X80管线钢电磁超声残余应力检测精度的影响因素

Influencing factors of electromagnetic ultrasonic residual stress detection accuracy of X80 pipeline steel

管道运输中X80管线钢应用较为广泛,实际管道焊接大多使用半自动焊,难免存在焊接缺陷,在使用过程中会造成应力集中,可能导致管道破裂、石油泄漏等重大事故。为了促进电磁超声残余应力检测在管线钢中的应用,采用电磁超声系统,测试了X80管线钢残余应力检测的最佳参数。试验结果表明,电磁超声残余应力检测系统的6次回波测试精度为60 MPa;得出了电磁超声残余应力检测应力系数、信噪比随回波次数的变化关系,回波次数和应力系数、信噪比之间存在最佳取值,最后对薄板、厚板的电磁超声残余应力检测提出了一些建议。

X80pipeline steel is widely used in pipeline transportation.Semi-automatic welding is mostly used in actual pipeline welding,which inevitably leads to welding defects and stress concentration in the process of use,resulting in major accidents such as pipeline rupture and oil leakage.In order to promote the application of electromagnetic ultrasonic residual stress detection in pipeline steel,this paper tested the best parameters of residual stress detection in X80pipeline steel by electromagnetic ultrasonic system.The test results show that the accuracy of electromagnetic ultrasonic residual stress detection system was 60 MPa by choosing 6th echoes signal.The relationship between stress coefficient/signal-to-noise ratio(SNR)and echo times in electromagnetic ultrasonic residual stress detection was obtained through experiments.There is an optimal value between echo times and stress coefficient/SNR,and some suggestions were put forward for electromagnetic ultrasonic residual stress detection in thin and thick plates.