업셋 단조의 좌굴 및 소성 불안정 유동에 관한 연구

A Study on the Buckling and Plastic Instable Flow in Upset Forging

  • 김완수 (충남대학교 대학원 기계공학과) ;
  • 이병섭 (충남대학교 대학원 기계공학과) ;
  • 황두순 (충남대학교 기계공학과) ;
  • 홍성인 (충남대학교 기계공학과)
  • 발행 : 1999.08.01

초록

The plastic instable flow phenomenon happens in practical forming process, I. e. upsetting, backward extrusion, piercing, indentation. And also, it is difficult to control precisely the shape and dimensions of forming process. It is found that instabilities of the process are mainly connected with imperfections in the lubrication, billet eccentricity, inclined punch alignment. In view of the direct relationship between instable material flow and quality defects of the products and for better control of forming operation, we should necessarily find out their phenomena. In this study, we introduced the friction disturbance due to inclined punch angle. Analysis of upset forging is carried out using the rigid plastic FEM and slab method with eccentricity. Also, we considered the buckling parameters of billet with the large aspect ratio in upset forging.

키워드

참고문헌

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