Understanding the non-steady electrochemical mechanism on SCC of 304 SS under applied polarization potentials

In this work, the non-steady electrochemical model on stress corrosion cracking (SCC) was established, which was verified by SCC of 304 SS with various microstructures. SCC mechanism depends on applied potentials including anodic dissolution (AD), hydrogen embrittlement (HE) and AD+HE, and the potential range for each mechanism was determined with the critical potentials on slow/fast scan potentiodynamic curves. The quantitative relationship of SCC susceptibility and applied potentials is acquired with the model, which is effective for assessing SCC. It was verified by 304 SS with various microstructures, which presents similar non-steady electrochemical characteristics and SCC susceptibility.