Dept. of Advanced Material Engineering, Dong-eui University)
  • 박상순 (동의대학교 신소재공학과) ;
  • 최영민 (POSCO 기술연구소 자동차소재연구그룹) ;
  • 남대근 (한국생산기술연구원 동남권 기술지원본부) ;
  • 김영석 (한국생산기술연구원 동남권 기술지원본부) ;
  • 유지훈 (한국기계연구원 부설 재료연구소) ;
  • 박영도 (동의대학교 신소재공학과)
  • Published : 2008.12.31
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Abstract

The weldability of resistance spot welding of TRIP1180 steels for automobile components investigated enhance in order to achieve understanding of weld fracture during tensile-shear strength (TSS) test. The main failure modes for spot welds of TRIP1180 steels were nugget pullout and interfacial fracture. The peak load to cause a weld interfacial failure was found to be related to fracture toughness of the weld and the weld diameter. Although interfacial fracture occurred in the spot welded samples, the load-carrying capacity of the weld was high and not significantly affected by the fracture mode. Substantial part of the weld exhibits the characteristic dimple (or elongated dimple) fractures on interfacial fractured surface also, dimple fracture areas were drawmatically increased with heat input which is propotional to the applied weld current. In spite of the high hardness values associated with the martensite microstructures due to high cooling rate. The high load-carrying ability of the weld is directly associated with the area of ductile fracture occurred in weld. Therefore, the judgment of the quality of resistance spot welds in TRIP1180 steels, the load-carrying capacity of the weld should be considered as an important factor than fracture mode.

Keywords

References

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