DESIGN BASED ON DUCTILE-BRITTLE TRANSITION TEMPERATURE FOR API 5L X65 STEEL USED FOR DENSE CO2 TRANSPORT
Safe and reliable transport of dense CO2 by pipes needs a careful choice of the constitutive pipe materials to prevent brittle crack propagation after ductile or brittle failure initiation.This unexpected phenomenon can occur after failure or leak promoted by external interferences.In this case,the rapid decompression of dense CO2 into gas leads to a very low local temperature of about -80°C.To prevent risk of brittle fracture initiation and propagation,the material must remain ductile at this temperature.In other terms,its ductile-brittle transition temperature (DBTT) has to be lower than -80°C minus a margin.It is admitted that the DBTT is not a material characteristic but depends on specimen geometry,loading rate and loading mode,i.e.on constraints.A loss in constraint leads to a lower brittle-ductile transition temperature.In order to select a steel for transportation of dense CO2,transition temperatures Tt (from tensile test),TK27 and TK50 (from Charpy test) and TK100 (from fracture mechanics test) have been determined on an API 5L X65 pipeline steel.These transition temperatures have been reported versus a constraint parameter,e.g.T-stress,in a master curve.Differences between different brittle-ductile transition temperatures and temperature corresponding to T-stress acting in a pipe submitted to internal pressure on the master curve,give an estimation of the conservatism of the chosen reference transition temperature.
transition temperature pipe steel API 5L X65 constraint T-stress CO2 transportation
G Pluvinage J. Capelle Z. Azari
Fiabilité Mécanique.Conseils Silly sur Nied France LABPS.ENIM Metz France
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）