摘要
[目的]长输管道在建设与运行期间不可避免会受到应变时效的影响,导致管道母材与环焊缝的力学性能发生劣化,影响服役安全。随着高钢级X80管道的规模化应用,探究高钢级管道环焊接头应变时效特性及规律对保障管道安全服役具有重要意义。[方法]选取等强匹配X80钢制管道环焊接头作为研究对象,通过标准冲击实验与小尺寸拉伸实验研究环焊接头经不同温度及周期时效处理后的力学性能变化规律;基于大量实验数据与理论模型,建立了X80管道环焊缝应变时效临界劣化时间预测模型。[结果]相较于单一预应变处理或单一高温时效处理,应变时效处理后环焊缝的冲击韧性显著降低,降幅可达68.5%;应变时效处理后,X80钢的应力-应变曲线由“圆屋顶型”转变为“吕德斯型”,材料强度升高、塑性降低;随着时效温度、时效周期的增加,焊缝材料的塑性变形能力急剧劣化。[结论]通过所建应变时效临界劣化时间预测模型,预测得到在服役温度为20℃的条件下,若X80钢环焊缝发生应变集中,其韧性将于约119.7 d后劣化至无法满足安全服役要求。研究成果可为高钢级管道环焊缝应变时效的认识、防治及控制提供数据支撑与理论指导。
[Objective]Long-distance pipelines inevitably experience strain aging during construction and operation,which impacts service safety.With the large-scale application of high-grade X80 pipelines,it is essential to investigate the strain aging characteristics and rules of girth weld joints to ensure their safe operation.[Methods]The study focused on the equal-strength X80 steel pipeline girth weld joints.Standard impact and small-scale tensile tests were conducted to investigate the mechanical property changes of girth weld joints at various aging temperatures and periods.Using extensive test data and theoretical models,a prediction model for deterioration time of X80 pipeline girth welds under strain aging was established.[Results]In comparison to single pre-strain treatment or single high-temperature aging treatment,the impact toughness of girth welds subjected to strain aging was significantly reduced by 68.5%.After strain aging,the stress-strain curve of X80 steel transitioned from“round-house type”to“Luders type”,with an increase in strength and a decrease in plasticity.Additionally,as aging temperature and periods increased,the plastic deformation capacity of the weld material deteriorated sharply.[Conclusion]Based on the established strain aging prediction model,it is predicted that strain concentration in the girth weld of X80 steel at a service temperature of 20℃ will lead to a deterioration in toughness after approximately 119.7 days,rendering it inadequate for safe service.The research results can provide valuable data and theoretical guidance for understanding,preventing,and controlling strain aging in the girth welds of high-grade steel pipelines.
作者
范玉然
帅义
张铁耀
帅健
张怡
高唯
石磊
张俊杰
FAN Yuran;SHUAI Yi;ZHANG Tieyao;SHUAI Jian;ZHANG Yi;GAO Wei;SHI Lei;ZHANG Junjie(College of Safety and Ocean Engineering,China University of Petroleum(Beijing)//Key Laboratory of Oil and Gas Safety and Emergency Technology,Ministry of Emergency Management;PipeChina Engineering Technology Innovation Co.,Ltd.;SINOPEC(Dalian)Research Institute of Petroleum and Petrochemicals Co.,Ltd.)
出处
《油气储运》
北大核心
2025年第2期184-193,共10页
Oil & Gas Storage and Transportation
基金
国家自然科学基金资助项目“纳入裂尖多尺度拘束效应的X80管道环焊缝断裂评估方法研究”,52204071
中国石油大学(北京)优秀青年学者科学基金资助项目“高强钢管道环焊缝断裂机理及应变能力研究”,2462023QNXZ006
国家重点研发计划子课题“基于内检大数据的城市燃气管道服役状态综合评价与决策技术研究”,2022YFC3004802-4。
关键词
油气管道
X80钢
环焊缝
冲击韧性
力学性能
应变时效
oil and gas pipeline
X80 steel
girth weld
impact toughness
mechanical property
strain aging
