Research On Inertia Friction Welding Of GH4169 Super-alloy And Its FE Numerical Simulation

Inertia friction welding (IFW) is an advanced solid state joining process, which has the characters of excellent efficiency and energy-saving. It has been pretty extensively used in many industry fields, such as automobile,aerospace,automobile and energy, as a result of the features of less process parameters,high automation, steady quality of welding joints and so on.Conventional inertia friction welding process usually includes big inertia, low rotational speed and powerful axial pressure, under consideration for welding automation and making welding line steady excellent performance and reappearance. In these conditions, it is easy to find of lower temperature-peak in friction interface, easily inducing heat affected zone (HAZ) extending, hardly controlling joint quality because of huge brake torque. In order to avoid these defects, IFW of GH4169 alloy with little inertia, high rotational speed and tow-rank axial pressure has been investigated in present dissertation. When forging, the phenomenon of transient rising of interface temperature is so explicit that flash appears in each process. According to microstructure analysis of welds, the joints have symmetry transition of grains which are finer than basic material's, no defects of un-welded, splash cracks, tear-flaws et; according to measure temperatures of joints in welding process, with the same input energy the higher rotational speed is, the higher temperature peak of interface appears, the less grads of axial temperature are, the more narrow HAZ is; the power forging pressure is, the clearer flashes take up, the shorter the time of instant increasing of interface temperature undergoes, the high peak temperature in interface arrives. On the base of these results, this paper states welds forming mechanism, comparing performance of weld lines in the condition of upper tow criterions, and summarizing several familiar detects of IFW.Meanwhile, referring to features of IFW under tow-rank pressure criterion, combining with large forming thermo-elastic-plastic theoretics in metal plasticity formation, virtual work principle and tribology rules, a tow-dimension axi-symmetric thermo-mechanical coupled finite element model was established to simulate temperature field and stress-strain fields of this process by using FEM analysis software ANSYS. In the case of thermal radiation and convection slightly effecting temperature field and no flash, this model calculates transient temperature field, stress-strain fields and plastic flow during welding in the terms of experimental speed and authorized boundary condition. Measuring temperature to validate simulation results, the calculated temperature agrees well with the experimental...