Practical Application of Acoustic Emission Detection for Welding Process (Report 2)

Detection of AE Signal from Hot Cracking

Abstract

AE of hot cracking has been monitored and quantitatively correlated with crack length for SUS 310S stainless steel on TIG welding. It was found that there exists a linear relationship between length of hot cracking and the total summation of AE counts, and the total summation of AE energy also.
AE signal from weld specimen can be classified three types of AE signal from theirs shape and frequency spectra by using the AE monitoring system.
The frequency spectra of their AE signals were distinguished, especially, the different distribution of frequency band from DC to 400 kHz. It is considered that the source of A type AE signal was generated at hot cracking, the type B one was generated from sound of friction between weld specimen and jig, and the type C was generated from arc noise only during welding.
These classification of AE signals could be useful for the practical application of acoustic emission monitoring to welding situations.