Abstract:
Based on the analysis of steel tube end effect as produced during MFL detection and the mechanism for elimination thereof,an automatic MFL-based pipe-end NDT method,i.e.,the end-extending process is put forward,which involves such a work principle that a magnetic inductive structural unit is used to collect the MFL field at the tube end,and guide the tube end magnetic path,then,another magnetic inductive structural unit is adopted to joint with the tube end to make a new end,and thus,the original tube end becomes a part of the tube body itself to reduce the non-detection area of the tube end.Following this principle,the magnetic path-guiding device and transducers are designed.Detailed in the article are the main aspects of the automatic MFL-based pipe-end NDT system,including the configuration,the operation principle and the process flow of automatic tube-end detection.Thanks to the said NDT method and the system,the tube-end non-detection area can be reduced to less than 30 mm.