Research On Electromagnetic Ultrasonic Testing Technology For Butt Weld Of Steel Plate

Lamb wave is widely used in the detection of butt weld defect of steel plate. In order to solve the high requirement of traditional piezoelectric ultrasonic on the surface of the specimen, the electromagnetic ultrasonic testing technology (EMAT) is adopted to stimulate Lamb wave. On the basis of solving the Lamb wave frequency scatter curve diagram of 3mm thick steel plate by MATLAB programming, COMSOL software was used to simulate the propagation of characteristic guided waves in steel plate welds. The simulation results showed that the characteristic guided waves in steel plate welds had an obvious effect on defect identification, and the error was about 2%. The experimental design of electromagnetic ultrasonic excitation Lamb wave detection of rectangular through-hole defects in steel plate welds. The results show that the excited characteristic guided wave can effectively detect the position of the through-hole defect, and the positioning error is about 2.9-3.5%. Both simulation and experiment show that the electromagnetic ultrasonic Lamb wave detection method has obvious effect on the positioning of the butt weld defects of the steel plate.