INSPECTION METHOD OF DEPTH FOR PEENING MACHINED LAYER AT INTERNAL SURFACE OF TUBE

摘要

PURPOSE:To make quantitative judgement for continuous inspection of non-destructive method, by detecting the unbalanced potential produced at the bridge circuit with eddy current. CONSTITUTION:After balancing the bridge circuit BRG, the reference tube of machined layer depth zero and the tube known for the machined depth t1 are inserted for the coils L1 and L2 of which impedance is changed with eddy current. The output level of the DC amplifiers DAX, DAY at that time is obtained, and similarly with the tube known for the machined depth t2 and inserted for the coil L2, the output level of the amplifiers DAX and DAY is obtained. Next, as to the tube to be inspected, the inspection is conducted as the same steps as mentioned above to check whether the output level of the amplifiers DAX, DAY at that time is between both output levels for the machined depths t1 and t2 or not. Thus, the depth of machined layer can quantiatively be judged.