Finite Element Analysis of Large Plastic Deformation Process of Pure Molybdenum Plate during Hot Rolling

Abstract

The rare molybdenum resources are being increasingly used in heavy industries. In this study, the common unidirectional and cross hot rolling operations, for pure molybdenum plates, were numerically simulated by using MSC. Marc software. An elastic–plastic finite element model was employed, together with the updated Lagrange method, to predict stress and strain fields in the workpiece. The results showed that there was a typical three-dimensional additional compressive stress (σy> σz > σx) in the deformation zone, while strain could be divided into uniaxial compressive strain and biaxial tensile strain (εy > εx > εz). Tensile stress σx increased with the accumulation of reduction and the decrease in friction coefficient at the edge of the width spread. More importantly, the interlaced deformation caused by cross-commutations, which were helpful in repairing the severe anisotropy created by unidirectional hot rolling. The evolution of the temperature field of pure molybdenum plate was investigated. The surface quenching depth of the pure molybdenum plate was about 1/6 H under different initial temperatures and reductions. In addition, the fundamental reason for the nonuniform distribution of stress and strain fields was the joint influence of rolling stress, contact friction, and external resistance. By comparing the theoretical simulation value of the model with the experimental verification data, we found that the model was aligning well with the actual engineering.

Keywords

• pure molybdenum
• unidirectional hot rolling
• cross hot rolling
• finite element method