奥氏体不锈钢小径管焊缝超声波相控阵检测技术应用及分析

Application and analysis of ultrasonic phased array detection technology for austenitic stainless steel small diameter tube weld

针对奥氏体不锈钢小径管焊缝的失效机理和裂纹缺陷特点,研究制定了专用超声波相控阵检测技术,并确定了验收标准及裂纹判断方法,选取35条焊缝进行现场试验验证。结果表明:超声波相控阵不合格焊缝与内表面液体渗透检测结果基本一致;超声波相控阵与射线检测约50%焊缝结果一致,超声波相控阵和射线检测均存在裂纹漏检。通过理论、试验结果及试验数据统计分析,得出超声波相控阵技术能够有效检测出役致裂纹;超声波相控阵技术在单侧扫查时,对探头对侧焊缝区域裂纹缺陷检出率低,容易发生漏检;超声波相控阵技术对于高度较小的裂纹,容易误判缺陷性质;射线检测对役致裂纹的检出率低,从检测结果统计分析可得出,检出率低于超声波相控阵技术。

Aiming at the failure mechanism and crack defect characteristics of austenitic stainless steel small diameter pipe welds,a special ultrasonic phased array detection technology was developed,and the acceptance criteria and crack judgment method were determined.The field test was verified by 35 welds.The test results show that the ultrasonic phased array unqualified weld is basically consistent with the liquid surface penetration test on the inner surface.Ultrasonic phased array and ray detection are consistent with about 50%weld results,and ultrasonic phased array and ray detection have crack miss detection.Through theoretical analysis,experimental results analysis and statistical analysis of experimental data,it is concluded that ultrasonic phased array technology can effectively detect cracks caused by service;ultrasonic phased array technology detects crack defects in the opposite side of the probe during one-side scanning.Low rate is easy to miss detection.Ultrasonic phased array technology is easy to misjudge the defect properties for small cracks;the detection rate of ray-induced cracks is low.From the statistical analysis of the test results,the detection rate is lower than the ultrasonic phased array technology.