建立了含热影响区裂纹X80焊接管道模型，模拟了残余应力分布并进行了验证；采用有限元方法模拟得到有、无焊接残余应力以及不同裂纹尺寸下焊接管道的极限内压，并与ASME B31G标准、DNV RP-F101标准和PCORRC方法计算得到的进行对比；结合PCORRC方法和有限元模拟结果修正了极限内压计算公式。结果表明：无论是否存在焊接残余应力，焊接管道的极限内压均随裂纹深度或长度的增大而降低，且焊接残余应力对极限内压的影响随裂纹长度的增大而减小；3种方法计算得到的极限内压均随裂纹深度的增大而降低，但裂纹越深，计算结果与模拟结果的误差越大；采用修正公式计算得到含表面裂纹管道和含热影响区裂纹焊接管道的极限内压和模拟结果的相对误差分别在8%，7%以内，说明此极限内压计算公式具有一定的工程适用性。

Model for X80 welded pipeline containing heat affected zone crack was estabilished, and residual stress distribution was simulated and verified. Ultimate internal pressures of welded pipeline with and without welding residual stress and with different crack size were simulated by finite element method, and compared with those calculated by ASME B31G, DNV RP-F101 and PCORRC methods, respectively. The ultimate internal pressure equations were modified on basis of the results by PCORRC method and finite element simulation. The results show that whether the welding residual stress existed or not, the ultimate internal pressures of the welded pipeline all decreased with increasing depth or length of the crack. The effect of welding residual stress on ultimate internal pressure decreased with increasing crack length. The ultimate internal pressures by three methods decreased with increasing crack depth. The higher the crack depth, the larger the error between calculation and simulation. The relative errors between the calculation by matified equations and the simulation of the ultimate internal pressures of pipeline with surface crack and welded pipeline with heat affected zone crack were below 8% and 7%, respectively, indicating that the modified equations for ultimate internal pressure can be used for practical engineering.