Acoustic emission response of 304 stainless steel during constant load test in high temperature aqueous environment

Acoustic emission (AE) behavior of 304 stainless steel during constant load test in high temperature aqueous environment was investigated in situ and the corresponding fracture characteristic was examined carefully. The cumulative hits increase with stress intensity factor and two types of signals can be distinguished. According to the fracture morphology and amplitude distribution exponent analysis, it is believed that the high amplitude signals could be attributed to crack propagation and low amplitude ones are due to plastic deformation. The correlation between AE signal evolution and cracking process is discussed.

► Sudden increments of AE signals can be detected at high stress intensity factors. ► Two types of AE signals can be recognized based on signals amplitude. ► Not all the cracked area has a corresponding AE signal.