Oil and gas pipelines may deform under the influence of various geological disasters and other abnormal loads during long-term operation,leading to pipeline safety accidents.Regular stress testing of in-service pipelines is an effective means of evaluating pipeline safety.In order to explore more suitable stress detection methods for in-service pipelines,tensile tests were conducted on X70 and X80 steel plates,the main materials of in-service pipelines.The stress of the steel plates under different loads was measured using ultrasonic method,magnetic anisotropy method,and coercive force method,and the stress test results obtained from the three testing methods were analyzed.The results showed that in 8 sets of uniaxial tensile experiments,by fitting and analyzing the experimental values with the true values,5 sets of experimental data from the ultrasonic method had a goodness of fit above 0.99;In the biaxial tensile test,the ultrasonic method has the best fitting linearity,while the data fitting effects of the coercive force method and magnetic anisotropy method are relatively discrete.In the coercive force experiment,with the increase of lift off value,both axial and circumferential coercive forces show a downward trend,and the detection signal of magnetic anisotropy method also shows a downward trend with the increase of lift off value;In temperature experiments,the results of ultrasonic testing show a linear increase with increasing temperature,while the measurement results of coercive force show an overall downward trend with increasing temperature.The measurement results of magnetic anisotropy technology show a trend of first increasing and then decreasing with increasing temperature.By comparing and analyzing the test results of three methods,the ultrasonic method has the highest accuracy in stress detection of in-service pipelines,indicating the direction for selecting more efficient non-destructive testing methods for future in-service oil and gas pipelines.
stress nondestructive testingcomparative studyultrasonic methodcoercive force methodmagnetic anisotropy method
万方数据
维普
