美标管材超声波测厚仪测厚异常的失效分析

Failure Analysis on Abnormal Thickness Measurement of American Standard Pipe Ultrasonic Thickness Meter

美标管材使用超声波测厚仪测厚发现壁厚异常;进一步UT探伤验证,未发现分层缺陷,但是存在未超过ASTM E213标准的缺欠。对壁厚异常处进行金相分析,发现大量非金属夹杂物存在,美标材料标准未涉及对非金属夹杂物检验的结果判定。因此,对于美标材料的采购和使用时,应在合同或技术文件中增加非金属夹杂物的等级要求,避免管材检测出现此类缺陷无据可依。

The thickness of American standard pipe was measured by ultrasonic thickness gauge to find the wall thickness anomaly.Further UT inspection showed that no delamination defect was found,but there was a defect not exceeding ASTM E213 standard.Metallographic analysis was carried out on the abnormal wall thickness,and a large number of non-metallic inclusions were found.The American standard material standards did not involve the determination of the results of the non-metallic inclusion test.Therefore,when purchasing and using the American standard materials,the grade requirements of non-metallic inclusions should be added to the contracts or technical documents to avoid such defects in pipe testing.