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초음파 감쇠를 이용한 순 티타늄 판재의 용접부 특성

Characteristics of Welds of Pure Titanium Plate Using Ultrasonic Attenuation

  • 선상원 (숭실대학교 기계공학과) ;
  • 이원 (숭실대학교 기계공학과) ;
  • 박희동 (한국건설생활환경시험연구원) ;
  • 황영탁 (강원대학교 메카트로닉스공학과)
  • 투고 : 2013.02.20
  • 심사 : 2013.04.18
  • 발행 : 2013.04.30

초록

초음파 감쇠를 이용하여 티타늄 용접부에 대해 기계적 특성, 파단면 및 초음파특성을 연구하였다. 준비된 티타늄 시험편은 아르곤 가스를 이용하여 제작하였다. 티타늄 용접 시험편이 파단 되었을 때 변화하는 초음파 신호변화를 확인하기 위해서 인장시험을 실시하였다. 주사전자현미경을 이용하여 파단면을 관찰하고, 4 MHz 수직 탐촉자를 이용하여 초음파 시계열 신호를 획득하였다. 티타늄 판재에서 용접부는 모재부와 열영향부에 비하여 기계적 특성이 떨어지며 파단면분석을 통해 용접부의 입자크기가 모재부보다 큼을 확인할 수 있었다. RMS 신호 처리한 초음파 포락선의 면적과 인장강도의 상관관계를 나타내었다. 따라서 초음파를 이용하여 티타늄 용접부의 건전성 평가 방법이 유용함을 알 수 있었다.

This paper studies on mechanical properties, fractures, and ultrasonic characteristics of Pure Titanium welds using ultrasonic attenuation. Ti specimen was made by using AR purge gas. When the titanium weld specimen is fractured, Tensile tests were conducted in order to observe the ultrasonic signal changes. A scanning electron microscope(SEM) was used to observe changes in failure surface and an ultrasonic normal probe with the central frequency of 4 MHz was used to obtain ultrasonic signals. As a result, the value of the mechanical properties in the weld zone was lower than that in the base zone and heat affected zone(HAZ) from Ti. Also the grain size in the weld zone was bigger than that in the weld zone and HAZ from Ti. Ultrasonic signals using a RMS method presents correlation between envelope area and the tensile strength. Consequently, the ultrasonic method could be potential tool for integrity evaluation of the Ti weld zone.

키워드

참고문헌

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피인용 문헌

  1. Very High Cycle Fatigue of Butt-Welded High-Strength Steel Plate vol.7, pp.3, 2017, https://doi.org/10.3390/met7030103