Effect of ultrasonic rolling processing of X80 pipeline steel on welding residual stress

A 3D finite element model about ultrasonic surface rolling process was established and a moving double ellipsoid welding heat source was developed. By using the finite element software ABAQUS, welding residual stresses of the X80 pipeline steel in different direction were simulated, it combined ultrasonic vibration with static load at the basement of the USRP to simulate surface shape deformation, stress and strain. After coupling, the variation regularity of residual stress before and after USRP was analyzed. The results show that the residual stress of weld zone on the surface of X80 pipeline steel has changed from three-dimensional residual tensile stress into three-dimensional residual compressive stress through USRP processing. With the increase of the counts of USRP, residual compressive stress increases and the residual stresses in different directions σ_x, σ_y and σz have the similar variation trends.