Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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Stress Distribution around Laser-Welded Cutting Wheels Using a Spherical Indentation

구형압입을 이용한 레이저 용접된 절단 휠의 잔류응력 분포 측정

  • Lee, Yun-Hee (Division of Quality of Life, Korea Research Institute of Standards and Science) ;
  • Lee, Wan-Kyu (Division of Quality of Life, Korea Research Institute of Standards and Science) ;
  • Jeong, In-Hyeon (Division of Quality of Life, Korea Research Institute of Standards and Science) ;
  • Nahm, Seung-Hoon (Division of Quality of Life, Korea Research Institute of Standards and Science)
  • 이윤희 (한국표준과학연구원 삶의질표준본부) ;
  • 이완규 (한국표준과학연구원 삶의질표준본부) ;
  • 정인현 (한국표준과학연구원 삶의질표준본부) ;
  • 남승훈 (한국표준과학연구원 삶의질표준본부)
  • Published : 2008.04.30
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Abstract

A spherical indentation has been proposed as a nondestructive method of measuring local residual stress field in laser-voided joints. The apparent yield strengths interpreted from the spherical indentation data of as-welded cutting wheel were compared with the intrinsic yield strengths measured at nearly equivalent locations in annealed wheel. Their difference along the distance from the welding line is welding stress distribution because the intrinsic yield strength is invariant regardless of the elastic residual stress. The spherical indentations show that the laser-welded diamond cutting wheel displays a 10 min-wide distribution of the welding residual stress and has peak compressive and tensile stresses in the shank and tip regions, respectively.

레이저 용접부의 국소 잔류응력을 측정하기 위한 비파괴 기법으로 구형압입시험이 제안되었다. 용접상태 절단휠의 구형압입시험으로 얻어진 겉보기 항복강도와 절단횔 용접부에 대한 응력완화 열처리 이후 동등한 위치에서 구한 고유 항복강도를 정량적으로 비교하였다. 고유항복강도가 탄성한도 내의 잔류응력에 의해서 변화하지 않는다고 고려하면 용융선으로부터 거리에 따른 두 항복강도의 차이가 용접잔류응력의 분포로 나타난다. 레이저 용접된 다이아몬드 절단휠의 구형압입시험으로부터 약 10 mm 폭에 걸친 잔류응력의 분포를 확인하였으며, 잔류응력은 쌩크와 절단팁 내에서 각각 최대 압축 및 인장 잔류응력치를 나타내었다.

Keywords

References

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