Effects of welding defects on the damage evolution of Q245R steel using acoustic emission and infrared thermography

Detecting welding defects is a key aspect in the safety assessment of pressure vessels. Using non-destructive testing methods to reveal influences of welding defects on the evolution of material damage is of great significance. In this paper, the damage evolution of Q245R steel with different welding defects was monitored by acoustic emission and infrared thermography technology. First, cluster analysis was used to reduce the effects of noise on acoustic emission signals. Then, differences in the characteristic parameters during the damage evolution were compared. Furthermore, the predominant peak frequency and time-frequency spectrum using fast Fourier transform and wavelet transform were investigated for acoustic emission waveforms, and temperature changes were monitored during damage evolution using thermal conductivity. The results indicated that the effects of different welding defects on the damage evolution of Q245R steel can be effectively revealed through the non-destructive testing technology combining acoustic emission and infrared thermography, which can provide a reference for evaluating the overall structural health of pressure vessels and reducing the failure risk.