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The effect of Heat input and PWHT on the microstructure and mechanical properties of HSB600 steel weldments

HSB600강 GMA 용접부에서 입열량과 용접후 열처리가 미세조직과 기계적 특성에 미치는 영향

  • Koh, Jin-Hyun (School of Energy.Materials.Chemical, Korea University of Technology and Education) ;
  • Kim, Nam-Hoon (School of Energy.Materials.Chemical, Korea University of Technology and Education) ;
  • Jang, Bok-Su (School of Energy.Materials.Chemical, Korea University of Technology and Education) ;
  • Ju, Dong-Hwi (School of Energy.Materials.Chemical, Korea University of Technology and Education) ;
  • Lim, Young-Min (School of Energy.Materials.Chemical, Korea University of Technology and Education)
  • 고진현 (한국기술교육대학교 에너지.신소재.화학공학부) ;
  • 김남훈 (한국기술교육대학교 에너지.신소재.화학공학부) ;
  • 장복수 (한국기술교육대학교 에너지.신소재.화학공학부) ;
  • 주동휘 (한국기술교육대학교 에너지.신소재.화학공학부) ;
  • 임영민 (한국기술교육대학교 에너지.신소재.화학공학부)
  • Received : 2011.09.20
  • Accepted : 2011.12.13
  • Published : 2011.12.31

Abstract

The effects of heat input (1.5~3.6 kJ/mm) and post weld heat treatment (PWHT, $600^{\circ}C$, 40hr.) on the TMCP HSB600 steel weldments made by GMAW process were investigated. The tensile strengths and hardness of as-welded specimens were decreased as heat input increased, but CVN (Charpy V-Notch) impact energy did not show any differences. The fine-grained acicular ferrite was mainly formed in the low heat input while polygonal and side plate ferrites were dominated in the high heat inputs. Meanwhile, tensile strength and hardness of PWHT weldments were decreased due to the coarsening and globular of microstructure as well as reduction of residual stresses.

Keywords

HSB600 steel;GMA Welding;Welding process;Weldability;Mechanical property

Acknowledgement

Supported by : 중소기업청

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