摘要
针对某站场脱水装置重沸器烟火管发生开裂失效问题,采用宏观形貌分析、拉伸性能试验、金相组织分析和扫描电镜及能谱分析等方法研究了该管道失效原因。结果表明其失效的主要原因是:因烟火管的结构特点产生的局部高温和富三甘醇杂质的沉积,使局部高温处形成盐垢;盐垢下的钢管与水蒸汽在高温下发生氧化反应,形成腐蚀,使管体壁厚减薄。局部高温和化学反应热的共同作用,使钢管发生局部的膨胀变形,形成内凹形变。在腐蚀、热应力、管体塑性形变等外因素的共同作用下,裂纹萌生和扩展,最终穿透整个管壁。通过提高副烟火管与主烟火管结构部位处溶液的流动性,减少因杂质的沉积产生的局部高温区域的面积是预防此类失效的有效措施。
Aiming at the fracture failure of the pyrotechnic tube of the reboiler of dehydration unit in a natural gas station,the failure reason of the tube was studied by means of macroscopic morphology analysis,tensile property test,metallographic structure analysis,scanning electron microscope and energy spectrum analysis.The results show that the main reasons for the failure are local high temperature and the deposition of triglycol-rich impurity caused by the structural characteristics of the pyrotechnics tube,which resulted in the formation of salt scale at the high temperature location.The oxidation reaction between the steel tube under the salt scale and the water vapor at high temperature resulted in the formation of corrosion and the thinning of the tube wall.The joint action of local high temperature and chemical reaction heat causes local expansion deformation of steel tube,forming concave deformation.Under the combined action of corrosion,thermal stress,plastic deformation and other external factors,cracks initiate and propagate,and finally penetrate the whole wall thickness to form fracture.The important measures to prevent such failure are to improve the fluidity of the solution at the structure parts of the secondary main pyrotechnic tube and the main pyrotechnic tube and to reduce the local high temperature area caused by the deposition of impurities.
作者
鲍明昱
高健
张晓琳
熊建嘉
BAO Mingyu;GAO Jian;ZHANG Xiaolin;XIONG Jianjia(Safety, Environment & Technology Supervision Research Institute, PetroChina Southwest Oil & Gas Field Company, Chengdu, Sichuan 610041, China;Science and Technology Department of CNPC Chuanqing Drilling Engineering Company Limited, Chengdu, Sichuan 610051, China;PetroChina Gas Storage Company, Beijing 100029, China)
出处
《石油管材与仪器》
2022年第1期45-49,共5页
Petroleum Tubular Goods & Instruments
基金
“十三五”国家科技重大专项“四川盆地大型碳酸盐岩气田开发示范工程”(编号:2016ZX05052)
中国石油西南油气田分公司博士后工作站科学研究与技术开发项目“输送含硫天然气介质的站场承压类静设备检测评价技术研究”(编号:20190305-12)。
关键词
重沸器
塑性变形
开裂
腐蚀
失效分析
reboiler
plastic deformation
fracture
corrosion
failure analysis
