Study of void closure in hot radial forging process using 3D nonlinear finite element analysis

Hot radial forging is used to reduce porosity and increase strength for large-diameter billets. The goal of this research is to study void closure behavior in the hot radial forging process. A nonlinear coupled finite element model is developed to investigate the deformation mechanism of internal void defects during the hot radial forging process. The model is formulated in a three-dimensional frame and a viscoplastic material model has been used to describe the material behavior subjected to large deformation and high temperature. A global–local technique is employed to obtain accurate solutions around the void region. The effects of void location, mandrel, die shape, and the reduction of the tube thickness on the final void reduction are systematically investigated. The predicted reductions for central longitudinal voids in hot upsetting and hot rolling processes are in good agreement with experimental findings. The simulation results provide a valuable procedure for the design of porosity reduction during the hot radial forging process.

[1]  Z. Cui,et al.  Theoretical study of void closure in nonlinear plastic materials , 2009 .

[2]  Yong-Taek Im,et al.  Analysis of void closure in open-die forging , 1990 .

[3]  Taylan Altan,et al.  Application of the 2D finite element method to simulation of cold-forging processes , 1992 .

[4]  Mohammad R. Movahhedy,et al.  Die design for the radial forging process using 3D FEM , 2007 .

[5]  Zhenshan Cui,et al.  A criterion for void closure in large ingots during hot forging , 2009 .

[6]  S. H. Kim,et al.  Comparative Study on Pore Closing in Open Die Forging by Conventional Forging Press and Radial Forging Machine , 2010 .

[7]  Joseph P. Domblesky,et al.  Application of the finite-element method to the radial forging of large diameter tubes , 1995 .

[8]  Kang-Yeob Park,et al.  A study for the constitutive equation of carbon steel subjected to large strains, high temperatures and high strain rates , 2002 .

[9]  Y. M. Hwang,et al.  Finite element simulations on void closure behaviour inside the sheet during sheet rolling processes , 2002 .

[10]  Mohammad R. Movahhedy,et al.  A parametric study on residual stresses and forging load in cold radial forging process , 2007 .

[11]  Yongnam Kwon,et al.  Analysis on Void Closure Behavior during Hot Open Die Forging , 2007 .

[12]  Man-Soo Joun,et al.  FINITE ELEMENT SIMULATION OF PORE CLOSING DURING CYLINDER UPSETTING , 2009 .

[13]  J. Chen,et al.  Three-Dimensional Nonlinear Finite Element Analysis of Hot Radial Forging Process for Large Diameter Tubes , 2010 .

[14]  Jianning Tang.  A study of oxide scale deformation and surface roughness transformation in hot strip rolling , 2006 .

[15]  Taylan Altan,et al.  Metal Forming : Fundamentals and Applications , 1983 .

[16]  Dyi-Cheng Chen.  Rigid-plastic finite element analysis of plastic deformation of porous metal sheets containing internal void defects , 2006 .

[17]  James J.H. Liou,et al.  Study of stress development in axi-symmetric products processed by radial forging using a 3-D non-linear finite-element method , 1998 .

[18]  Anders Wallerö,et al.  Closing of a central longitudinal pore in hot rolling , 1985 .