FE analysis of coupled thermo-mechanical behaviors in radial-axial rolling of alloy steel large ring

Radial-axial rolling of alloy steel large ring (ASLR) is an advanced plastic forming process with complex coupled thermo-mechanical deformation behaviors which have significant influences on the microstructure and properties of the product. In this paper, the stable forming conditions and ranges of key forming parameters for the radial-axial rolling process of ASLR are determined reasonably. Then a 3D elastic-plastic and coupled thermo-mechanical FE model of radial-axial ring rolling is explored using the dynamic explicit code ABAQUS/Explicit, and its reliability is verified theoretically and experimentally. Using FE simulation and analysis, the effects of key forming parameters on the uniformity of deformation and temperature distribution of ASLR are investigated. The main results show that: (1) The deformation and temperature distribution of the ASLR are nonuniform in radial-axial ring rolling. The PEEQ gradually decreases from the surface region to the central region of the ASLR while the temperature distribution is reverse. The largest PEEQ and smallest temperature appear in the edge region of the ASLR. (2) With increasing the feed speeds of rolls, initial temperature of blank or decreasing the rotation speeds of rolls, the deformation of the ASLR becomes more uniform. (3) With increasing the feed speeds of rolls, rotation speeds of rolls or decreasing the initial temperature of blank, the temperature distribution of the ASLR becomes more homogeneous. (4) The friction coefficient has a slight effect on the uniformity of deformation and temperature distribution of the ASLR. The results provide an important basis for improving the microstructure and forming quality of ASLR through optimization of forming parameters.