Acoustic emission monitoring during open-morphological pitting corrosion of 304 stainless steel passivated in dilute nitric acid

Abstract Knowledge gaps exist concerning the acoustic emission (AE) during the pitting corrosion of open morphology. Here, we proposed a simple yet effective strategy to control the pitting evolution uncovered by lacy covers or corrosion products in a vertically positioned 304 stainless steel (304 SS) specimen that was pretreated by immersion in dilute nitric acid. The corrosion pit developed with a “head” and a “tail”, i.e., the open cavity and the corrosion products deposited below the pit head respectively, the evolution of which was monitored with by-stage AE signals. The AE sources associated with the open-morphology of pitting corrosion were discussed.