某芳烃厂二甲苯车间加热炉在使用5万h后发生爆管, 对爆裂炉管的显微组织和力学性能进行测试, 并利用大型有限元软件ABAQUS模拟了焦层厚度对炉管热应力分布的影响, 最后对爆裂炉管的失效原因进行了分析。结果表明: 结焦引起炉管局部超温导致珠光体球化, 从而使炉管的力学性能降低, 在内压和热应力的共同作用下炉管爆裂。

Coking burst heating furnace tube in a xylene workshop with 20 steel after using 50 000 h had been comprehensively investigated by observing the microstructure and testing the mechanical properties at room temperature. Large finite element analysis software ABAQUS was used to simulate that the effect of coke layer thickness on the heat stress distribution in the furnace. The results show that the overtemperature happend on part of the tube because of coking, and resulted pearlite spheroidization, thus, the mechanical properties of the tube decreased, and the tube bursted at the combined action of internal pressure and heat stress.