Magnetic flux leakage testing theory and method for magnetizer end inspection

Faults and accidents occur easily in the end area of the common industry magnetizers like sucker rods, oil well tubings and drill pipes. But there isn't any effective or accurate testing method for the end area inspection at present. The end area is considered as the testing blind area with Magnetic Flux Leakage (MFL) testing method generally. In the light of this status, an innovative method using MFL theory, called the whole end area magnetization and points scanning detection method, is brought forward to solve the end area magnetization difficulty and the inspection problem for the abnormity end area in this paper. This method has been used in the inspection of the upset forging parts of sucker rods successfully. It can inspect the end area defects like cracks and corrosions effectively and accurately and realize the non-blind testing of some industry magnetizers.