Ductile-brittle Transition and Reliability of Welded Joints for Liquid Ethane Pipelines
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 transi-tion 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.
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维普
