Volume 12, Issue 5 (September 1984)
Analysis of Acoustic Emissions Generated During Stress Corrosion Cracking
Stress corrosion cracking of 300-M steel (Unified Numbering System [UNS] K4420) was monitored using an acoustic emission transducer. Stress corrosion cracking properties were altered through heat treatments and the relationships between the resulting microstructure and acoustic emission responses were studied. Prior austenite grain size exerted the maximum influence on the acoustic emission characteristics. Models were proposed to explain the grain size dependency of emission event peak amplitude and the relationships between crack velocity and the number of counts per event. The number of counts per event was also governed by material constants, applied stress intensity, and threshold level of detection of the acoustic emission system.