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The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (I) - Laser Weldability of Al-Si Coated Boron Steel Used for Hot Stamping Process -

레이저 열원을 이용한 보론강 및 핫스탬핑강의 용접특성에 관한 연구 (I) - 핫스탬핑 공정에 사용되는 Al-Si 코팅된 보론강의 레이저 용접특성 -

  • Kim, Jong Do (Division of Marine Engineering, Korea Maritime and Ocean Univ.) ;
  • Choi, So Young (Division of Marine Engineering, Korea Maritime and Ocean Univ.) ;
  • Lee, Su Jin (Joining and Welding Research Institute, Osaka Univ.) ;
  • Suh, Jeong (Busan Laser Application Support Center, Korea Institute of Machinery & Materials)
  • 김종도 (한국해양대학교 기관공학부) ;
  • 최소영 (한국해양대학교 기관공학부) ;
  • 이수진 (오사카대학교 접합 연구소) ;
  • 서정 (한국기계연구원 부산레이저기술지원센터)
  • Received : 2014.09.29
  • Accepted : 2014.11.03
  • Published : 2014.12.01

Abstract

As the awareness of the environmental crisis has recently increased around the world, numerous studies in the transport industry have been conducted to solve this problem through lightweight car bodies. The hot-stamping process has been presented as solution to achieve a light weight. Hot-stamping is a method that is used to obtain ultra-high strength steel (1,500 MPa or greater) by simultaneously forming and cooling boron steel in a press die after heating it to a temperature of $900^{\circ}C$ or above. This study involved a, fundamental examination of laser parameters to investigate the laser weldability of boron steel. As a result, the following optimum parameters for the shielding gas were found: Q = 20 l/min, ${\alpha}=40^{\circ}$, d = 20mm, and l = 0 mm. The hardness of butt weldment increasesed sharply as a result of martensite formation at the fusion zone.

Keywords

Hot Stamping;Al-Si Coated Boron Steel;Laser Welding Parameter

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