Abstract
Acoustic emission with near-field detection and optical video microscope monitoring was proposed to investigate the pitting corrosion caused by a small magnesium-chloride droplet. Four types of the detected waveforms were characterized by the wavelet analysis to investigate the corrosion of work-hardened SUS304 stainless steel. After high-activity AE signals observed, the corrosion product sheet grew with or without low-activity AE signals. With the cross-section observations, the detected AE signals were mainly attributed to longitudinal and transverse cracking around the covered pitting, cracking of the oxidation products, and the early stage of corrosion potential fluctuation.