乙烯裂解炉炉管损伤机理及剩余寿命评估

摘要

Through experimental study of the microstructure,microhardness and the mechanical properties of BA-101 Ethylene pyrolyzer tube,as well as basing on Larson-Miller curves,the tube damage mechanism and its residual life were analyzed and evaluated.The results show that after a 30 660h-long operation,the BA-101 ethylene pyrolyzer tube can encounter creep holes and the carburizing appears on the internal surface;and the different expansion coefficient between the tube’s carburized parts and uncarburized parts can make the mate-rial’s internal stress increased,this stress together with other stress can incur damages to the tube in the process of blowing down,and the residual life of BA-101 ethylene pyrolyzer tube working at 1 000 ℃ stays at about 17 000 h.%通过对 BA-101乙烯裂解炉炉管进行金相、显微硬度及力学性能等试验研究，分析了该炉辐射段炉管损伤的原因，基于金相分析结果和 Larson-Miller曲线评估与该炉管相同服役条件下其他炉管的剩余寿命。结果表明：BA-101乙烯裂解炉炉管运行30660h后晶界出现蠕变孔洞，且内表面发生一定程度的渗碳，炉管渗碳部分与非渗碳部分之间膨胀系数不同，造成材料内应力增加，该应力与其他应力共同作用使炉管在停炉过程中发生较大损害。BA-101乙烯裂解炉炉管在管壁正常操作温度（1000℃）时，剩余寿命约为17000h。