Research on pulsed eddy current automatic detection technology for weld defects of pressure vessel cylinder

•The rectangular probe is placed parallel to the specimen to produce more uniform eddy current.•The pulsed eddy current sensor is installed on the mobile car for weld defect detection.•Three subsurface defects of weld were detected. In order to solve the problems of low detection efficiency, high labor intensity and poor working environment of large pressure vessel cylinder, the pulsed eddy current (PEC) nondestructive testing technology is used to detect the defects in the welding seam of the cylinder. The PEC sensor composed of rectangular probe coil and Hall sensor is installed on the mobile inspection platform to test two simulated cylinder weld samples. Results show that the signal curve of sample 1 without defect is gentle and without mutation, while the signal of sample 2 with defect has three mutation signals. Then, the X-ray testing method is used to detect the sample, radiograph confirmed that there are no defects on sample 1 and three porosity defects in sample 2. Through the comparison and analysis of the above two kinds of detection results, the feasibility of the detection method for weld subsurface defects is verified.