高钢级管线钢焊接接头热影响区冲击试验结果分散性较大，为了研究其冲击吸收能量波动的影响因素，对X70埋弧焊钢管焊接接头熔合线位置的冲击试验结果进行了分析。结果表明：X70埋弧焊钢管焊接接头热影响区熔合线位置冲击吸收能量较低，但在-10℃试验温度下，熔合线位置平均冲击吸收能量也达到了100 J以上；X70埋弧焊钢管焊接接头热影响区熔合线冲击吸收能量的显著波动是由刻槽位置的偏差及裂纹扩展走向的不确定性引起的。

The impact test results of heat affected zone of welded joints of high-grade pipeline steel were more dispersive. In order to study the influence factors of impact absorption energy fluctuation, the impact test results of fusion line position of welded joint of X70 submerged arc welded steel pipe were analyzed. The results show that the impact absorption energy by the fusion line in heat affected zone of welded joint of X70 submerged arc welded steel pipe was low, but the average impact absorption energy by the fusion line was over 100 J at the test temperature of -10℃. The significant fluctuation of impact absorption energy by the fusion line in heat affected zone of welded joint of X70 submerged arc welded steel pipe was caused by the deviation of groove position and the uncertainty of crack propagation direction.