Detection of corrosion on 304 stainless steel by acoustic emission measurement

Purpose - The purpose of this paper is to report an investigation of the acoustic emission (AE) characteristics of the corrosion process of 304 stainless steel in acidic NaCl solution.Design methodology approach - The corrosion behavior of a specimen with constant load in acidic NaCl solution was studied, and the AE signal characteristics of the corrosion process were analyzed. Stress corrosion cracking of the specimen was detected using the AE and electrochemical noise (EN) techniques, and the acquired data were compared.Findings - The results indicated that AE technology is very sensitive to the AE signals generated by 304 nitrogen controlled stainless steel in acidic NaCl solution. The characteristics of AE signals at different stages of the corrosion process are significantly different. Additionally, the AE test result is confirmed by the EN test results.Originality value - The characteristics of AE signals at different stages of the corrosion process are gained for the first time, which is an important guide by which to distinguishing different stages of corrosion.