Abstract: A 2-D finite element model of inertia friction welding of GH4169 tubular was established based on the ABAQUS environment.The effect of axial pressure on the temperature field and axial upset of the joint was investigated by adopting the remeshing technique.The variations of joint temperature field under different axial pressures were also expounded.Moreover,according to the change of axial upset,the effect of axial pressure on the flash shape was analyzed.The results show that increasing axial pressure can significantly raise the conversion efficiency from flywheel kinetic energy to weld heat,shorten the time to high temperature quasi-steady state,and obtain flash shape.However,an extensively large pressure is negative to temperature field uniformity,which may result in bad stress concentration.At last,the pressure of 400 MPa is supposed to be a good parameter in this study.