The Evaluation of Pulsed Eddy Current Technique for Detection and Characterization of Surface Defect in Carbon Steel Welded Sample: An Experimental Study

Pulsed Eddy Current (PEC) is an advanced Non-Destructive Testing (NDT) method based on the principles of electromagnetic induction which generate square wave form. This study was carried out to investigate the surface defect that occurs in carbon steel welded sample (ASTM A36) and to investigate the signal profile of a transverse crack orientation with different defect depths which are 1mm, 2m, 3mm, 4mm and 5mm. A total of five test samples have been used to execute this study with different defect depths. MATLAB is used to generate the result and from the result, it shows that transverse crack is inversely proportional where the deeper the crack, the lower the magnetic field where the magnetic field dropped by 3.54% from 1mm to 2mm of defect depths. However, 3mm of defect depth decreased by 5.55% when compared to 2mm. Meanwhile, with defect depths of 4mm and 5mm, each magnetic field reduced by 2.59% and 4.91%, respectively. This is due to the changes of relative permeability and electrical conductivity of the test sample after welding process been done and affected the magnetic field that acquired. Therefore, it shows that PEC is an effective method of NDT in order to detect the surface defect carbon steel.