Determination of strain field and heterogeneity in radial forging of tube using finite element method and microhardness test

Utilizing the Finite Element Method (FEM), the strain field in the radial forging process of tube is calculated at different process conditions and compared with the experimental results achieved using the microhardness test. The effect of various process parameters such as friction, axial feed, back push and front pull forces and die angles on the strain field are investigated. Using the results of the analysis, it is shown that the deformation inhomogeneity, introduced by an Inhomogeneity Factor (IF), is maximum in the inner zone of tube, while the minimum and the maximum effective strains are appeared at the inner zone of tube and about the core of the tube thickness, respectively. Also, it was found that inhomogeneity decreases by increasing the die angle, decreasing the back push force and decreasing the friction factor.

► Direct comparison of local values of strain is obtained from simulation. ► Derivation of the relationship between the hardness and strain. ► Calculation of the strain field and comparison with the predicted values by the FEM analysis. ► The inhomogeneity factor at the inner diameter and outer of tube was investigated.