Through overall inspection, analysis and study on the saddle welding beam defect of lower gas-holding pipes, the cause of the defects was found and prediction was made on the residual life of furnace pipes, and repairing suggestion was given as well.

• 摘要通过对下集气管马鞍焊缝缺陷进行全面的检测、分析、研究，查清了缺陷产生的原因，预测了炉管的剩馀寿命，并提出了修复使用的建议。