压力容器2024，Vol.41Issue(12)：51-59,9.DOI:10.3969/j.issn.1001-4837.2024.12.007
乙烯装置裂解炉废热锅炉封头法兰失效原因分析
Failure analysis of head flange of waste heat boiler of cracking furnace in ethylene plant
摘要
Abstract
To investigate the leakage failure of the head flange in a waste heat boiler of an ethylene cracking furnace at a petrochemical plant,a comprehensive failure analysis was conducted using chemical composition analysis,microstructure examination,mechanical property testing,and scanning electron microscopy(SEM).The results revealed that the base metal of the flange exhibited normal chemical composition,while the heat-affected zone(HAZ)retained a typical austenitic microstructure but showed extensive secondary phase precipitation.This region exhibited a significant reduction in elongation,increased hardness,and brittle fracture surfaces characterized by cleavage and quasi-cleavage patterns.The failure mechanism was attributed to prolonged high-temperature exposure(exceeding 800℃),which promoted intergranular carbide precipitation(secondary phases)in 2520 stainless steel,leading to intergranular embrittlement and material degradation.Repeated thermal cycling during operation generated cyclic thermal and tensile stresses,initiating crack nucleation at structural discontinuities(e.g.,the junction between the flange disc and neck),where stress concentration and material degradation were most severe.These cracks progressively propagated into macroscopic defects.Preventive control measures were proposed to mitigate similar failures and minimize operational losses.The findings provide critical insights for the maintenance and management of waste heat boiler systems in industrial applications.关键词
乙烯裂解炉/废热锅炉/封头/失效原因/控制措施Key words
ethylene cracking furnace/waste heat boiler/head flange/failure mechanism/control measures分类
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王明涛,毕学文,王东,李廷取,王冬雷..乙烯装置裂解炉废热锅炉封头法兰失效原因分析[J].压力容器,2024,41(12):51-59,9.基金项目
国家自然科学基金面上项目(22278172) （22278172）
