Mechanism and evaluation method of stress corrosion susceptibility of 904L stainless steel with optimized structure in seawater

The stress corrosion cracking (SCC) and the electrochemical behavior of 904 L stainless steel in a simulated seawater environment were investigated using slow strain rate testing (SSRT), electrochemical polarization, electrochemical impedance spectroscopy (EIS) and Mott-Schottky (M-S) curves. The sensitive potential range of 904 L stainless steel was determined by the fast and slow scan potential polarization curve, is − 950 mV_SCE ∼ 270 mV_SCE. Moreover, with the negative shift of applied potential, the toughness fracture characteristic of the three kinds of steel is reduced, and the sensitization state steel is the most obvious reduction. Finally, a practical formula for evaluating the SCC susceptibility of 904 L stainless steel was developed by integrating data from SSRT and fast and slow scan polarization curves.