金属材料局部腐蚀损伤过程的近场动力学模拟：进展与挑战

夏大海, 邓成满, 陈子光, 李天书, 胡文彬

Modeling Localized Corrosion Propagation of Metallic Materials by Peridynamics: Progresses and Challenges

XIA Dahai, DENG Chengman, CHEN Ziguang, LI Tianshu, HU Wenbin

图6 点蚀、缝隙腐蚀、晶间腐蚀、电偶腐蚀以及应力腐蚀开裂对应的PD二维初始条件和边界条件^{[60,70,72~74]}

Fig.6 Initial and boundary conditions of 2D in PD of pitting corrosion (a)^[60], crevice corrosion (b)^[70], intergranular corrosion (c)^[72], galvanic corrosion (d)^[73], and stress corrosion cracking (e)^[74] (X, Y—coordinates; C( x, 0)—concentration of material point x at t = 0; C_solid—concentration of solid node; $\frac{\partial C (x, t)}{\partial x_{2}}$ and $\frac{\partial C (x, t)}{\partial x_{1}}$ —derivative of concentration; C( x, 0) = C_solid, C( x, t) = 0, $\frac{\partial C (x, t)}{\partial x_{1}} = 0$ , and $\frac{\partial C (x, t)}{\partial x_{2}}$ = 0—there is no flux around the boundary of the metal, except over the solid/liquid interface. δ₀—subscripts are the values for the polar angle θ of the crevice; C₍_t_{≥ 0)} = 0—boundary concentration to the bulk dilute electrolyte; C₍_t_{= 0)} = 0—concentration of electrolyte; C₍_t_{= 0)} = C_solid—concentration of metal; C₍_t_{= 0)} = 0.99C_sat—concentration of the end of crevice. $\frac{\partial C}{\partial x}$ —derivative of concentration; C₀ = C_solid—concentration of intact metal; C( x, t)—concentration of material point x. $?^{2}$ ϕ—second derivative of potential; $?_{n}$ ϕ = $?$ ϕ·n —potential gradient, n is normal vector; i_c—cathode current density; i_a—anodic current densities. u—displacement with tensile stress, σ—tensile stress, L—length of the domain, E—elastic modulus)