中文摘要：

差别处理被用来，从直接当前的磁性的流动漏(DC-MFL ) 信号在一根钢管子的内部、外部的表面上人工地用机器制造的缺点发出。因而，区别索引的地点被提供识别缺点它是否在内部表面或外部表面上。缺点的三个特征，形状，深度和取向，通过人工的缺点的一系列实验被讨论钢上的倾斜的槽口和坑例如横向的槽口，尖叫。途径被验证了对地址有效识别问题的缺点地点，虽然在到在服务的钢管子上的那些自然缺点的精确性评价以后的限制。

英文摘要：

Difference processing was used to the direct current magnetic flux leakage （DC-MFL） signal, emanating from the defects machined artificially on the internal and external surfaces of a steel pipe. Consequently, the loea-tion discriminating index 8 was provided to identify the defect whether it is on the internal surface or the external one. Three characteristics, shape, depth and orientation of the defect, were discussed through a series of experiments on the artificial defects, such as transverse notches, oblique notches and pits on the steel pipe. The approach has been verified effective to address the defect location identifying problem, albeit the limits on the accuracy assessment to those natural defects on steel pipes in service.