超声滚压加工对X80管线钢焊接残余应力的影响

建立超声表面滚压加工（ultrasonic surface rolling process，USRP）的三维有限元模型，开发了模拟焊接的移动双椭球热源子程序，利用有限元软件ABAQUS模拟了X80管线钢焊缝不同方向的焊接残余应力，在此基础上叠加USRP的超声振动与静载荷的综合作用，模拟了表面塑形变形、应力和应变，耦合后分析了USRP前后残余应力的变化规律.结果表明，经过USRP处理，X80管线钢表面焊缝区由三向残余拉应力变为三向残余压应力，随着USRP次数的增加，残余压应力数值不断增大，残余应力σ_x，σ_y，σ_z变化规律基本相同.

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.