油气输送焊管残余应力测试与安全评价方法研究

针对油气输送焊管残余应力测试与评估技术难题,采用机械切割应力释放法对不同成型工艺和状态焊管的残余应力进行了测试分析对比,结果表明:UOE焊管的残余应力分布水平较低;ERW焊管次之;SSAW焊管的残余应力分布范围较广,有高有低。不同管型和成型工艺及水压试验状态具有明显不同的残余应力分布特征,在进行焊管安全评价时必须区别对待。根据残余应力实测结果提出了焊管安全评价时残余应力的取值建议。研究结果对管道设计、安全分析与评价、焊管残余应力的改善、控制及焊管合理选用具有重要工程意义。

Research on Residual Stress Test of Welded Steel Pipes for Oil and Gas Transportation and Its Safety Assessment Method

Aiming at the difficulty in testing and assessing the residual stress of welded steel pipes for oil and gas transportation, a mechanical cutting stress release method is used to test the residual stress of vari- ous welded steel pipes. Comparative analysis shows that the residual stress distribution is narrowest for U- O-E formed pipes, middle for Electric-Resistance-Welded pipes, and widest for Spiral-Submerged-Arc- Welded pipes. Pipes with different forming and welding procedures and different hydrostatic test have distinct characteristics of residual stress distribution, and this shall be differently considered during safety as- sessment. It is suggested that the value of residual stress should be decided according to the actual result of residual stress test during safety assessment. All the research is of great value for the pipe design, pipe safety analysis and assessment, the improvement of pipe residual stress and the selection of pipes.