乙烯裂解管线开裂成因分析  

Failure Analysis on Cracking of Ethylene Cracking Pipeline

作　　者：温宝峰 于永旺 李金梅 史伟 WEN Baofeng;YU Yongwang;LI Jinmei;SHI Wei(Shaanxi Coal Chemical Industry Technology Research Institute Co.,Ltd.,Xi'an 710065,Shaanxi,China;Lanzhou LS Test Technology Co.,Ltd.,Lanzhou 730314,Gansu,China)

机构地区：[1]陕西煤业化工技术研究院有限责任公司,陕西西安710100 [2]兰州兰石检测技术有限公司,甘肃兰州730314

出　　处：《热处理技术与装备》2025年第2期48-51,共4页Heat Treatment Technology and Equipment

摘　　要：某石化公司的乙烯裂解装置在开车升温过程中,多处管线接头部位开裂。采用化学成分分析、金相检验和SEM断口分析等手段对该接头进行了检验和分析。结果表明,该管线外壁的化学成分符合标准要求,管线内壁的碳含量高于标准要求。管线失效的原因是高温、高碳环境下服役导致管线内壁发生了碳扩散,且其服役温度处于不锈钢的敏化温度区间,碳原子与铬原子结合形成碳化物并沿奥氏体晶界析出,弱化了晶界,破坏了晶界的连续性,在外力作用下萌生微裂纹;开车升温过程中沿着应力集中部位,微裂纹进一步扩展最终导致管件开裂。During the start-up and heating process of an ethylene cracking unit in a petrochemical company,multiple pipeline joints cracked.The joint was inspected and analyzed using chemical composition analysis,metallographic examination and SEM fracture analysis,etc.The results showed that the chemical composition the outer wall of the pipeline met the standard requirements,but the carbon content of the inner wall the pipeline was significantly higher than the standard requirements.The reason for the failure of the pipe fittings was that carbon diffusion occurred on the inner wall of the pipeline due to service in a high temperature and high carbon environment.Due to its service temperature being in the sensitization temperatures range of stainless steel,it promoted the combination of carbon atoms and chromium atoms to form carbides and precipitate along austenite grain boundaries,weakening the grain boundaries,disrupting the continuity and inducing microcrack initiation under external forces.Microcracks propagated along the stress concentration areas during driving,ultimately leading to cracking of the pipe fittings.

关 键 词：管线 碳扩散 敏化温度 

分 类 号：TG142[一般工业技术—材料科学与工程]