Effect of Hot Isostatic Pressing on Elimination of Internal Defects in IN738LC Superalloy for Gas Turbine Blade

HIP 처리에 의한 가스터빈 블레이드용 IN738LC 초합금의 내부결함 소멸 효과

  • 박영규 (충남대학교 재료공학과) ;
  • 김수형 (한전 전력연구원 발전연구실) ;
  • 김재철 (한전 전력연구원 발전연구실) ;
  • 이영찬 (한전 전력연구원 발전연구실) ;
  • 김두수 (한전 전력연구원 발전연구실) ;
  • 최철 (한전 전력연구원 발전연구실) ;
  • 김길무 (충남대학교 재료공학과)
  • Published : 1999.10.20

Abstract

Most investment castings contain some porosities and microcavities. In this study, we investigated the elimination trends of various internal defects in IN738LC investment castings for industrial gas turbine blade by hot isostatic pressing. The results showed that cylindrical defects which are under $0.6mm{\Phi}{\times}7mm$ size are mostly eliminated and aspect ratio of defects is more sensitive factor than their cross section shape in removing these defects. Increasing hot isostatic pressure and holding time doesn't affect the elimination trend of cylindrical defects over $0.6mm{\Phi}{\times}7mm$ size because first step(plastic deformation) of HIP densification doesn't occur under these HIPping conditions.

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