• 제목/요약/키워드: weld strength

검색결과 857건 처리시간 0.028초

자동차 부품용 강재(SM40C)의 마찰용접 최적화와 AE에 의한 실시간 품질평가에 관한 연구 (A Study on Optimization of Friction Welding of Automobile Component Materials(SM40C) and Its Real Time Quality Evaluation by AE)

  • 오세규;박종배;공유식
    • 한국해양공학회지
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    • 제13권1호통권31호
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    • pp.88-93
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    • 1999
  • This paper presents the experimental examinations and statistical quantitative analysis of the correlation between the cumulative counts of acoustic emission(AE) during plastic deformation periods of the welding and the tensile strength and other properties of the bar-to-bar welded joints of O.D. 16mm shaft(SM40C) as well as the various welding variables. And this is a new approach which attempts finally to develop real-time quality monitoring system for friction welding. The results lead to a practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro structural defects.

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극저탄소 냉연강판의 Mash Seam TB를 이용한 용접 시 특성과 평가에 관한 연구 (A study on characteristics and evaluation of Mash Seam TB weld in ultra-low carbon steel applied on automotive body)

  • Han, Chang-Woo;Lee, Chang-Hee
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2001년도 추계학술발표대회 개요집
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    • pp.81-84
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    • 2001
  • This study introduces the new way for the evaluation criteria of the Mash-Seam Tailored Blank weldability, The materials used are low carbon automotive galvanized and high strength steels and the evaluation of weldability are examined with various thickness. Welding tests were conducted for both similar thickness and dissimilar thickness cases. The criteria developed for optimum welding conditions were based on the relationship among results of die press forming test, forming limit diagram, Erichsen test and microhardness measurements. The application of the developed criteria(fracture ratio, strength ratio, etc) in obtaining optimum welding condition revealed that a weld which satisfied ant of the criteria did not fracture during actual die press test and FLD dome test.

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원전 역지 밸브/배관 맞대기 용접부와 밸브 몸체의 취성 파괴에 미치는 잔류응력 및 Charpy V-노치 충격에너지의 영향 고찰 (Investigation on Effects of Residual Stresses and Charpy V-Notch Impact Energy on Brittle Fractures of the Butt Weld between Close Check Valve and Piping, and of the Valve Body in Nuclear Power Plants)

  • 김종성;김현수
    • 한국압력기기공학회 논문집
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    • 제11권1호
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    • pp.69-73
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    • 2015
  • The study investigated effects of residual stresses and Charpy impact energy on brittle fractures of the butt weld between the valve and the piping, and of the valve body in nuclear power plants via a linear elastic fracture mechanics approach in the ASME B&PV Code, Sec.XI and finite element analysis. Weld residual stress in a butt weld between close check valve and piping, and residual stress in the valve due to casting process were assumed to be proportional to yield strength of base metal. Operating stresses in the butt weld and the valve body were calculated using approximate engineering formulae and finite element analysis, respectively. Applied stress intensity factors were calculated by assuming postulated cracks with specific sizes and then by substituting the residual stresses and the operating stresses into engineering formulae presented in the ASME B&PV Code, Sec.III. Plane strain fracture toughness was derived by using a correlation between Charpy V-notch impact energy and fracture toughness. Structural integrity of the weld and the body against brittle fracture was assessed by using the applied stress intensity factors, plane strain fracture toughness and the linear elastic fracture mechanics approach. As a result, it was identified that the structural integrity was maintained with decreasing the residual stress levels and increasing the Charpy V-notch impact energy.