Qualitative Analysis of Acoustics Emission Signal Parameter Character during the Bending Loading Course

In order to find the typical acoustic emission (AE) parameters for distinguishing the original specimen without being welded and the specimen with blowhole defect all made of WELDOX960 steel. Three-point bending test on the two specimens were conducted respectively. Firstly, from the procedural map, we deduced that the reason why there was such a sudden energy leap is because of the activities of welding crack, and the multistage energy release also because of the step by step propagation of welding crack in despite of any kind of welding defect. AE parameter distribution map and statistical distribution analysis results also validated the before-mentioned judgment. We found the parameter distribution map of amplitude, count, duration time and centroid frequency of the two specimens were distinctly different, thus those characters can be used as the indicator on its own for distinguishing the two kinds of AE source, i.e., the plastic deformation and the crack generation and propagation