旧裂解炉管焊接常见缺陷探讨

作为炼化裂解炉的核心部件,高铬镍耐热钢炉管常因积焦堵塞、蠕变爆管等原因需要割管并修复。长期运行的炉管在焊接修复时,由于炉管组对不稳定、管内壁碳侵蚀严重、管材合金成分高以及导热系数小等原因,常出现坡口质量差、底层晶间腐蚀、热裂纹缺陷。针对形成原因,采用便捷卡具、适度磨除碳蚀层、确定小热量输入等焊接措施可以避免这些缺陷的产生。

Research on welding defects of old cracking furnace tube

As the core component of cracking furnace,the high cr-ni content of heat resistant steel furnace tube needs to be cut and repaired because of petroleum coke blocking and creep-deformation tube burst.In the welding repair of long-running furnace tube,some defects are often appeared,such as poor quality of groove,bottom intergranular corrosion and hot cracks,which due to unsteady tube group,severe carbon erosion on the inner wall of the tube,as well as the high alloy composition and small coefficient of heat conductivity of the tube.Hence,some welding measures like convenient fixture,appropriate removal of carbon corrosion layer and using small heat input are adopted to avoid these defects.