2019 Volume 73 Issue 6 Pages 347-351
Intergranular stress corrosion cracking（SCC）in sensitized 304 stainless steel was monitored using acoustic emission（AE）, corrosion potential, and visualization for Fe2＋ dissolution. The visualization revealed the location and timing of the SCC initiation and growth. Blast-type AE signals were detected in both the initial and growth stages of SCC, which were identified from the corrosion potential. In the initial stage, the AE and corrosion potential fluctuation was detected at relatively the same time, and pitting corrosion was observed. The AE sources in the initial stage were the evolution, movement, and departure of gas due to local cathodic reaction. In the growth stage, the AE was stronger than that in the initial stage, but its generation rate was relatively low and not related to the SCC growth rate. The AE source was the segregation of undissolved grain boundaries by tensile loading at the SCC tip.
