摘要
针对液态乙烷管道运行的安全性和可靠性问题,采用力学性能试验和失效评估分析的方法,对液态乙烷管道泄漏失压下的低温脆性、外载作用下的环焊接头应变能力变化进行了研究和分析,结果表明:当液态乙烷由液相转变为气相时,管壁温度高于管材的韧脆转变温度,管道发生低应力下的脆性断裂可能性较低。环焊接头失效模式主要为裂纹扩展失效时,拉伸应变与材料的断裂韧性高低有关;失效模式转变为颈缩失效时,拉伸应变与焊缝、母材的拉伸性能相关。裂纹尺寸较大时,环焊接头会发生断裂失效;裂纹尺寸较小时,失效模式则会转变为焊缝、母材的塑性失效,轴向拉伸应变较高。
In view of the operation safety and reliability of liquid ethane pipeline,mechanical tests and failure assessment method are used to study the low-temperature brittleness of liquid ethane pipeline under leakage and loss of pressure,and the changes of strain capacity for girth welded joints during external load.The results show that the temperature of the wall of the pipeline is higher than the ductile-brittle transition temperature of the pipe as liquid ethane is transformed from the liquid to the gas,and the brittle fracture hardly occurs under low stress.When the failure mode of the girth welded joint is crack propagation,the tensile strain is related to the toughness of the material.When the failure mode changes to necking,the tensile strain is related to the tensile properties of the weld or the base material.When the crack size is larger,the failure mode of girth welded joint may be fracture.When the crack is small,it will change to plastic failure of the weld or base material,and the axial tensile strain is higher.
作者
杨坤
王俊
李鹤
李胜男
池强
YANG Kun;WANG Jun;LI He;LI Shengnan;CHI Qiang(State Key Laboratory of Oil and Gas Equipment,CNPC Tubular Goods Research Institute,Xi′an,Shaanxi 710077,China)
出处
《石油管材与仪器》
2024年第4期55-59,共5页
Petroleum Tubular Goods & Instruments
关键词
液态乙烷管道
环焊接头
韧脆转变
拉伸应变
liquid ethane pipeline
girth welded joint
ductile-brittle transition
tensile strain
