Abstract

In hot closed-die forging the load increases rapidly near the final stage. Preforming operation is important to both the sound final forging and die-service life. In this study, the material flows during preforming and final forging are investigated. The physical modeling with Plasticine as a model material showed clear flow patterns. The forging process were numerically simulated by the finite element method with the isothermal and the non-isothermal models. The flow patten of the isothermal simulation showed good agreements with the experiments. Temperature changes and pressure distributions on the die surfaces during one cycle of the forging process were obtained from the non-isothermal simulation. High pressure and temperature were developed at certain areas of the die surfaces. It was concluded that those areas usually coincide with each other and should be distributed by the preforming operations to enhance the die life.

Keywords

• Closed-Die Forging;
• Thermo-Viscoplastic Finite Element Method;
• Preform;
• Finisher Die;
• Physical Modeling;
• Die Wear

• 형단조;
• 열-점소성 유한요소법;
• 예비성형체;
• 최종 성형금형;
• 모델재료실험;
• 금형마멸;