Abstract:The flow behaviour and flash formation of ring component for 45^# steel in continuous drive friction welding (CDFW) process were investigated. A 3D thermo-mechanical coupled finite element method was used to conduct this research. Seven welding schemes with different friction pressures, friction times and rotational velocities were carried out. The influences of friction pressure, friction time and rotational velocity on the material flow behaviour at the friction surface and flash formation were analyzed. Research results show that higher peak temperature, larger region with high temperature and larger axial pressure are all good for the increase of material flow velocity. During the CDFW process, the material near the edge of friction surface flows towards the outside of joint, which makes the appearance of flashes. With the increase of rotational velocity, friction time and friction pressure, the dimensions and the bending degree of flashes increase. The reasonable welding parameters of ring structure for 45^# steel, whose inner diameter and outer diameter are 50 mm and 80 mm, respectively, are the friction pressure of 100 MPa, the friction time of 4 s and the rotational velocity of 1600 r/min.

Key words: continuous drive friction welding (CDFW); 45^# steel; temperature field; material flow; flash; finite element simulation; welding parameters