摘要
采用金相、断口扫描电镜等手段对投用4年的裂解炉管6 m高度处的裂纹进行了分析。裂纹起源于外表面,呈多条平行分布沿周向扩展。分析表明,炉管微观组织正常,没有大量碳化物积聚和蠕变空洞,外表面有轻微的脱碳层,表明炉管没有超温迹象。炉管开裂是由热疲劳所致。热疲劳是由于炉管烧焦期间升降温产生的交变热应力和机械应力共同作用造成的。
The failure of ethylene cracking tubes at an elevation of about 6 m in radiant chambers after 4 years'operation has been analyzed by means of optical microscopy,scanning electron microscopy (SEM) and energy dispersive spectrometer(EDS). The investigation showed that the cracks,which originated from the outer surface,are circumferential and parallel.The analysis revealed that no significant growth and deposit of carbide and creep voids were found on the microstructure and no evidence of overheat was found at the failed tube.The cracks are caused by thermal fatigue,which results from the combined action of thermal stress caused by decoking and mechanical stress.
出处
《乙烯工业》
CAS
2009年第3期49-51,共3页
Ethylene Industry
关键词
裂解炉管
HP40钢管
热疲劳
Ethylene cracking tube
HP40 steel tube
Thermal fatigue
