Continuous-drive friction welding of HT700 superalloy: Numerical simulation with an Arrhenius constitutive equation and experimental validation

A strain-compensated Arrhenius constitutive equation was established for the HT700 superalloy based on hot compression tests, achieving a correlation coefficient ( R ) of 0.987 and an average absolute relative error of 4.69%. The constitutive equation was incorporated into a two-dimensional axisymmetric finite-element model to investigate the thermo-mechanical behavior during continuous-drive friction welding. The model was experimentally validated, with an axial shortening error of only 1.2%. Increasing rotational speed and friction pressure accelerated flash formation and shortened the time required to reach the steady-state welding stage. The simulated thermo-mechanical history was consistent with the observed grain refinement, γ′ dissolution, and carbide evolution, elucidating the weld formation mechanism of the HT700 superalloy.