Optimal Die Design for Uniform Microstructure in Hot Extruded Product

열간압출품의 미세조직 균일화를 위한 최적 금형설계

  • Published : 1999.10.01

Abstract

The properties of deformed products are generally dependent upon the distribution of microstureture. It is, therefore, necessary to make the distribution of microstureture uniform in order to achieve the best balance of properties in the final product. This is often a demanding task, even for conventional materials. It is become essential to achieving mechanical integrity and a desired combination of microstructure and properties. The objective mechanical integrity and a desired combination of microsttucture and properties. The objective of this study is to design the optimal die profile which can yield more uniform microstructure in hot extruded product. The microstructure evolution, such as dynamic and static recrystallization as well as grain growth, is investigated using the program com-bined with yada and Senuma's empirical equations and rigid-thermoviscoplastic finite element method. The die profile of hot extrusion is represented by Bezier-curve to define all available profile. In order to obtain the optimal die profile which yields uniform microstructure in the product the FPS(Flexible Polyhedron Search) method is applied to the present study. To validate the result of present study the experimental hot extrusion is performed and the result is compared with that of simulation.

Keywords

References

  1. Metal Science v.13 Recrystallization and grain growth in hot rolling C.M.Sellars;J.A.Whiteman
  2. J. JSTP v.27 Resistance to hot deformation of steel H.Yada;T.Senuma
  3. 한국소성가공학회지 v.7 열간단조공정중 강의 재결정거동 유한요소해석 곽우진;이경종;권오준;황상무
  4. 한국정밀공학회지 v.15 유한요소법에 의한 열간성형공정에서 강의 미세조직변화 예측 장용순;고대철;김병민
  5. J. Mater. Process. Technol. v.45 Multistage compression of mecroalloyed steels-FE simulation and measurements of grain size M.Pietrzyk;Z.Kedzierski;J.G.Lenard;M.Tajima;J.Majta
  6. J. Mater. Process. Technol. v.43 Numerical simulation of the microstructure in the ring rolling of hot steel S.G.Xu;Q.X.Cao
  7. 한국소성가공학회 '95 추계학술대회 논문집 열간압연중 발생하는 미세조직 변화에 관한 연구 조현중;김낙수
  8. JMEPEG v.2 no.5 An innovative strategy for open loop control of hot deformation processes J.C.Malas;R.D.Irwin;R.V.Grandhi
  9. Int. J. Num. Meth. Eng. v.37 Design of optimal process parameters for nonisothermal forging H.Cheng;R.V.Grandhi;J.C.Malas
  10. Metal forming and the finite element method S.Kobayashi;S.I.Oh;T.Altan
  11. Applied nonlinear programming D.M.Himmelblau
  12. Computer graphics and geometric modeling for engineers V.B.Anand
  13. J. JSTP v.10 Empirical formula of flow stress of carbon steel-resistance to deformation of carbon steels at elevated temperature S.Shida