Experimental Research of AE Inspection on Stress Corrosion Crack for Small Pressure Vessel

To study acoustic emission (AE) signals characteristics of stress corrosion crack (SCC) on in-service pressure vessels. The small pressure vessel with a pre-crack, filled 6% ferric chloride solution was monitored by AE technique. Conventional parameter-based approach and signal-based analysis were combined to deal with recorded AE signals, and micromorphologic observation and ray detection were performed for further verification. The results showed that the Kaiser effect of Q345R material is obvious, AE hits rate and amplitude & energy of the first pressure cycling was higher. Signal band is mainly distributed in 40 ∼ 400 KHz, Signal waveform was mainly composed of high -frequency (>100 KHz) expansion wave with larger amplitude & energy and low-frequency (<100 KHz) flexural wave with lesser amplitude & energy. The research results have a certain reference value for AE test on SCC for practical in-service pressure vessel.