海底管线用钢焊接接头的安全评定及寿命预测

焊接接头是海底油气输送管道焊接结构中的薄弱环节，作者在给定裂纹尺寸和载荷条件下，根据裂纹尖端张开位移CTOD试验结果，采用欧共体提出的结构完整性评定方法SINTAP，对API5LX65管线钢焊接接头焊趾处的表面裂纹进行评定，根据拉伸试验结果，给出了X65管线钢焊接接头焊缝和母材的一级与三级评定曲线，结果表明，不论采用一级还是三级评定，各评定点均在评定曲线定义的范围内，说明该结构是安全的，根据评定结果对结构进行疲劳寿命估算具有工程实际意义和经济价值。

Safe Assessment and Life Prediction of Weld in Offshore Pipeline

According to the results of the CTOD (crack tip opening displacement) test and the SINTAP (structural integrity assessment procedure) suggested by the European Community, the assessment was carried out of the surface flaw at the toe of a weld in API 5LX65 pipeline with the given crack size and load being known. Based on the tensile test results of the base metal and weld metal, the assessment diagrams of Level 1 and Level 3 were constructed. The assessment results indicate that all the assessment points are within the region defined on the failure assessment diagrams using both Level 1 and Level 3. Therefore, the structure is safe, and the fatigue life was calculated in accordance with the above assessment. The study has practical significance in engineering and economic value.