3D coupled thermo-mechanical FE modeling of blank size effects on the uniformity of strain and temperature distributions during hot rolling of titanium alloy large rings

In hot rolling of a titanium alloy large ring (TLR), blank sizes have a considerable effect on the geometric shape of the deformation zone (GSDZ) which is closely related to the uniformity of strain and temperature distributions (STD) in the TLR. In the study, an analytical description of the GSDZ is presented and then a reliable 3D coupled thermo-mechanical FE model of the process is developed based on ABAQUS/Explicit. Size effects of rectangular-section blanks on the uniformity of STD in TLRs are explored from the GSDZ point of view using dynamic explicit FE simulation. The results obtained show that: (1) The GSDZ can be described by the average shape parameter G¯ and the average distribution ratio of feed amount γ¯. (2) Under the plastic stability condition, decreasing the blank thickness h0 or increasing the average blank radius Ra0 leads to more uniform STD, while the blank axial height b0 has a negligible effect on the uniformity of STD. Moreover, there exist differences between effects of the two means for changing h0 (i.e. change the blank outer radius R0 or change the blank inner radius r0). (3) R0 has predominant effect on the uniformity of STD, followed by r0, Ra0 and b0 in turn.