Study on the application of acoustic emission testing technique in monitoring 16Mn steel welding defects

In this paper, 16Mn steel was chosen as specimen for testing its welding defects by using acoustic emission technique, on which three-point bending test is carried out for monitoring the process of specimen's fracture under load. Meanwhile location analysis was conducted on welding crack region with linear location method, and the analysis on acoustic emission characteristic signals generated in the process of plastic deformation and welding crack propagation are carried out by using characteristic parameters analysis method, hence, the characteristic parameters' distribution range of each typical acoustic emission source is preliminarily determined. As shown by the research result, peak frequency of signal and frequency centroid are closely related to the nature of signal source, and based on these indicators, preliminary pattern recognition of noise sources and different defects sources may be implemented.