Point defect model for passivity breakdown on hyper-duplex stainless steel 2707 in solutions containing bromide at different temperatures

Passivity breakdown on HDSS 2707 has been studied and the electrochemical data are interpreted in terms of Point Defect Model. Pitting parameters determined, including polarizability at bl/s interface, defect annihilation rate, diffusion coefficient. The potential is demonstrated to be linearly related log [Br-], pH, square root scan rate (v1/2), follows a near-normal distribution. critical vacancy concentration calculated from PDM consistent with that estimated crystallographically chromic barrier layer, dominant point further confirmed by Mott-Schottky measurements.