裂解炉辐射段新旧炉管焊接方法改进

IMPROVEMENT OF WELDING METHOD FOR OLD AND NEW FURNACE TUBES IN RADIATION SECTION OF CRACKING FURNACE

乙烯装置裂解炉辐射段炉管常用材质有25Cr35NiNbMA及35Cr45NiNbMA两种高温合金材料,焊接方法均采用氩弧焊。文章通过分析辐射段新旧炉管的组织差异、材料的可焊性,针对因材料大块析碳导致新旧炉管组对焊接时采用普通氩弧焊存在的一次焊接成功率低问题,提出采用局部高温锻造+氩弧焊焊接方法,大幅提高了新旧炉管组对首次焊接的成功率,进而缩短因裂解炉炉管损坏导致的检维修周期。

Two kinds of high temperature alloy materials of 25 Cr35 NiNbMA and 35 Cr45 NiNbMA were commonly used in furnace tubes of radiant section in the cracking furnace in ethylene production plant, and the welding method was argon arc welding. Basing on analysis of microstructure difference between the new and old furnace tubes in radiation section and material weldability,in order to solve the problem of low success rate of one-time pairing welding of new and old furnace tubes by ordinary argon arc welding due to carbon deposition from the large material,the welding method of local high temperature forging and argon arc welding was proposed. Success rate of the first pairing welding of the new and old furnace tubes was greatly improved,and the inspection and maintenance period caused by the damage of cracking furnace tubes was shortened.