APPLICATION OF SINTAP TO THE SAFETY ASSESSMENT OF X65 PIPELINE STEEL

摘要

The recently developed European flaw assessment procedure, structural integrity assess-ment procedure(SINTAP) is applied to assessment for welded joints of the API 5L X65 pipeline steelwith an assumed embedded flaw and surface flaw at the weld toe. As one of the basic input data,fracture toughness crack tip opening displacement (CTOD) tests are conducted at 0 "C and performedaccording to the requirements of the standard of BS7448. For the heat affected zone (HAZ) speci-mens, the microstructure observation is performed to insure that the tip of the crack is located in thecoarse grain zone. The result explains the dispersity of the test values. In structural integrity assess-ment procedure-fracture assessment diagram(SINTAP FAD) method, the failure curves of weldedjoints at level 1 and 3 are derived from the tensile test results. The results of the assessment show thatall assessment points are located within the failure lines of analysis level 1 and 3. So the welded jointof the pipeline is safe. This study laid the foundation of application of SINTAP to pipeline structureassessment.