Fig. 5
From: The role of titanium in the initiation of localized corrosion of stainless steel 444
a 3D model geometry used for the finite element simulations. b Schematic of the reacting surfaces and boundary conditions employed in the presence of an inclusion. The radius of glass sheath (rglass), radius of microelectrode (rUME) and diameter of inclusion (s) were selected based on experimental parameters, with rUME = 2.35 µm, rglass = 22.56 µm, and s = 8 µm. c Extraction of local rate constants from PAC performed over a TiN inclusion [1] and passivated metal matrix [2]. Pure positive and negative feedback are shown for comparison purposes. The extracted rate constants are k1 = 2.0 ± 0.1 cm/s and k2 = 0.19 ± 0.01 cm/s
